West Nile Virus Response Plan


New York State Department of Health
May 2000


This report describes the plan that the New York State Department of Health, working in conjunction with other state agencies, local health departments, New York City, and the Centers for Disease Control and Prevention, has implemented to address the potential return of West Nile virus to New York State.

West Nile virus causes an arthropod-borne disease that was responsible for 62 cases of encephalitis, including 7 deaths, in New York City and surrounding counties during the summer and fall of 1999. Prior to the New York State outbreak, the virus had never before been identified in the Western Hemisphere. In addition to the human cases, West Nile virus infection was confirmed in hundreds of birds, mainly crows, as well as several horses and other domestic animals.

West Nile virus is transmitted primarily by the Culex pipiens mosquito, which feeds on both humans and birds. Because West Nile virus is new to the Western Hemisphere, no one can say with any certainty whether the virus has run its course or if the cycle of infection will begin anew when mosquitoes emerge from hibernation. To prepare for its possible recurrence, New York State organized a series of work groups to address the issue proactively, aggressively and fully, to protect New York State citizens. The work groups included representatives from New York State agencies, local health departments, New York City officials, and representatives from community, environmental and other non-governmental organizations.

This plan describes:

The New York State Department of Health and New York's local health units are garnering significant staff and fiscal resources to implement this plan. Although the unprecedented introduction of West Nile virus in 1999 was the precipitating event for strengthening the public health infrastructure as described in this plan, the West Nile virus outbreak serves only as a reminder that new disease outbreaks, whether arthropod-borne or not, can occur in the future. As New York moves forward to prevent a recurrence of West Nile virus disease, health departments must remain diligent and responsive to other emerging infections. This new infrastructure and communication network will form a cohesive multiagency approach to respond to other similar disease events. Even if West Nile virus does not recur in the northeast, there are other disease agents that pose threats to our general welfare and may require the very expertise developed as a result of this wakeup call for public health.

Implementation of this plan will require the dedicated cooperation and participation of local, state and federal agencies, community organizations, and the public. With a coordinated response, we can achieve the overall goal of this plan -- to minimize the risk of West Nile virus infection to humans and domestic animals by using a graded response that causes the least adverse impact on the environment.


The development of this New York State West Nile Virus Response Plan could not have been possible without the hard work of innumerable staff of the New York State Department of Health and of many other local, state, and federal agencies and private citizen groups. Staff of the following groups are specifically acknowledged for their significant role in developing this plan:

Centers for Disease Control and Prevention
Citizens Campaign for the Environment
Columbia County Department of Health
Cornell University
Dutchess County Department of Health
Fordham University
Nassau County Department of Health
National Audubon Society
Natural Resources Defense Council
New York City Department of Environmental Protection
New York City Department of Health and Mental Hygiene
New York State Association of County Health Officials
New York State Department of Agriculture and Markets
New York State Department of Environmental Conservation
Orange County Health Department
Putnam County Health Department
Rockland County Health Department
Saratoga County Public Health Nursing Service
Suffolk County Department of Health Services
Suffolk County Department of Public Works
Sullivan County Public Health Nursing
Ulster County Health Department
Westchester County Department of Health
Wildlife Conservation Society


ABDP Arthropod-Borne Disease Program
CDC Centers for Disease Control and Prevention
CSF Cerebrospinal fluid
DID Division of Infectious Disease, Wadsworth Center, New York State Department of Health
GIS Geographic Information System
ELISA Enzyme linked immunoassay
EPA United States Environmental Protection Agency
HIN Health Information Network
HIU Highly Infectious Unit of the Wadsworth Center
HPN Health Provider Network
ICR Initial case report
IGRs Insect Growth Regulators
IPM Integrated Pest Management
LHU Local Health Unit
NAS National Academy of Sciences
NVSL National Veterinary Services Laboratory
NWHC National Wildlife Health Center
NYSACHO New York State Association of County Health Officers
NYSAg&Mrkts New York State Department of Agriculture and Markets
NYC New York City
NYCDOHMH New York City Department of Health and Mental Hygiene
NYS New York State
NYSDEC New York State Department of Environmental Conservation
NYSDOH New York State Department of Health
PRNT Plaque reduction neutralization tests
PSA Public Service Announcement
RT-PCR Reverse transcriptase polymerase chain reaction
SLE Saint Louis Encephalitis
ULV Ultra low volume
USDA United States Department of Agriculture
WNV West Nile Virus
WPU Wildlife Pathology Unit of the New York State Department of Environmental Conservation

Prevention, Response and Control

  1. Introduction

    West Nile virus (WNV) is a member of the Japanese encephalitis complex of flaviviruses, transmissible by mosquitoes, and can cause febrile, sometimes fatal human illness. West Nile virus was first isolated in Uganda in 1937 from a febrile woman and was subsequently isolated from other human patients, birds and mosquitoes. It has a wide geographic distribution and has been involved in human disease outbreaks in Africa, southwest Asia and Europe. Until 1999, this virus had never been reported in the Western Hemisphere. Mosquitoes, primarily bird-feeding species, are the primary vectors of WNV, although virus has been isolated from other bird-feeding arthropods, including some tick species. The virus has been isolated from mammals in endemic areas, including mice, hamsters, camels, cattle, horses, dogs and lemurs. The natural transmission cycle of the virus involves a bird-mosquito cycle, but may include a tick-bird cycle where soft ticks (argasids) or hard ticks (ixodids) are found feeding on reservoir birds. The urban cycle of the disease requires species of mosquitoes that will feed on free-ranging or domestic birds and people.

    The unprecedented introduction of WNV into the metropolitan area of New York City (NYC) in the late summer of 1999 has resulted in a large-scale review of existing programs and required resources to address this threat. Representatives of several local health units (LHUs), State and Federal agencies met to address each of the significant surveillance and response issues associated with this mosquito-borne disease. As a result of these discussions and consultation with community groups, the New York State Department of Health (NYSDOH) has developed a set of complementary action plans designed to offer a degree of consistency in the approach taken among municipalities to prevent a further episode of this or other related arbovirus infections.

    Public health agencies must conduct surveillance to identify the presence of mosquito-borne disease agents, and be prepared to intervene using a variety of methods to mitigate further circulation of such disease agents in nature. Agencies must be prepared to use four fundamental approaches toward the management or control of these mosquito-borne agents: education, larval habitat source reduction, larval mosquito control and adult mosquito control, in that priority. This hierarchical approach from education, habitat modification, to control when required, will provide the best integration of strategies to assure the public's health. This plan describes a variety of steps to prevent a recurrence of the WNV outbreak and to assist the public health community to focus available resources on disease prevention. The plan may change as new scientific information becomes available. Therefore, recommended protocols will need to evolve with that new information.

  2. Objective

    To use a hierarchical response and control approach to prevent human and animal disease due to West Nile or other arboviruses.

  3. Implementation Plan
    1. Develop Prevention Strategies to be Implemented by Governmental Agencies

      Prevention strategies must be based on a well-planned, area-wide Integrated Pest Management (IPM) based program of mosquito control. IPM for mosquito control includes surveillance, education, source reduction, and larval and adult mosquito control. Surveillance and education issues are discussed in the following chapters of this plan.

      The foundation of any mosquito-borne disease control program includes mosquito prevention, through source reduction and larval control, and an educational campaign. Human disease may be prevented in an IPM-based control strategy. IPM can be cost-effective even in years when no disease agents are detected. When source reduction or larval control is not possible or has reached its maximum but insufficient potential, adulticiding either by ground or air, may be required to suppress populations of infected mosquitoes. This approach, however, is reactive in nature, and can result in the exposure of people to relatively broad-spectrum pesticides. Limiting mosquito populations before they become biting adults provides a margin of safety, should a pathogen be introduced into an area. In addition, larval control allows for the use of target-specific agents in definable areas, an environmental benefit over other methods. Individual homeowners can help reduce mosquito populations, but to be effective, additional mosquito management may need to be undertaken on an area-wide basis by trained personnel. An integrated IPM control program will require the cooperative efforts of all levels of government.

    2. Identify Integrated Mosquito Management Protocols (Larval and Adult Mosquitoes)

      This plan is based on a four-tiered hierarchical response for municipal management of mosquito-borne virus. These tiers establish, as of April 1, 2000, circumstances that may be present in any given municipality, and the types of activities that may be considered by the LHUs implementing comprehensive public health measures to control arboviral disease agents. Appendix A presents a decision matrix for use by the LHUs based on new surveillance data and the more detailed actions that may be conducted by the LHUs.

      Tier Circumstances Response
      I No historical or current evidence of virus (and LHUs not bordering those with historical evidence) - Level 1 education campaign
      - Enhanced passive human and bird surveillance
      - Consider adult mosquito surveillance, document species and distribution, lower lab testing priority
      - Consider larval mosquito surveillance
      - Consider local environmental assessments
      - Consider local disease risk assessments
      II Historical evidence of virus (and LHUs bordering those with historical evidence) - Level 1 enhanced education campaign
           General public
           Provider community
      - Local environmental assessments
      - Local disease risk assessments
      - Active human (only county with historical evidence) and bird surveillance
      - Larval mosquito surveillance
      - Larval mosquito habitat source reduction
      - Larval mosquito control
      - Adult mosquito surveillance and lab testing
      III Current evidence of WNV presence in individual locations (virus isolation or evidence of infection) - Level 2 or 3 education campaign
           General public
           Provider community
      - Active human and bird surveillance
      - Larval mosquito surveillance
      - Larval mosquito habitat source reduction
      - Larval mosquito control
      - Adult mosquito surveillance, lab testing
      - Adult mosquito control, ground application
      IV Current evidence of wide-spread WNV presence in multiple locations (virus isolation or evidence of infection) - Level 2, 3, or 4 education campaign
           General public
           Provider community
      - Active human and bird surveillance
      - Larval mosquito surveillance
      - Larval mosquito habitat source reduction
      - Larval mosquito control
      - Adult mosquito surveillance, lab testing
      - Adult mosquito control, ground application

      - Adult mosquito control, aerial application conditions. In general, ground application of pesticides should be the preferred method of control. Aerial application of insecticides for adult mosquito control should be considered only in Tier IV circumstances and only after careful consideration of the risk to human health by taking into account multiple factors, including the size of the vector population, the vectors' physiologic age, the density and proximity of human populations, the time of year, weather conditions, physiography of and accessibility to the area where the vector is located, rapidity of response required as determined by the seriousness of the public health threat, and the likelihood that vectors in nearby areas not subject to control measures will migrate from the area if not subject to control. Aerial spraying should be limited to the immediate area where the vector population has been documented to exist through vector surveillance and to adjacent areas considered at risk for imminent disease transmission.

      Note: The environmental assessments are overarching activities that LHUs need to initiate to begin to define the variety of environmental conditions that are present in the county, including areas that may support populations of mosquitoes (e.g., natural or man-made wetlands areas, abandoned swimming pools), environmentally sensitive areas that need to be protected, areas that may require surveillance to identify the potential breeding of immature mosquitoes, and areas that need to be excluded from any chemical-based mosquito control program. The NYSDEC has background information on the environmental assessment process. Disease risk assessments go a step further to consider the likelihood of human exposure to mosquitoes, to Culex mosquitoes specifically, to areas that may have already documented virus activity or areas that appear likely to support large numbers of Culex mosquitoes in the absence of intervention.

    3. Surveillance Data Interpretation
      1. Use of Bird/Mammal Surveillance System Data

        Bird and mammal surveillance data will be used by state and local agencies and institutions responsible for disease control along with surveillance data from human case reports, human surveillance testing, and mosquito testing. Some specific recommendations for use of bird/mammal surveillance data include the following:

        • If an increase in dead crow reports is noted, increased active surveillance for human cases, mosquito testing, and crows for laboratory testing should be undertaken.
        • Laboratory confirmation of WNV in any bird or mammal is one of several types of surveillance information that should be used as one indicator of the presence of WNV in a geographic area and the potential need for increased vector control activities.
        • In interpreting the evidence of the laboratory positive bird or mammal for concluding the presence of WNV in a geographic area, the following considerations should be included:
          • What are the probabilities of false positives and false negatives with the specific laboratory test used?
          • Does the laboratory test and/or clinical history support the infection being current rather than from a prior year's exposure?
          • Is there evidence that the positive bird or mammal acquired the infection locally, or was there a travel history or concern about migration such that the infection could have been acquired elsewhere?
          • Is the positive bird or mammal from an area near the identified outbreak, or did it jump over a geographic area not previously identified as having WNV?
          • Is there other supporting evidence of WNV in or near the geographic area, such as positive mosquitoes or human cases?
      2. Use of Mosquito Surveillance System Data

        In addition to human, bird or other animal surveillance systems employed by LHUs and other institutions, mosquito surveillance data can provide invaluable information in an effort to understand the complex virus cycle in nature. In fact, consideration of any mosquito control operations requires a concurrent effort to identify the mosquito species distribution, density and dynamics, so that targeted control efforts are directed to specific habitats, at a specific time, and in a specific formulation to best result in effective and efficient mosquito control. Some specific recommendations for the use of mosquito surveillance data include the following:

        • Municipalities that have had historical evidence of virus activity need to monitor the larval and adult mosquito populations to allow determination of effective timing and location of insecticidal and non-insecticidal control efforts.
        • If a municipality receives reports of multiple dead crows, the LHU needs to take immediate action to establish, or enhance existing adult mosquito collections in the area and lab testing to help determine whether a zone of local virus transmission exists.
        • Adult mosquito surveillance and lab testing needs to be immediately established, if not already in place, in residential areas in proximity to suspect horse or human cases of arboviral illness, especially in the absence of relevant case travel history.
        • Serological studies from sentinel bird surveillance may support the evidence of serological conversion and evidence of virus transmission. Sentinel flocks should be supported with complementary adult mosquito surveillance and lab testing to allow determination of dominant mosquito species and infection rates in those mosquitoes.
        • Larval and adult mosquito surveillance is required to document control efficacy. Identical collection efforts need to be conducted in the target intervention (spray) area as well as in a similar habitat not subject to the intervention (non-spray, or "control" area). In addition, pre- and post-intervention population assessments need to be made in both areas.
    4. Mosquito Management

      Mosquito management can be achieved by implementing one or a combination of the following, which are listed by category:

      Mosquito Control by Non-insecticide Methods

      1. Residential/Commercial:

        Most larval control work on residential and commercial properties must be done by the residents or owners themselves. It is the responsibility of government agencies to advise them where mosquitoes breed, what mosquitoes look like, and how to prevent breeding. Governmental agencies may provide assistance in conducting environmental sanitation efforts such as cleaning or flushing storm drains, removing tire piles, eliminating containers that may hold stagnant water, etc. Tools for public education include radio, TV, newspapers, pamphlets, schools, environmental organizations, etc.

        Mosquito larvae develop in standing water with an organic content. Therefore, property owners should be advised to:

        • Remove standing water from pool covers, abandoned pools, rain gutters, and any vessel on the property that can hold water for a period of time.
        • Introduce fish into ponds and marsh areas (residential/municipal). Some species of fish may require permits to be used.
      2. Municipal control of mosquito larvae:
        • To prevent standing water, federal, state and local governments must maintain the existing drainage structures on their properties such as preserves, sumps, recharge basins, sewage or wastewater treatment facilities, street catch basins, salt marsh ditches, upland streams, ponds, and pools (unless law dictates otherwise). IPM strategies to eliminate larval mosquito breeding should be pursued. Privately owned or operated sewer facilities should be maintained in a similar fashion to eliminate larval mosquito breeding.
        • Municipalities should be responsible for advising the towns and villages of what they can do to prevent mosquito breeding, and to enlist any support they may be able to provide toward the overall effort.
      3. Avoidance of adult mosquito bites by the general public
        • The public should be advised to install screens on windows and doors of homes and commercial buildings.
        • It is not necessary to limit any outdoor activities, unless there is evidence of mosquito-borne disease. If the WNV is identified in an area, the public should be advised of the following precautions they may choose to take to try to reduce the risk of being bitten by mosquitoes:
          • Minimize time spent outdoors between dusk and dawn.
          • Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time, or when mosquitoes are most active.
          • Consider using mosquito repellent, according to directions, when it is necessary to be outdoors.
      4. Avoidance of adult mosquito bites by outdoor workers
        • It is not necessary to change standard work health and safety practices outdoors, unless there is evidence of mosquito-borne disease.
        • If the WNV is identified in an area, workers should be advised of the precautions that they may choose to take to try to reduce the risk of mosquito bites:
          • Wear shoes, socks, long pants, and a long-sleeved shirt when outdoors for long periods of time or when mosquitoes are most active (between dusk and dawn). Maintain body fluids to avoid heat stress.
          • Consider the use of mosquito repellent, according to directions, when it is necessary to be outdoors for long periods or at times when mosquitoes are most active.

      Mosquito Control Through the Use of Insecticides

      1. Larvicides can be used to control mosquitoes in the aquatic stage before they become biting adults. This type of control generally has the least effect on non-target species and the environment. The use of larvicides may require a New York State Department of Environmental Conservation (NYSDEC) permit, and the product must be registered for use in New York.
        • Microbial larvicides such as Bacillus thuringiensis var. israelensis and Bacillus sphaericus can be used successfully in a broad range of freshwater habitats, but are somewhat unpredictable in salt marsh habitats.
        • Biochemical larvicides (insect growth regulators - IGRs) such as methoprene can also be used in a variety of habitats, and are especially effective in salt marshes. While expensive, solid, time-release pellets and briquets can provide sustained control in small areas, reducing labor costs. Sustained release methoprene products are not for use in known fish habitats.
        • Mono-molecular surface film larvicides can be used in polluted or artificial habitats, but should not be used where non-target insects are important resources. This eliminates most natural areas.
      2. Mosquito adulticides should be considered the least desirable method of control and only used when current isolations of virus and/or evidence of disease has been established. Currently available adulticides include organophosphates, pyrethrins, and pyrethroid-based insecticides. These may be applied by backpack or truck foggers, or fixed-wing or rotarywing aircraft. These materials have strengths and drawbacks that will influence which material is most appropriate for a given situation, and all must be applied according to NYSDEC regulations and label directions.
      3. Fixed wing aircraft should not be disqualified as an option to apply insecticides should there be an epidemic of arthropod-vectored disease. This method can apply the insecticide much more quickly to a wide area than other methods.
      4. Effective methods to control overwintering mosquitoes in hibernacula need to be investigated, and, if appropriate, applied judiciously in established adult mosquito resting areas (Culex and Anopheles mosquitoes overwinter as adults).
      5. If adulticides are used, either by land or aerial application, people may be exposed to them. Pesticide exposure carries some inherent risk to people. NYSDOH has considered what options are available to evaluate possible health effects from the spraying and has developed a surveillance plan that is included in Appendix B.
      6. The use of insecticides for mosquito control is accompanied by risks to non-target organisms and ecosystem function. Direct toxicity is the primary concern, and it may be reflected in fish or wildlife kills or in episodes of non-lethal effects which render exposed organisms susceptible to other sources of morbidity or mortality. Relative risks of the currently registered mosquito control pesticides, both larvicides and adulticides are described in Appendix C-1 through C-4. A description of methods to monitor adverse effects is under development and review at the New York State Department of Environmental Conservation.
    5. Roles and Responsibilities of the Local Health Units (LHUs), the State Department of Health (Regional and Central Offices), and Other Agencies
      1. Local Health Unit Roles and Responsibilities

        LHUs will conduct mosquito control activities. LHUs need to be aware and adhere, when appropriate, to the requirements of law (PHL 611) and regulations issued by NYSDOH (10 NYCRR 44) and by NYSDEC (Environmental Conservation Law, Articles 15, 24, and 33) and regulations (6 NYCRR Part 325-326). State reimbursement for local surveillance and control activities will be based on NYSDOH approval of appropriate activities conducted according to the four-tiered response plan (see Appendix D).

        • An LHU control program should follow the tiered IPM approach described earlier.
        • The control program should also:
          • ensure that mosquito control personnel are certified to apply insecticides,
          • obtain all permits required for application of insecticides,
          • evaluate control efficacy,
          • include public notification of the spraying schedule and of changes in the spraying schedule, and
          • ensure that the public has one telephone number for each municipality where they can call for information.
        • Municipalities need to be aware of and implement worker protection requirements in NYSDOL law (Labor Law Articles 2 and 28) and regulations (12 NYCRR Part 820 and by OSHA 29CFR 1910).
        • Municipalities will ensure that the public will be notified of any pesticide spraying schedules and locations within the NYSDEC notification time frames, and will also be notified as soon as possible of any changes to that schedule. The public will be notified of a central telephone number within the municipality where they can call for information.
        • Municipalities should prepare, in advance, spray maps that delineate possible target and non-target areas, i.e., wetlands, sensitive sites, farmland and other features that could impact pesticide applications. This would allow all issues regarding which areas need to be avoided, which insecticides are appropriate and other restrictions to be settled before a health threat emerges.
        • Municipalities should determine, in advance, what insecticides will be considered for use. As much as possible, each county should review the technical information to determine what choices they would have in various situations.
        • Municipalities should review NYSDEC laws and regulations that must be adhered to such as:
          • Environmental Conservation Law Article 15 B Aquatic Pesticide Permits
          • Environmental Conservation Law Article 24 B Freshwater Wetlands Permits
          • Title 6, NYSDEC Regulation Part 190 B Temporary Revocable Permits B This is normally covered as part of the Article 15 permit.
          • Title 6, NYSDEC Regulation Parts 325-326 - Purchase and Use of Pesticides
      2. NYSDEC Roles and Responsibilities
        • Provide a listing of acceptable insecticide products to be used for mosquito control.
        • Provide clearly understandable, practical limitations and restrictions pertaining to insecticide applications.
        • Process NYSDEC aquatic and/or wetlands permits for insecticide applications or wetland modifications (if needed).
        • Provide a written, statewide negative declaration for the use of Bacillus sphaericus and other appropriate larvicides for use as a guide by LHUs in preparing individual negative declarations.
        • Assist local government in compliance with relevant State environmental laws and regulations.
        • Assist other agencies in the development of technical guidelines for the use of adulticides, particularly aerial application.
        • NYSDEC is exploring alternatives to the state mandated reporting requirements for large (aerial) applications of insecticides. Presently, reporting by address is required, resulting in the loss of time and personnel. Reporting by zone, tied to a Geographic Information System (GIS) application, would be a much better approach, and would obtain the same information.
        • NYSDEC is providing a guidance document and remains available to assist involved agencies with labeling interpretations and clarifications.
        • NYSDEC and NYSDOH will provide assistance to involved parties in determining the proper terminology to be used for public notification notices and releases.
        • The NYSDEC/NYSDOH will have outreach staff to provide training and advise the municipalities on habitat reduction, personal protection, and insecticide use. This must be done before April 2000. DEC pesticide staff could inspect application sites, provide support in registered products listings, guidance in following label directions, and training and testing to certify pesticide applicators.
        • Attached (Appendix E) is the NYSDEC manual which provides:
          • the category and training level needed by a certified pesticide applicator for each type of application,
          • a listing of the insecticide products (larvicides and adulticides) registered for use in New York.
          • a listing of the ingredients and food crop tolerances where they exist. These are required if a pesticide application is to be made in a commercial agricultural area.
          • regulations and permits required for pesticide applications.
        • NYSDEC will commit to accelerated review of applications for registration of pesticides needed in control programs. The NYSDEC manual provides information on all state-registered products.
        • Technical information has been developed for the commonly used larvicides and adulticides to assist decision-makers in choosing and using an insecticide. The information about the products that could be considered by decision-makers includes effectiveness under different environmental conditions (e.g. temperature), environmental fate, environmental risks, public health risks, costs, availability of the equipment and man-power, regulatory requirements, etc. Some of this information will need to be obtained by localities (i.e. costs, availability of equipment and manpower). Information about registered pesticides, environmental risks, public health risks, environmental fate, and efficacy is contained in Appendices C-1 through C-4.
      3. NYSDOH Roles and Responsibilities
        • Provide staff to support LHUs with mosquito surveillance and control programs.
        • Provide consultation to LHUs regarding the appropriate response to the occurrence of WNV isolations or infections.
        • Update programmatic Environmental Impact Statement for statewide vector control activities.
        • Assist in the preparation of a brochure and other educational media on mosquito biology and control.
        • The NYSDOH, in conjunction with staff of the LHUs, has identified the following training and technical needs for LHU staff:
          • Development of comprehensive mosquito surveillance and control programs.
          • Evaluating adult and larval mosquito control activities.
          • Acquisition, management, and evaluation of mosquito surveillance data.
          • Understanding the state aid reimbursement process.
          • Compliance with state agency requirements.
          • Understanding options to increase public awareness and education about mosquitoes to promote personal responsibility supporting the prevention of mosquito breeding.

          Technical needs:

          • Identifying a local agency to assume responsibility for control activities including the availability of certified mosquito control personnel.
          • Developing a list of appropriate insecticides for use in mosquito control activities.
          • Identifying non-insecticidal techniques for mosquito control in sensitive areas.
          • Implementation of a response due to an outbreak of mosquito-borne virus activity.

        The NYSDOH is conducting a two-phase training program to address these needs, covering mosquito surveillance, mosquito identification and determination of control efficacy. This training program commenced in early spring and will continue with the individual counties on an ongoing basis. A plan for addressing the technical needs of the counties is also being developed.

Mosquito Surveillance

  1. Introduction

    Mosquito surveillance is an essential part of any mosquito-borne disease control program. As is true with the long-standing eastern equine encephalitis (EEE) surveillance program in New York State (NYS), any mosquito-borne disease surveillance system will require a commitment of personnel and equipment resources to understand the complex natural cycle of these viruses, their vectors and their natural hosts.

    The NYSDOH has developed a comprehensive strategy to begin to identify these issues and to begin to build the foundation upon which thorough mosquito-borne disease prevention can be built. The following guidelines are built around scientific and technical information that may change over time, and therefore, the plan will require constant review and revision as new information becomes available.

  2. Objective

    To determine the distribution and abundance of potential vectors of West Nile and other arboviruses.

  3. Implementation Plan
    1. Scope of Surveillance Activities
      1. Geographic Range of Surveillance

        As a direct result of the 1999 WNV outbreak, high priority mosquito surveillance will be conducted in New York City (NYC), six Lower Hudson Valley counties (Dutchess, Orange, Putnam, Rockland, Ulster, and Westchester), and in Long Island (Nassau and Suffolk counties). Selection of surveillance sites and surveillance techniques will be established during program training sessions with the counties. Other NYS counties will be provided training and consultation on a lower priority, unless evidence of current virus activity in mosquitoes, birds, or mammals dictates a revision of that strategy. The surveillance plan will remain flexible as municipalities develop new surveillance data, including virus isolations or evidence of virus exposure in animal hosts. Mosquito pool allocation will be based initially on the distribution and density of WNV activity during 1999, and will be subject to modification as seasonal surveillance information is generated.

      2. Level of Surveillance

        The purpose of mosquito surveillance is to determine the species composition, abundance, and geographic distribution of mosquito species within each county by collection of larval and adult mosquitoes. Adult mosquito specimens that are submitted for virus testing can also provide evidence of infection status. Counties will be provided program consultation and training as requirements and availability dictate. NYSDOH Program staff remain committed to all counties and will assist in surveillance efforts to the extent possible, even in counties with no history of arbovirus presence. In addition to the mosquito surveillance described in this section, LHUs may need to consider other potential arthropod vectors and animals, and their role in the cycle of arboviruses in nature.

        The action plan for mosquito surveillance includes:

        • Identify larval breeding sites using aerial and ground-based surveillance methods. Dipping is the standard method for sampling larvae (Appendix F).
        • Map larval breeding sites using GIS technology.
        • Identify potential vector species of WNV within each municipality through the collection of adult mosquitoes with miniature light traps baited with CO2, landing counts, and CDC gravid traps or oviposition traps (Appendix F).
        • Map distribution of vector species using GIS technology.
        • Submit potential vector species to NYS for virus testing.
      3. Regional coordination
        • Municipalities will submit a weekly summary of mosquito activity to the NYSDOH. The summary will be on a standardized, electronic form on the Health Information Network (HIN). This information may be made available for distribution to the public.
        • Municipalities will develop an electronic mail list consisting of representatives of all participating municipalities and the NYSDOH and NYSDEC. Representatives will receive weekly updates of mosquito activity throughout the region.
        • Municipalities will notify all representatives of regional consortium within one day of receiving results of positive virus isolation or a confirmed case of mosquito-borne diseases.
        • Municipalities will participate in quarterly meetings to discuss surveillance results and control strategy.
    2. Surveillance Activities

      The regional mosquito surveillance plan for WNV in the year 2000 is being modeled after the Eastern Equine Encephalitis (EEE) virus surveillance program that has been ongoing in NYS since 1984. Specific details of the regional surveillance activities will be included in a manual developed by the NYSDOH Arthropod-borne Disease Program (ABDP). A draft copy of this manual is included (Appendix G). Surveillance activities include the location and mapping of larval mosquito habitats, adult collection techniques, and the handling of specimens for submission to the Highly Infectious Unit (HIU) of the Wadsworth Laboratories for West Nile and other mosquito-borne virus processing. The HIU will process 400 pools/week for arboviral agents. Mosquito surveillance activities should begin no later than 01 May and last through September. Specimens for viral testing will be submitted weekly to the HIU starting the first week of June.

      1. Larval Mosquito Surveillance

        Surveillance activities for immature (larvae and pupae) mosquitoes involve the location, mapping, and characterization of aquatic habitats (mosquito breeding areas). Mosquito breeding can occur anywhere standing water is available. Examples are numerous and include tires, drums, pails, garbage cans, plant pots, storm drains, unchlorinated swimming pools, or discarded appliances containing water. Mosquito breeding also occurs in natural water-filled areas not subject to wind or wave action. These areas may be temporary, flooded areas, tidal or fresh water wetlands, flooded depressions, or stream edges where quiet water pools exist, or in municipal sewage or waste-water treatment plants.

      2. Adult Mosquito Surveillance

        Mosquito-borne viral pathogens in NYS may cause encephalitis in humans. EEE virus and WNV can also cause disease in an animal host. All involve wild animals, as non-clinical zoonotic hosts, and have unknown maintenance cycles with the exception of the California viruses which are maintained through transovarial and transstadial infection of the mosquito vectors. Infection in man occurs through the bite of an infected adult female mosquito. Thus, most vector surveillance activities are directed to the collection of this stage. Miniature light traps are considered the standard tool for surveillance of adult mosquito vectors. Lightweight and powered by four D-cell batteries, the trap is portable and can be used to sample a variety of adult mosquito habitats. For EEE virus and California viruses, these may be swamps and wooded areas. For WNV, the areas of concern are more urbanized. The trap collects primarily host-seeking female mosquitoes and the addition of CO2 in the form of dry ice as an attractant substantially increases the collection of mosquitoes. Its use is generally recommended for routine surveillance activities for mosquito-borne viruses. Details for adult mosquito surveillance protocols will be included in the NYSDOH Mosquito Surveillance and Control Manual. Municipalities may also use the NJ light trap for mosquito population monitoring. This trap uses AC current and a standard 25 watt light bulb to collect adult mosquitoes. Since the trap is generally designed to kill the insects attracted to it, this type of trap, although good for monitoring species distribution and density, is not to be used for collecting specimens to be submitted for virus testing.

      3. Mosquito Specimens - Laboratory Testing

        Not all mosquito species are appropriate for arbovirus testing. Therefore, only pools of certain species should be submitted for testing. Target species for laboratory submission vary by disease pathogen of concern. For EEE virus, Culiseta melanura is the primary vector species. For WNV, members of the genus Culex should be given priority for testing, in particular Cx. pipiens, Cx. restuans, and Cx. salinarius, and species associated with Culex pipiens to include Ae. japonicus, Ae. triseriatus, Ae. vexans, and Ae. sollicitans. Further protocol details are included in the NYSDOH Mosquito Surveillance and Control Manual. Mosquitoes should be grouped by species, site and week of collection into a group, or "pool" of 1-100 individual mosquitoes of the same species, collected at the same location during one week of collection activities.

        The pool allocation system for WNV testing in 2000 has been prioritized (by total number of pools available to a municipality) in order of decreasing importance based on these 1999 criteria:
        (In order from highest to lowest importance.)

        • - Municipalities that had human and animal disease due to WNV.
        • - Municipalities that had animal disease due to WNV and isolations of WNV from vector mosquitoes, but no human disease.
        • - Municipalities that had only isolations of WNV from vector mosquitoes.
        • - Municipalities adjacent to the WNV epidemic area but with no evidence of WNV in any surveillance system.

        Based on the above criteria, the following weekly pool allocation for municipalities conducting mosquito surveillance for WNV in the year 2000 is the initial allocation and is subject to weekly modification based on current surveillance data. The NYSDOH is working with the CDC to arrange additional testing capacity if needed. Consistent with vector-borne disease definitions included in 10 NYCRR 44, the definition of a public health threat is met with the identification of a single WNV positive mosquito pool.

        Initial Allocation:

        Municipality Weekly Pools
        New York City 90
        Nassau 45
        Suffolk 45
        Westchester 40
        Rockland 35
        Putnam 20
        Orange 20
        Dutchess 20
        Ulster 15
          Sub-Total 330
        Central New York (EEEV) 70
          Total 400
  4. Roles and Responsibilities of the LHUs and the NYSDOH
    1. LHU Roles and Responsibilities
      1. Municipalities requesting state aid under Article 6, Section 611 of the Public Health Law will submit state aid applications outlining their program objectives. Municipalities requesting state aid for surveillance only will file DOH 0627-2377 and municipalities requesting state aid for surveillance and control will file DOH 0627-2378 to the NYSDOH ABDP for review and approval. State aid applications will detail plans for surveillance or surveillance and control in terms of the objectives of the LHU in preventing human and animal arthropod-borne diseases. The application should be submitted prior to the start of the active mosquito surveillance season. State aid applications and materials may be obtained from Dr. John Howard (315-470-6756, johoward@mailbox.syr.edu).
      2. The LHU will identify surveillance sites and provide all personnel, either internally or contractually, necessary to conduct routine mosquito surveillance and control program. This will include personnel needed to conduct larval and adult mosquito surveillance and personnel qualified and trained in mosquito control activities including the application of insecticides if desired by the LHU.
        • Larval surveillance will include the location, mapping, characterization of mosquito breeding habitats, including use of GIS; the collection and identification of immature forms from larval habitats; and the determination of control options.
        • Adult surveillance will include collection, sorting, identification, pooling and submission of adult mosquitoes for laboratory testing, including maintaining the integrity of specimens for laboratory testing.
        • Record all data relative to mosquito surveillance activities.
    2. NYSDOH Roles and Responsibilities
      1. In the absence of LHU surveillance staff, the NYSDOH ABDP staff will assist in providing mosquito surveillance and laboratory specimen preparation. Depending on the number of LHUs requesting such assistance, this weekly support may need to be provided to several LHUs, thus diluting the quantity of data potentially obtained in any one LHU.
      2. Process state aid applications. The NYSDOH, ABDP will review state aid applications from municipalities conducting mosquito surveillance or mosquito surveillance and control activities. Review will include a determination of the appropriateness of the surveillance and control program to meet the stated goals and objectives of the LHU. Municipalities submitting incorrect or incomplete applications will be notified promptly so that corrected applications can be resubmitted in a timely fashion.
      3. Conduct comprehensive training for LHU mosquito surveillance personnel. Training will be conducted by staff of the ABDP and other appropriate agencies. Training will occur at two times:
        1. A four-day training program in March, 2000 to be held in Albany and to be attended by designated mosquito surveillance personnel from participating LHUs. Training offered includes basic mosquito biology; larval mosquito identification; guidelines for conducting immature and adult mosquito surveillance; NYSDEC guidelines for pesticide use. Following completion of the training program, loaned mosquito surveillance kits will be distributed to LHUs.
        2. A three to four day training program in early May, 2000 in Armonk (Westchester County) to teach adult mosquito identification, sorting and pooling for laboratory submission; teach the completion of collection and submission data forms and data recording; teach the preparation of adult mosquito reference collections. LHU personnel will bring fresh-caught adult mosquitoes to the training program each day.
      4. At appropriate time intervals or at the request of the LHU, staff of the ABDP will provide on-site assistance to LHUs to maintain the scientific integrity of the mosquito surveillance program. Appendix F contains draft forms, prepared by the ABDP, for use by municipalities in recording and summarizing larval and adult mosquito collection data and submission of vector specimens. Included are:
        • mosquito breeding habitat description form,
        • weekly miniature light trap collection form,
        • CDC gravid trap adult and egg raft form,
        • laboratory submission summary form,
        • summary of miniature light trap collections,
        • mosquito/tissue laboratory submission form (this form is in development)
      5. The NYSDOH, in conjunction with staff of the LHUs, has identified the following training, technical and contractual needs:
        1. Training needs:
          • Larval and adult mosquito collection methods.
          • Larval and adult mosquito identification to species.
          • Preparation of larval and adult mosquito reference specimens.
          • Handling techniques to ensure integrity of specimens submitted for lab testing.
          • Proper completion of all standardized data forms.
          • Methods to ensure compliance with pesticide application regulations.
          • Evaluation of mosquito collection data.
          • Options for larval and adult mosquito control and for increasing public awareness and education regarding mosquitoes.
          • State aid reimbursement process.
          • Compliance with agency requirements
          • NYSDEC Pesticide Applicator Certification training if in house pesticide applications are to be performed (counties should contact NYSDEC concerning appropriate licensing).
        2. Technical Needs:
          • Properly trained personnel.
          • Mosquito collection equipment (expendable & non-expendable supplies).
          • Mosquito sorting materials (expendable & non-expendable supplies).
          • Dedicated laboratory support for testing of adult mosquito specimens.
          • NYSDEC Certified pesticide applicators.
        3. Contractual Needs:

          State contracts should facilitate the municipality purchasing process and thereby increase the resource availability of the aforementioned items. LHUs should be given access to existing State contracts or newly created NYS contracts for:

          • Mosquito surveillance equipment which would include mosquito traps (e.g. NJ, CDC, gravid), rechargeable 6V batteries, battery chargers, CO2 regulators, CO2 canisters, dry ice, and any other related items.
          • Sentinel bird surveillance equipment (e.g. chickens, cages, feed, etc.).

Bird/Mammal Surveillance

  1. Introduction

    As in the previous WNV outbreak, birds (especially crows) and mammals may be important sentinels for the virus, and thus may provide early warnings in time for control actions to be implemented to prevent human cases and impacts on livestock, pets, and wildlife.

  2. Objectives

    Develop effective and efficient surveillance systems for WNV using birds and mammals.

    Insure that handling of wildlife occurs under required state and federal licenses.

    Collect all bird and mammal surveillance samples according to humane considerations and standard veterinary care guidelines.

    Provide clear guidelines for interpretation of laboratory test results.

    Provide rapid reports of surveillance results to agencies and the public, while providing appropriate confidentiality protections to individual bird/animal owners, veterinarians, and institutions submitting specimens.

  3. Implementation Plan
    1. All Bird/Mammal Surveillance Systems

      Detailed plans for the specific types of bird and mammal WNV surveillance are provided in separate sections below. Activities that apply to all the types of bird/mammal surveillance include:

      • In regard to permits for handling wildlife, local agencies submitting birds for WNV-related necropsies to the NYS Department of Environmental Conservation's (NYSDEC) Wildlife Pathology Unit (WPU) are covered under the WPU's state permit for wild bird collection. The New York office of the USDA, Wildlife Services, will assist the WPU in obtaining the appropriate federal permits for county health departments for handling wild bird species. Those agencies contracting out for bird collection will need to require the contracting agencies to obtain appropriate federal permits.
      • To minimize the potential impact on individual animals and populations of animals in conducting WNV surveillance, samples for WNV surveillance will be obtained, when possible, from animals that have died of the disease or other causes, rather than taking samples from live animals. It is anticipated that the only samples to be taken on live animals would be a blood specimen for antibody testing, although potentially a veterinarian may also take a cerebrospinal fluid (CSF) specimen on an ill animal for diagnostic purposes. To reduce the stress on sentinel birds or mammals in drawing blood specimens, if possible, specimens should be utilized for more than one diagnostic test, for example, other surveillance tests required for control of other disease agents.
      • Clear guidelines for interpretation of laboratory tests will be developed by the NYSDOH's Wadsworth Center and any other laboratories performing testing, such as Cornell University's Veterinary Diagnostic Laboratory. This is because of the need to determine whether test results indicate current or previous infection, to avoid taking public health actions based on false positive or false negative results, and to avoid providing an inaccurate diagnosis to owners and veterinarians attempting to determine the cause of an illness in a pet or domestic animal. This issue will be particularly critical for interpretation of results from single serologic specimens or from other screening tests that are developed. Testing of birds and mammals and reporting of results by laboratories will occur in as timely a manner as possible, allowing for appropriate quality control. Any positive laboratory results for geographic outlying areas (areas beyond the identified area of the outbreak or its perimeter) will be rechecked for quality control purposes.
      • Rapid sharing of surveillance results with agencies and the public is essential for development of appropriate disease control measures. This will be accomplished by using NYSDOH's Health Information Network (HIN)/Health Provider Network (HPN) for all types of bird/mammal surveillance. However, as with human surveillance, protection of confidentiality is also important in regards to bird and mammal reports and testing. Individuals and agencies have understandable concerns about participating in surveillance and reporting if identifying information is released, and such information is not needed for effective participation in disease control decisions. Thus, identifying information will not be provided to agencies outside of the jurisdiction managing the outbreak, and will not be released to the public by the agencies with access to the information. Identifying information that will be protected to preserve confidentiality and to encourage participation in surveillance will include animal owner's name and street address, veterinarian's name and street address, name and address of individual or institution submitting specimen, and detailed species of bird or mammal. In addition, WNV test results of individual birds will not be routinely reported back to the specific individual submitting the bird, although summary level information will be provided by local health agencies to the public.
      • Summary tables will be automatically updated within 24 hours of results being available to local agencies, and can be downloaded by staff with WNV HIN/HPN access for any specified time periods.
    2. Ill or Dead Wild Birds

      In conjunction with their local and state partners, NYSDOH will continue to place a high priority for WNV surveillance on information from ill or dead wild birds. This surveillance involves two components: a reporting system for sightings of ill or dead birds to track possible increases due to a reappearance of WNV, and testing of selected ill and dead birds for the disease. This surveillance system requires those seeing birds ill with neurologic signs or dead to report them, including detailed date and location information, to their LHU. The effectiveness of ill or dead bird reporting will be enhanced by collaboration with those groups and individuals most likely to find ill or dead birds, such as agencies whose employees spend considerable time out of doors (parks, zoos, wildlife, transportation, etc.), and members of birding and outdoor recreational organizations. The LHU should record all reports of ill or dead birds via the HIN (Appendix H).

      Ill or dead birds will be necropsied by the WPU at its facility in the Albany, New York, area, according to specific submission and testing guidelines (Appendix I). If bird necropsies are performed within NYS by other private or public agencies, similar guidelines will need to be developed in conjunction with NYSDOH for specimen handling and submission. Specifications for the WPU necropsy system include the following:

      • Because of their sensitivity and specificity for WNV, crows will receive priority for necropsies, particularly if they are reported as ill or freshly dead (within the past 24 hours). Prioritization of the specimens for necropsy will reflect NYSDOH priorities for WNV surveillance and disease control activities.
      • However, recognizing that WNV is only one of thousands of causes of illness and death in birds, the WPU will continue to evaluate ill and dead birds for other causes of death.
      • Detailed bird submission protocols and forms have been developed (Appendix H). Waterproof tags pre-stamped with necropsy numbers for bird submission have been provided by the WPU to local agencies.
      • Leak-proof, reusable coolers (ice chests) are recommended for purchase by local agencies for bird submissions. Containers must not be similar to the shipping containers used for rabies submissions, in order to avoid misrouting of rabies and WNV specimens. They should be marked with indelible ink with the county name, address, and phone number, so that the WPU can ship them back to the local agencies after receiving the birds. Local agencies may also use disposable leak-proof, sturdy shipping containers, but this is anticipated to be more costly for the local agencies.
      • As recommended by the CDC WNV guidelines, all bird necropsies will be done at a BSL2 facility. If necropsies and WNV laboratory testing procedures are conducted in areas of the state without WNV, the extra security provided by a BSL3 facility should be considered.
      • Any rapid screening tests developed for WNV, for example, immunohistochemistry or immunofluorescence, will be utilized by necropsy labs on specimens as appropriate. Guidelines will be developed by Wadsworth Center and other laboratories performing such tests to interpret results, reduce false positives and negatives, and determine which specimens to submit for further testing.

      NYSDOH's Wadsworth Center will perform the WNV laboratory testing for bird surveillance specimens under the following specifications:

      • Wadsworth Center will provide guidelines for bird sample preparation and shipment for the WPU and any other agencies necropsying birds.
      • The Wadsworth Center will test a maximum of 100 crows per week for WNV, and other species as resources permit. Testing will be done by NYSDOH in consultation with the WPU based on the temporal and geographic patterns of the disease and need for surveillance information.
      • Birds for WNV testing beyond the capacity of the Wadsworth Center will be tested for WNV at laboratories other than NYSDOH's Wadsworth Laboratory (such as Cornell University's Veterinary Diagnostic Laboratory, the National Wildlife Health Center, {NWHC}, or Connecticut) as their resources permit.
      • NWHC will be used as a confirmatory reference laboratory for any NYS test results as needed, within its capacity for testing.
    3. Sentinel Birds (Testing of Asymptomatic Birds)

      For other arboviruses, sentinel birds have proven to be an important surveillance tool. The CDC has determined that chickens are a safe and recommended species for sentinel bird flocks.

      • Where feasible, emphasis will be placed on establishing partnerships and training to accomplish specimen collection. Prioritization for sampling and testing will be provided to those counties that experienced the outbreak last year or were contiguous with counties experiencing the outbreak. The New York State Department of Agriculture and Markets (NYSAg&Mrkts) will provide any requested training, consultation, and animal care guidelines for NYSDOH personnel involved in the safe and humane establishment of sentinel chicken flocks and collection of serologic specimens.
      • NYSDOH's Wadsworth Center will test up to 300 sentinel bird serologic specimens every other week collected in conjunction with surveillance conducted by NYSDOH staff or those authorized by NYSDOH to submit samples.
      • The NYSAg&Mrkts will work with the NYCDOH to establish sentinel chicken surveillance, with serologic specimens to be tested by Cornell University's Veterinary Diagnostic Laboratory.
      • The WPU and New York office of the USDA Wildlife Services will identify options for collecting specimens for WNV testing from wild birds killed in connection with wildlife damage projects to protect agriculture, property, and human health and safety throughout the state. The bird species will likely include gulls, crows, Canada geese, starlings, and pigeons. These could include birds removed for nuisance control from landfills and airports, or in local Canada geese roundups. Live birds tested could also include wild maintained bird flocks such as those in game farms.
      • The NYSAg&Mrkts will assist NYSDOH in identifying options for testing existing flocks of domestic birds. These birds could include those that already have routine blood samples taken, such as birds going to shows, birds in existing flocks that could be easily tested (for example, 4-H birds), or birds on egg farms, etc.
      • A coordinated and comprehensive plan will be developed among the agencies participating in sentinel bird surveillance for sampling a sufficient number of birds to provide appropriate representation of a geographic area. For example, if existing domestic bird flocks are used or sentinel surveillance flocks are established, efforts should be made to sample a minimum of six birds per area, and six areas per county, at least every other week.
      • The initial priority for testing at Wadsworth Center will be for chicken sera. The Wadsworth Center will offer testing of chicken serum samples to the counties affected by the 1999 outbreak (Nassau, Suffolk, Westchester, and Rockland), collected in the initial week that testing is available, and every other week thereafter. Testing of additional specimens from counties in the region of the previous outbreak may also be available. Other collection timetables (for example, testing birds every week) can be developed with NYSDOH within testing limits. NYC is intending to develop their own contracts for sentinel bird testing.
      • Mechanisms will need to be developed to distinguish previous from current infections. These may include testing hatch year birds that were not alive the previous year or requiring a four-fold rise in titer between two specimens taken two weeks apart.
      • For collection and testing of wild birds as sentinels, county and state agencies will consult with and request assistance from the New York office of the USDA Wildlife Services as resources permit. USDA Wildlife Services will seek additional funding from the USDA to support collection of wild birds and mammals.
      • The NWHC will be used as a confirmatory reference laboratory for New York's results as needed, within its capacity for testing.
    4. Mammals Submitted for Rabies Testing

      In NYS, mammals that have died of encephalitis are more likely to have died of rabies than WNV, and rabies can be transmitted to people by those mammals before they die (unlike WNV which has no direct transmission between animals and people). Thus, it continues to be critical that all mammals with neurologic signs, or that have contact that could result in rabies exposure to people, pets, or domestic animals, or that meet other guidelines for rabies testing promulgated by the NYSDOH Wadsworth Center's Rabies Laboratory, be submitted for rabies testing to either the Wadsworth Center's Rabies Laboratory or the NYC Rabies Laboratory, according to the guidelines established by those laboratories. WNV testing of dead mammals that have been submitted for rabies testing will take place according to the following guidelines:

      • Rabies-negative mammals will be tested for WNV as resources permit, with a priority for rabies-negative horses from the WNV-affected area because of the previous incidence of illness and death in horses. The Wadsworth Center Rabies Laboratory will work with the NYC Rabies Laboratory to facilitate WNV testing of appropriate rabies-negative horses tested by the NYC laboratory from the WNV-affected area.
      • Other domestic and wild species will be tested as resources permit, and for research purposes to document the frequency of WNV-related illness and death in mammals.
      • The USDA National Veterinary Services Laboratory (NVSL) and the NWHC will be used as confirmatory reference laboratories for New York's results as needed, within their capacity for testing.
    5. Ill Owned Animals (Domestic Mammals, Pets, Poultry)

      Of all the types of bird/mammal surveillance systems for WNV, surveillance by testing ill animals is likely to be the least sensitive and specific system, because most animals that become ill with clinical signs of encephalitis are more likely to have other causes of illness than WNV. However, occasional cases of WNV infection may be detected by laboratory testing, particularly in horses, and such information will be utilized as part of the geographic and temporal surveillance for the disease. Parameters for evaluation and testing ill animals for WNV include the following:

      • Owned animals with neurologic signs should receive a veterinary evaluation and appropriate diagnostic testing, including both rabies and WNV within the differential diagnosis list, particularly if the animal is from a geographic area with identified WNV infection.
      • If WNV is considered to be a possible diagnosis (based on potential exposures in a WNV infected area), acute and convalescent serologic specimens should be taken. Whether CSF specimen testing will be valuable has yet to be determined.
      • Case definitions to be utilized in determining the need for testing, and guidelines for interpreting laboratory test results, particularly for single serologic specimens, will be developed jointly by the NYSAg&Mrkts and NYSDOH.
      • Private practice veterinarians with questions about whether WNV testing is indicated should contact the NYSAg&Mrkts.
      • Laboratory testing of ill animals will be conducted by Cornell University's State Veterinary Diagnostic Laboratory, under the supervision of NYSAg&Mrkts.
      • The USDA NVSL will be used as a confirmatory reference laboratory for New York's results as needed, within its capacity for testing.
      • Laboratory testing of serologic specimens from asymptomatic mammals for surveillance purposes will also be conducted by Cornell University's State Veterinary Diagnostic Laboratory, under the supervision of NYSAg&Mrkts.
    6. Surveillance Priorities by Geographic Locations

      On the next page is a summary of the types of bird/mammal surveillance activities described above. As indicated above, some of these activities are likely to be more productive in detecting cases (such as testing dead crows) than others (such as testing dead mammals). Individual jurisdictions are encouraged to develop their own priorities for surveillance as their resources permit. The following recommendations may be considered in determining the types of surveillance to implement depending on the likelihood of a WNV outbreak, based on past year and new surveillance information. As new positive cases occur, of course, counties will move from one priority area to another.

      NYSDOH recommended activities are indicated by an R; those activities of a lower priority that counties may consider doing are indicated with an X. Footnotes below define active and passive surveillance in reference to the Prevention, Response, and Control section of the Plan:

      1 = components of a passive surveillance system;
      2 = components of an active surveillance system.

Geographic areas or counties: With evidence of current or past year infection Bordering areas in NYS or other states with current or past year infection With isolated positive birds or mammals, with evidence of movement from infected counties Not bordering infected areas; no positive test results
Examples Westchester, Rockland, Nassau, Suffolk Counties, NYC Putnam, Orange, Dutchess Counties   all other counties
LHU records phone calls about dead bird sightings1 R R R R
Provide information to press and public about how to report dead bird sightings1 R R R R
Submit dead crows for necropsy and WNV testing1 R R R R
Consider testing of other dead bird species for WNV, if testing resources available1 X X    
Phone appropriate partners (veterinarians, local Audubon, parks dept., wildlife rehabilitators) about system for reporting dead birds1 R R R X
Weekly, phone appropriate partners (Audubon, parks, wildlife rehabilitators) to seek out reports of dead crows2 X R    
Active search for dead crows at roosting sites, landfills, parks, etc.2 X R R  
Collect sera from sentinel adult wild birds2   X    
Collect sera from sentinel hatch-year wild birds2 X      
Collect sera from symptomatic mammals2 X X    
Collect sera from sentinel chicken flocks2 X X    
Collect sera from asymptomatic mammals2   X    
Test rabies-negative horses1 R R R R
Test rabies-negative pets and other species of domestic mammals2 X X X  
Test rabies-negative wildlife2 X X X  
Weekly, phone select veterinarians for reports of ill animals2   X    

See footnotes and key to "R" and "X" above table.

Human Surveillance

  1. Introduction

    In response to the unprecedented outbreak of WNV encephalitis in the greater New York metropolitan area during the Summer and Fall of 1999, the LHUs, in coordination with the NYSDOH, need to enhance surveillance for viral encephalitis to improve the ability to promptly detect a recurrent human outbreak next summer, should one occur. An essential component of an enhanced surveillance program for viral encephalitis includes the need to ensure rapid and complete laboratory diagnosis of all suspect cases. In addition, human surveillance is just one component of an effective arboviral surveillance program, and should be coordinated with mosquito and avian surveillance programs. Information from all of these programs should be used to determine the need for mosquito control efforts to prevent future outbreaks of WNV.

    Encephalitis and viral meningitis are two of 64 reportable diseases and conditions in NYS. Physicians are required to report all suspect cases to LHUs in NYS. However, physician reporting in general is not as reliable as laboratory-based reporting. Since most cases of encephalitis are diagnosed based on clinical criteria, and the absence of bacterial pathogens on microbial testing of cerebrospinal fluid (CSF), significant under-reporting of encephalitis is likely.

    Therefore to ensure detection of a recurrent human outbreak, enhanced passive surveillance for viral encephalitis should be implemented by all jurisdictions in NYS. Active surveillance should be implemented by those areas most affected by the 1999 WNV outbreak based on previous documentation of WNV in mosquitoes, birds, animals or humans last year. Surveillance for WNV encephalitis will need to be implemented in the spring when mosquito activity begins and continue through the Fall until several weeks after the first frost.

  2. Objective

    To enhance surveillance for West Nile viral encephalitis and improve our ability to promptly detect a recurrent human outbreak.

  3. Implementation Plan
    1. Surveillance Guidelines for WNV Encephalitis.

      The following options for WNV surveillance are based on level of risk for a recurrent outbreak in 2000. New York City and all counties in NYS should implement enhanced passive surveillance for encephalitis this Spring through the Fall (May - October). Jurisdictions where significant WNV activity was detected in humans, birds, animals and/or mosquitoes (NYC; Nassau, Suffolk, Westchester, and Rockland Counties) should implement more active surveillance.

      1. Enhanced Passive Case Surveillance (Recommended for all counties)
        1. Enhanced passive surveillance for viral encephalitis during May - October.
          1. Broadcast facsimile alerts and mailings should be sent to hospitals and physicians regarding the importance of physician reporting, criteria for reporting and instructions for submission of appropriate laboratory specimens (CSF, acute and convalescent sera, brain tissue {fatal cases}) for WNV testing. A template alert is being developed by the NYSDOH and can be modified as needed by the LHUs. An initial general alert summarizing the 1999 outbreak and outlining criteria for reporting and laboratory testing should be sent to all hospitals and selected physicians in NYS. In the areas most affected by the 1999 outbreak (NYC; Nassau, Rockland, Suffolk, and Westchester Counties), these should be followed by monthly updates to hospitals, with continuing reminders to report suspect cases.
          2. Since a negative reverse transcriptase polymerase chain reaction (RT-PCR) or enzyme linked immunoassay (ELISA) test on a specimen taken soon after illness onset (< 8 days) does not rule out arboviral infection, convalescent sera is needed to definitively determine if WNV infection is present or absent. Therefore, LHUs will ensure that convalescent sera is obtained on all suspected case-patients with encephalitis of unknown etiology, if acute sera or CSF obtained < 8 days after illness onset is negative for WNV.
        2. Commercial laboratory surveillance for sero-positive cases of St. Louis Encephalitis (SLE) and other arboviruses. Since WNV may cross-react with SLE on serologic testing, cases that are reported as SLE-positive based on serologic testing, should be retested by the NYSDOH for WNV and other arboviruses by serologic (plaque reduction neutralization tests) or viral assays to differentiate which flavivirus is the likely etiologic agent. The NYSDOH will contact the major commercial laboratories in April 2000 to remind them of the requirement to report patients with positive arboviral serologies (including SLE) to the LHUs.
      2. Active Case Surveillance (One or more of the following options should be done by areas most affected by 1999 outbreak {NYC; Nassau, Suffolk, Westchester, and Rockland Counties} and all areas if viral activity is detected in their jurisdiction in 2000 by human, mosquito or avian surveillance.)
        1. Active surveillance by weekly contact with key medical staff (e.g., infectious disease, neurology or intensive care subspecialists) at sentinel acute care hospitals regarding potential cases of viral encephalitis and viral meningitis. (Viral meningitis cases should be restricted to cases > 2 years of age given the high background rate of enteroviral meningitis in this age group.) LHUs will ensure that appropriate laboratory specimens are obtained on all suspect cases and tested for WNV.
        2. Laboratory-based surveillance at sentinel hospitals. LHUs will ask laboratory staff to store all spinal fluid samples that have parameters suggestive of a viral cause of infection (e.g., increased protein, pleocytosis and negative bacterial gram stain and culture). Samples will be collected weekly and screened for arboviruses by IgM-capture ELISA and/or RT-PCR testing. This laboratory-based system will provide a back-up to ensure that viral meningo-encephalitis cases that are not reported by clinicians are tested for arthropod-borne viruses.
        3. Retrospective surveillance for patients discharged with a diagnosis of encephalitis\aseptic meningitis of unknown etiology. LHUs will ask sentinel hospitals to search their databases for patients discharged with specific ICD codes. Hospital laboratory directors will be contacted to determine if sera or CSF are available on identified suspect cases and, if so, arrangements will made for testing at Wadsworth Center. Patients without available clinical specimens will be contacted to obtain convalescent sera.
      3. Non-traditional Arboviral Surveillance Methods (Potential alternative options to be considered by jurisdictions if resources available.)
        1. Monitor existing clinical datasets (911 data, managed care visits, nurses' hotlines) to detect increases in milder illnesses that may represent West Nile virus (e.g, fever/rash or fever/lymphadenopathy).
        2. Establish surveillance for liver disease or myocarditis of unknown etiology.
        3. Conduct laboratory surveillance to monitor volume of tests requested for other causes of encephalitis (e.g., Herpes simplex).
    2. Surveillance Criteria for Human Encephalitis and Meningitis

      During the 1999 outbreak, two-thirds of the encephalitis cases were associated with severe muscle weakness. Documentation of muscle weakness was based on neurologic examination and/or EMG findings. Therefore, case ascertainment should include encephalitis with muscle weakness, which may be more likely to represent WNV than other viral causes of encephalitis. The background rate of viral meningitis is significantly higher than encephalitis, and mostly due to enteroviruses during the summer and fall months. Therefore, the decision to include viral meningitis in the surveillance criteria needs to recognize that the increase in caseload may improve case detection but will generate significantly more testing requests. To lessen the laboratory burden of testing cases due to enteroviral meningitis, which is more common among young children, case criteria will restrict aseptic meningitis cases to children aged 2 years or older.

      1. Recommended Criteria for Suspect Case of WNV:

        Any adult or pediatric patient with viral encephalitis (Criteria a, b and c below) with or without associated muscle weakness (Criteria d):

        1. Fever 38.0o C or 100o F, and
        2. Altered mental status (altered level of consciousness, agitation, lethargy) and/or other evidence of cortical involvement (e.g., focal neurologic findings, seizures), and
        3. CSF pleocytosis with predominant lymphocytes and/or elevated protein and a negative gram stain and culture, with our without
        4. Muscle weakness (especially flaccid paralysis) confirmed by neurologic exam or by EMG.

        Any adult or pediatric (aged 2 years or older) patient with presumptive aseptic meningitis (fever, headache, stiff neck and/or other meningeal signs, with CSF pleocytosis with predominant lymphocytes and moderately elevated protein, and a negative gram stain and culture).

    3. Laboratory Testing for WNV

      All suspect cases will first be reported to the LHU using the initial case report form (Appendix J). LHU staff will screen reports to assess that the clinical presentation meets the case criteria for viral meningo-encephalitis. If the case meets the surveillance criteria, the hospital or physician will be provided information on how to submit appropriate diagnostic specimens for testing.

      The NYSDOH Wadsworth Laboratory will perform viral testing for WNV, including reverse transcriptase polymerase chain reaction (RT-PCR) testing, enzyme linked immunoassays (ELISA), and plaque reduction neutralization tests (PRNT).

      Health care providers will be informed that appropriate specimens for testing include:

      • CSF - Testing by IgM capture ELISA and RT-PCR.
      • Sera - Acute and convalescent testing by IgM Capture and IgG ELISA testing.
      • IgM-positive sera should be confirmed by convalescent sera IgG (ELISA and PRNT).
      • Brain tissue - PCR and viral culture.

      LHUs need to encourage physicians and laboratories to complete all essential information on the laboratory submission forms, including clinical and risk factor data, and symptom onset and specimen collection dates.

      If there is an insufficient quantity of CSF for both IgM capture ELISA and RT-PCR, testing priorities will be determined by the ordering physician.

      Patient information and laboratory data will be shared between NYSDOH and LHUs on a secure, integrated database on the HIN to facilitate case surveillance, and timely reporting of laboratory results back to the LHUs.

      In the event that acute specimens (obtained within eight days of illness onset) are negative by RT-PCR or EIA testing, laboratory diagnosis of WNV will require that a follow-up (convalescent) blood test be obtained at least 2 weeks after the acute specimen to evaluate for the presence of convalescent antibody to the virus. Since most patients will have been discharged from the hospital, LHUs will need to have the capacity to arrange for obtaining convalescent blood specimens on all suspect case-patients who have indeterminate or negative initial test results.

      LHUs will work with hospitals and physicians to encourage testing for only those patients that meet criteria for meningo-encephalitis only. Patients with milder illnesses (e.g., fever and headache, fever and rash, fever and lymphadenopathy) or no symptoms (e.g., persons with recent mosquito bite but no acute symptoms) do not need to be tested for WNV.

    4. System for Data Flow and Information Sharing for Human Surveillance.

      The physician will complete an initial case report (ICR) form on a patient with viral meningo-encephalitis (Appendix J). The physician will fax the form to the LHU where the case-patient resides and mail the form with the clinical specimen(s) to Wadsworth.

      Data from the ICR form will be entered into a secure, confidential site on the HIN by the LHU with jurisdiction in the case-patient's residence. Some LHUs (e.g., NYCDOH) may opt to enter data into a separate database and to arrange batch file exchanges with the HIN. LHUs that do not report communicable diseases through the HIN will mail the ICR form to the NYSDOH Statistical Unit for data entry on the HIN. The LHU will be responsible for obtaining and updating essential missing information (e.g., dates of onset and specimen collection).

      When NYSDOH receives the clinical specimen(s), the type of specimen and date received will be entered into the HIN. If data from the patient's ICR form has not been entered into the HIN by the LHU because the physician did not fax the form to the LHU, NYSDOH will either enter the data and notify the LHU, or fax the form to the LHU to do the data entry. If the residence of the patient is unknown, then the LHU with jurisdiction over the submitting hospital will contact the laboratory to obtain this information.

      NYSDOH will ensure that data on lab results are entered into the HIN site. The database section for laboratory results will have a field that will serve to notify the LHU that convalescent sera is needed to determine WNV case status if the initial test is non-diagnostic.

      NYSDOH will review the database regularly to look for errors, missing variables, duplications, etc.

      All new data on positive WNV human cases will be made available only to NYSDOH and the LHU involved, before sharing with other jurisdictions.

      NYSDOH will maintain up-to-date summary maps of all positive cases on a weekly basis.

  4. Roles and Responsibilities of the NYSDOH and LHU
    1. NYSDOH Roles and Responsibilities

      Develop surveillance materials (including template physician alerts, instructions for pecimen collection and submission, forms for requesting viral laboratory testing, case investigation forms).

      Prioritize WNV serologic and virologic testing on all suspect encephalitis cases, especially during the mosquito season from May through October.

      Ensure timely sharing of laboratory test results for WNV on a secure site on the HIN.

      Provide timely summary data on human surveillance activities in NYS.

    2. LHU Roles and Responsibilities

      All LHUs in NYS should implement enhanced passive surveillance in May 2000 and continue through October 2000.

      LHUs most affected by the 1999 outbreak (NYC; Nassau, Rockland, Suffolk and Westchester Counties) should implement one or more active surveillance protocols to complement enhanced passive surveillance programs.

      Coordinate all case surveillance activities, including tracking suspect case reports, ensuring submission of appropriate laboratory specimens to the NYSDOH, obtaining missing data (e.g., onset and collection dates, clinical syndrome) on the initial case report form and completing WNV case investigation forms for all positive cases.

      Develop the capacity to ensure that convalescent sera is obtained on all suspect encephalitis cases that test negative on acute specimens obtained within eight days of illness onset to definitively determine the presence or absence of WNV as the etiologic agent.

      Maintain and update HIN databases for case-patients in their jurisdiction to track local surveillance reports.

      Provide medical outreach and consultation to physicians in their jurisdictions regarding WNV encephalitis reporting and testing criteria.

Health Information Infrastructure

  1. Introduction

    Rapid electronic interchange of information between health officials at State and local health Departments and Federal Agencies is essential to rapid detection, response and abatement of disease outbreaks. NYSDOH, as part of a cooperative agreement with the CDC, has developed a Health Information Network (HIN) which is designed for this purpose.

  2. Objective

    Build on existing HIN infrastructure to implement the technology, processes, protocols and standards required to assure the most effective response possible to WNV by State and local health officials.

  3. Implementation Plan

    Standardize document interchange between NYSDOH and LHUs.

    Standardize information linkage, data sharing and data visualization between health jurisdictions and related State/Federal agencies.

    Enable secure electronic meetings and ad hoc file exchanges between NYSDOH and LHUs.

    Integrate electronic tracking, surveillance and lab reporting into central databases for humans, birds/mammals and mosquitoes.

    Insure adequate HIN access and training for those staff with WNV responsibilities at State and LHUs.

  4. Roles and Responsibilities

    Below is a summary of the tasks and lead agency for the major actions of the implementation plan. For details, see Appendix K.

Plan Actions Tasks Lead Agency(s)
1. Document Standards Develop Standards NYSDOH, NYCDOH, LHUs
  Survey LHUs for Input NYSDOH
  Revision and Implementation NYSDOH
2. Data Interchange Standards Develop Standards NYSDOH, NYCDOH, LHUs
  Survey LHUs for Input NYSDOH
  Revision and Implementation NYSDOH
3. Ad Hoc File Exchange Operational NYSDOH
  Training NYSDOH
a. Secure Electronic Meetings Operational NYSDOH
  Test Evaluation and Revision NYSDOH, NYCDOH, LHUs
  Training Initiated NYSDOH, NYCDOH, LHUs
4. Integrated Electronic Surveillance    
a. Human Case Surveillance Core Electronic Form NYSDOH
  Draft Electronic Form NYSDOH
  Electronic Lab Reporting NYSDOH
  Operational NYSDOH
  Training Initiated NYSDOH, NYCDOH, LHUs
b. Bird/Mammal Surveillance WNV Data Flow NYSDOH
  Draft WNV Form NYSDOH
  Electronic Lab Reporting NYSDOH
  Operational NYSDOH
  Training Initiated NYSDOH, NYCDOH, LHUs
c. Mosquito Surveillance WNV Data Flow NYSDOH
  Draft Electronic Form NYSDOH
  Electronic Lab Reporting NYSDOH
  Operational NYSDOH
  Training Initiated NYSDOH, NYCDOH, LHUs
5. Assess Access and Training Needs Develop Survey NYSDOH, NYCDOH, LHUs, NYSACHO
  Complete Survey NYSDOH
  Implement Access and Information Needs in Surveillance Systems NYSDOH
  Implement Training as Needed NYSDOH

Public Communication

  1. Introduction

    In September 1999, WNV, a mosquito-borne infection that can cause encephalitis, was found in NYS. Although the chances of a person getting encephalitis are small, there are some simple steps the public can take to reduce their risk even further. Therefore, enhanced public awareness and prevention education are two important strategies to address the potential return of WNV. These strategies can promote public cooperation in reducing man-made collections of polluted water in which Culex pipiens mosquitoes breed; help individuals reduce their risk of being bitten by mosquitoes; and educate health care providers about the virus, its prevention, and the diagnosis and treatment of human encephalitis.

  2. Objective

    Working collaboratively with other state agencies, officials and representatives of the health departments of New York City and Dutchess, Nassau, Orange, Putnam, Rockland, Suffolk, Sullivan, Ulster and Westchester counties, as well as community and environmental groups, the NYSDOH will mount an aggressive public health education campaign about WNV and other related arboviruses.

  3. Implementation Plan
    1. Specific Objectives

      Increase awareness among health professionals and the public of the potential risk for WNV infection and other arboviral diseases.

      Encourage health care providers to promptly report cases of human encephalitis.

      Improve knowledge among health care providers of the signs and symptoms of human encephalitis, and of appropriate treatments.

      Improve public knowledge of the sources and reservoirs of arboviral diseases(mosquitoes, birds and mammals).

      Encourage the elimination of Culex pipiens breeding sites (man-made collections of polluted water, such as stagnant backyard pools or bird baths, old tires, rain water barrels, etc.), as well as activities that will increase personal mosquito protection around the home, e.g., clean clogged rain gutters, install or repair screens). Culex pipiens, the common house mosquito, is the species most associated with transmission of WNV in NYS.

      Depending on the level of risk for WNV, as evidenced by bird and/or human infection, encourage the adoption of appropriate personal protection techniques (dress appropriately; consider using an insect repellent, but be informed about potential health effects; minimize outdoor activities between dusk and dawn).

    2. NYSDOH Activities

      Develop a health care provider education component that will include, but not be limited to: a professional education kit (containing a letter from the state health commissioner; fact sheets; treatment information; reporting instructions; samples of the public education materials and an order form); information on the DOH website; and news releases for professional journals and newsletters.

      Develop a public education component, in English, Spanish and other appropriate languages, that will include, but not be limited to: TV and radio spots; transit advertising; posters, flyers and paycheck stuffers; news and feature releases, B-roll video and fact sheets; information on the NYSDOH website; information through the Center for Environmental Health 800 line; print advertising for ethnic and community weeklies and Pennysavers; and CDC's "ANeato Mosquito" elementary school curriculum. All materials will be designed to be easily localized and duplicated by the participating LHUs.

      Develop specific messages for delivery on an "as-needed" basis in response to evidence of increasing risk for infection/death: Level 1 - anticipated but unsubstantiated risk; Level 2 - evidence of infection in birds; Level 3 - evidence of infection in humans; Level 4 - evidence of encephalitis-related serious illness and/or deaths in humans.

      Working collaboratively with other state agencies, officials and representatives of the health departments of New York City and Dutchess, Nassau, Orange, Putnam, Rockland, Suffolk, Sullivan, Ulster, and Westchester Counties, as well as community and environmental groups, the NYSDOH will mount an aggressive public health education campaign.

      1. Target Audiences

        Target audiences include residents and health care providers in the New York City metropolitan area and the Lower Hudson Valley. Outreach efforts will be conducted by the NYSDOH and counties, as appropriate. Specific audience segments include, but are not limited to:

        • Property owners (homeowners, businesses, municipalities) - NYSDOH and County outreach through State Emergency Management Office (SEMO) and County Emergency Management offices; mass media; other communication vehicles
        • Government officials and local opinion leaders - NYSDOH and County outreach through SEMO; County Emergency Management offices; mass media, other communication vehicles
        • Doctors- NYSDOH outreach through Medical Society of State of New York (MSSNY); other professional societies, as appropriate; direct written contact with providers
        • Nurses - NYSDOH outreach through State Education Department (SED)
        • Physician assistants - NYSDOH outreach through professional societies
        • Nurse practitioners - NYSDOH outreach through SED
        • Immune-suppressed individuals - NYSDOH outreach through its AIDS Institute
        • Media representatives (reporters, editors, public service directors, community service program producers, etc.) - NYSDOH and County outreach; press releases, PSAs, letters to the editor, editorial board meetings
        • Operators of elder care facilities - NYSDOH outreach through its Office of Continuing Care, NYS Office for the Aging; County outreach through local Offices for the Aging
        • School officials and School Nurse-Teachers/Health Educators/Athletic Directors - NYSDOH outreach through SED; County outreach as appropriate
        • Schoolchildren - NYSDOH outreach through SED; County outreach as appropriate
        • Youth organizations - NYSDOH outreach through Office of Children and Family Services, County outreach as appropriate
        • Operators of day care and preschool facilities - NYSDOH outreach through NYS Office of Children and Family Services (OCFA)
        • Operators of children's camps - NYSDOH outreach through its Center for Environmental Health (CEH); County outreach as appropriate
        • Campground operators, Resort operators - NYSDOH outreach through State Department of Environmental Conservation (DEC), Office of Parks Recreation and Historic Preservation (OPRHP), Empire State Economic Development Corporation (ESEDC); County outreach as appropriate
        • Beach, pool and parks and recreation managers - NYSDOH outreach through DEC, OPRHP; County outreach as appropriate
        • Hikers, campers, hunting and fishing enthusiasts, birders - NYSDOH outreach through DEC
        • Tourism offices, Chambers of Commerce - NYSDOH outreach through ESEDC
        • Environmental groups - NYSDOH outreach through CEH; DEC
        • Nature preserves, Botanical Gardens, Arboretums - NYSDOH outreach through DEC; County outreach as appropriate
        • Farmers - NYSDOH outreach through NYSAg&Mrkts ,Farm Bureau, NOFA
        • Migrant workers - NYSDOH outreach through CEH
        • Veterinarians - NYSDOH outreach through A&M
        • Outdoor workers, unions - NYSDOH outreach through State Department of Labor (DOL), State Department of Transportation (DOT)
        • Faith community - County outreach as appropriate
        • Government agencies - NYSDOH and County outreach as appropriate
        • Other audiences, as may be appropriate.
      2. Timeline

        The campaign will commence in the early spring, and will be designed to be maintained, and enhanced and expanded, reaching different segments of the target audiences, over the course of the mosquito breeding season (April-December 2000).

        Campaign Implementation, Maintenance & Expansion, Evaluation

        Pre-Season (April-May) Messages:

        • Your health department is prepared. Level 1 messages.
        • Mosquitoes carry disease.
        • You can prevent mosquitoes.
        • Find and eliminate mosquito breeding sites. Eliminating breeding sites will help lower your risk of contracting WNV and may help reduce the need for spraying later on.
        • Dead crows could be a sign of WNV. Be sure to report them to your local health department.

        Early Season (May-June) Messages:

        • Your health department is working to protect you. Level 1 and/or, possibly, Level 2 messages.
        • Mosquitoes are starting to appear.
        • Continue to find and eliminate mosquito breeding sites. Eliminating breeding sites will help lower your risk of contracting WNV and may help reduce the need for spraying later on.
        • There is no need to avoid outdoor activities just because mosquitoes are on the wing. If it is advisable to take precautions, health officials will provide that information.
        • As necessary, adopt personal protection techniques for yourself and family.
        • Recognize the signs and symptoms of encephalitis and seek medical care if needed.
        • Dead crows could be a sign of WNV. Be sure to report them to your LHU and follow their recommendations for disposal.
        • Recognize that other animals could be affected. Contact your veterinarian if you have a particular concern about a domestic or farm animal.

        Peak Season (July-September) Messages:

        • Your health department is working to protect you. Level 1 and/or Level 2, possibly Level 3 or Level 4 messages.
        • Mosquitoes are at their height.
        • Continue to find and eliminate mosquito breeding sites. Eliminating breeding sites will help lower your risk of contracting WNV and may help reduce the need for spraying later on.
        • There is no need to avoid outdoor activities just because mosquitoes are on the wing. If it is advisable to take precautions, health officials will provide that information.
        • Continue personal protection techniques.
        • The following types of individuals have the highest risk of serious illness from WNV: the elderly, children, people who have weak immune systems because of chronic disease, chemotherapy or because they are taking anti-rejection drugs following an organ transplant.
        • Recognize signs and symptoms of WNV and seek care as needed.
        • Dead crows could be a sign of WNV. Be sure to report them to your LHU and follow their recommendations for disposal.
        • Recognize that other animals could be affected. Contact your veterinarian if you have a particular concern about a domestic or farm animal.
        • If spraying becomes necessary, here are the facts you need (e.g. spraying schedules, chemical facts sheets, known health effects).

        Late Season (September-December) Messages:

        • Your health department is working to protect you. Level 1 and/or Level 2, possibly Level 3 or Level 4 messages.
        • Mosquitoes are still out there.
        • Continue to find and eliminate mosquito breeding sites. Eliminating breeding sites will help lower your risk of contracting WNV and may help reduce the need for spraying later on.
        • There is no need to avoid outdoor activities just because mosquitoes are on the wing. If it is advisable to take precautions, health officials will provide that information.
        • Continue personal protection techniques.
        • The following types of individuals have the greatest risk of infection from WNV: the elderly, children, people who have weak immune systems because of chronic disease, chemotherapy or because they are taking anti-rejection drugs following an organ transplant.
        • Recognize signs and symptoms and seek care as needed.
        • Dead crows could be a sign of WNV. Be sure to report them to your LHU and follow their recommendations for disposal.
        • Recognize that other animals could be affected. Contact your veterinarian if you have a particular concern about a domestic or farm animal.
        • If spraying becomes necessary, here are the facts you need (e.g. spraying schedules, chemical facts sheets, known health effects).

        Post Season (December-March) Message:

        • Prepare for next season by keeping property clear of mosquito breeding sites. Level 1 messages.
      3. Roles and responsibilities of the NYSDOH, LHUs, and other partners/organizations.
        1. NYSDOH Roles and Responsibilities:

          The NYSDOH, with guidance from members of the WNV Communications Workgroup, will produce the above educational materials and/or services and will purchase air time to broadcast appropriate educational messages on radio and TV stations within the outbreak areas. In addition to paid air time, Public Service Announcements (PSA) will be distributed. The NYSDOH will also assist LHUs with press announcements about new human, bird, animal and mosquito cases.

        2. LHU Roles and Responsibilities:

          As appropriate, LHUs will disseminate educational materials produced by the NYSDOH and to the extent possible, provide outreach to target audiences within their counties. LHU representatives will participate on the Public Communication Workgroup and will provide advice and guidance to NYSDOH staff through discussion, materials review and information exchange. LOCAL HEALTH DEPARTMENT representatives also will share materials they produce for use in their individual WNV education campaigns that may be adaptable for use by other counties. As per the legal requirements, localities should publicize spraying locations and times via print and broadcast media at least 24 hours in advance.

        3. Other Partners/Organizations Roles and Responsibilities:

          Representatives of the Citizens' Campaign for the Environment (CCE), Audubon Society, and Cornell University will assist the Public Communication Workgroup activities by providing advice and guidance relative to communication strategies; by participating in materials review, and, as appropriate, by helping to engage other members of the environmental advocate community in promoting individual efforts to reduce or eliminate breeding sites for the common household mosquito (Culex pipiens). To the extent possible, these partners also will assist in the dissemination of educational materials.

Response to Public Comments

An early draft of this plan was made available to the public on February 16, 2000, for comment. The Department received over 560 comments, many of which were incorporated into the final version of this plan. The following section summarizes many of the comments and the Department's response.

Comment 1
I have concerns about specific habitats in my neighborhood that I fear are creating an environment supporting mosquito development.
Response 1
These concerns need to be expressed to representatives of your LHU.

Comment 2
We are extremely concerned about our potential exposure to WNV and request the NYSDOH take very aggressive steps to prevent infected mosquito populations from reaching our families.
Response 2
The approach toward management of this virus and the mosquitoes that transmit it as described in this plan will serve to minimize risks of human exposure.

Comment 3
We are extremely opposed to any use of chemical insecticides.
Response 3
Every effort has been made in this plan to emphasize the use of more aggressive integrated pest management procedures for a disease vector, education measures, and mosquito habitat source reduction where practicable, as well as promoting the use of biological insecticides such as Bacillus sphaericus that target only mosquito larvae in the aquatic habitat. However, management of a mosquito-borne human pathogen with no effective treatment for human cases requires the consideration of chemical insecticides as a last resort if all other measures fail, in order to suppress the potentially infective mosquito population. It is preferable to target these operations to the mosquito larvae while they are in a limited environment, prior to their emergence as adults where they become air-borne and widely dispersed.

Comment 4
We were extremely upset with the insecticide applications that occurred last fall without any proper notification and demand that we be notified on time if similar operations occur this year.
Response 4
Unfortunately, under crisis conditions last fall, adverse weather interfered with published mosquito control operations. If conditions develop this year that require insecticide control operations, agencies are prepared to develop and implement the proper notification procedures as described in the plan. We may still face adverse weather conditions, but all feasible and practical efforts will be taken to provide updated information over the general public media.

Comment 5
How is a public health threat defined?
Response 5
For vector-borne diseases (diseases transmitted by insects or other arthropods like mosquitoes and ticks), a public health threat has been defined within New York's Code of Rules and Regulations (10 NYCRR 44). Part 44 identifies the specific thresholds of information that are required in order to reach a public health threat for disease agents that are transmitted by insects or arthropods in New York State.

Comment 6
How are LHUs reimbursed for their disease surveillance or control operations?
Response 6
In NYS Public Health Law, Article 611 identifies the extent of reimbursement that LHUs may request for their vector surveillance and/or control efforts. Reimbursement is applied to all statewide programs at a uniform rate and often changes on a year-to-year basis. Approved vector surveillance or control operations undertaken by an approved health agency may be reimbursed at that normal annual rate of reimbursement, or in emergency situations, at rates higher than the normal public health services rate.

Comment 7
We demand that more extensive monitoring of human health and environmental effects take place after any use of chemical insecticides.
Response 7
Staff from both the NYSDOH and the NYSDEC have begun working with the LHUs to establish a sensitive reporting and monitoring process for potential adverse human health reactions or environmental events.

Comment 8
Just how effective were the sprays last year in killing mosquitoes?
Response 8
Most good control efficacy studies require identical mosquito surveillance efforts in areas that are treated (by any intervention) and not treated (often referred to as the "control" area where the intervention is not applied). These surveillance efforts need to be conducted both prior to the intervention and after the intervention, in both the treatment and the control areas. Given the nature of the WNV outbreak and the interventions used to minimize human exposure to potentially infected adult mosquitoes, health agencies were unable to define areas that would be equivalent "non-treatment" areas. Some minimal pre- and post-spray mosquito counts were obtained, but reliable scientific efficacy information could not be obtained because of the lack of control data. Any intervention methods employed in this or subsequent years will have the benefit of new or enhanced ongoing surveillance data to help us determine how effective the chosen intervention method was.

Comment 9
We propose that the plan be reviewed on an annual basis by all affected parties.
Response 9
The agencies involved in developing this plan anticipate that this is a living document subject to change at any time in response to new scientific information. An on-going review of this document and modification as required is expected.

Comment 10
Several commentors stated that information in one appendix for the Prevention, Response and Control Chapter on the composition, toxicity and environmental fate of the mosquito adulticides did not contain all data available on these topics.
Response 10
The text and tables presented in the appendix were developed primarily for the purpose of allowing public health officials a means of comparing the relative toxicity and environmental fate properties of the pesticides that may be considered for mosquito control as part of the WNV Response Plan. The information is not intended to be a complete presentation of all data on the pesticides. While the appendix contains some information from the published literature, it largely comes from data developed for registration of pesticides by the U.S. Environmental Protection Agency (EPA). Because the EPA requires that specific tests be conducted and that these studies meet specific criteria, the use of such test results provides a relatively standard basis for comparison. The EPA continues to develop the database for some of the pesticides as part of their reregistration program. NYSDOH will modify the information in the appendix if such new data become available. NYSDOH will also continue to conduct searches of the published literature for relevant new study data.

Comment 11
The presentation and nature of the data in the appendix for the Prevention, Response and Control Chapter is too technical for the public to understand, and the information on these topics should be developed to educate lay persons.
Response 11
The NYSDOH agrees. As previously indicated, this appendix was not developed specifically for lay persons. However, previous postings on the NYSDOH website contained public information sheets for the various adulticides, and these fact sheets are being updated.

Comment 12
Numerous comments were submitted about insect repellents. Several commentors made statements that the public is not being given enough information about the proper use of and precautions for insect repellents, specifically the repellent DEET (N,N-diethyl-m-toluamide). Other commentors stated that NYSDOH should be advocating the use of "natural" repellents. Still others stated that EPA does not consider DEET to be "child safe" and that DEET cannot be applied to skin.
Response 12
The Plan refers to use of personal protection measures, including the use of the repellent DEET, as a means to prevent mosquito bites. Numerous repellent products are registered in NYS and most contain the active ingredients DEET or permethrin. DEET repellents come in many different concentrations ranging from about 5 percent to 100 percent. In general, the higher the concentration, the higher the protection, but the risk of adverse health effects also increases. DEET can be applied to exposed skin or to clothes. Unlike DEET repellents, permethrin repellents are for use on clothing only, not on skin, and contain very low concentrations of permethrin. Permethrin also kills ticks and insects that come in contact with it, whereas DEET only repels them.

Recognizing both the benefits and the risks of using repellents, NYSDOH has provided information to the public on several occasions to educate consumers about their proper use. An insect repellent flyer has been posted on the NYSDOH website (www.health.state.ny.us, search for "insect repellents") for some time. In addition, several NYSDOH press releases on WNV have also provided information on personal protection measures including the proper use of repellents. The NYSDOH has also developed two new fact sheets that discuss the proper selection and use of repellents. One fact sheet will be for public education purposes. The other is more technical and was developed for public health officials to use in responding to public inquiries. These will be available soon.

There are some so-called "natural" repellents that can be used as alternatives to DEET and permethrin. For the most part, these repellents contain either a mineral oil base or extracts from various plants. Because many of these products do not directly claim to be tick and insect repellents, they are not required to be registered as pesticides at the federal and state level. Consequently, studies that evaluate the toxicity and efficacy of these products and their constituents are, for the most part, very limited.

Based on statements from a number of commentors, there is some confusion on the registration status and labeling requirements for DEET products. By way of clarification, there are no restrictions on the maximum percent of DEET allowable in repellent products either at the federal or state level. Also, there are no restrictions against the use of DEET on skin, though the use of DEET on clothes rather than on skin is one way to reduce exposure to DEET when using such repellents.

The comments suggesting that the EPA considers DEET not to be "child safe" need to be clarified. The EPA Reregistration Eligibility Decision document (1998) states, as part of the discussion on labeling requirements, that "All direct or indirect claims of child safety must be removed from DEET end-use product labeling in order for those products to be eligible for reregistration". As discussed further in this document, this labeling requirement stems from EPA's position that child safety claims should be removed from all end-use products because such claims are "misleading and irreconcilable with the intended use and pesticidal ingredients of DEET products." The EPA does not prohibit the use of DEET products on children, nor do they believe that certain DEET repellents are inherently safer for children

Comment 13
Two commentors provided specific comments on the toxicology of malathion and the pyrethroids and provided partial references to support their statements. Several other commentors made similar statements as well, but did not provide corresponding references.
Response 13
The NYSDOH will obtain from the science literature (in those cases where they have not been obtained already) the specific references identified to determine their relevance to the WNV Response Plan. NYSDOH will also try to identify and obtain references that support some of the other statements submitted that did not specify references. After obtaining and evaluating additional study data, the Plan will be modified to address these issues if evaluation of the data indicates it is warranted.

Comment 14
The registrant of Fyfanon ULV (the malathion product used to control mosquitoes in 1999) submitted comments to indicate that the malathion content of this product ranges from 96 to 98 percent, with the current EPA approved label listing the nominal concentration to be 96.5 percent malathion. This commentor also stated that the acute oral LD50 value for 97.4 percent pure malathion is 5,500 milligrams per kilogram body weight in rats.
Response 14
The information in the Plan's appendix states that Fyfanon ULV contains 95 percent malathion and the acute oral rat LD50 values range from 1,522 to 1,945 milligrams per kilogram body weight. These values were based on the currently approved label in NYS and information available from EPA and open literature sources. It appears as though the registrant has slightly changed the formulation of the Fyfanon ULV product and has conducted some additional acute toxicity testing. The registrant did not, however, submit any new data. We have contacted the registrant to obtain this documentation and will modify the appendix if the data so warrant.

Comment 15
One commentor stated that the Prevention, Response and Control chapter does not mention the chemical isomalathion.
Response 15
The toxicological summaries were completed for the active ingredients alone. However, aside from malathion, the Fyfanon ULV product contains a number of compounds that are structurally related to malathion, including isomalathion. They are impurities formed during the manufacturing of malathion, a situation common to the production of many chemicals. Composition information from the registrant indicates that isomalathion in Fyfanon ULV is present at very low levels in the formulation, as is the case with the other impurities in this product. It should be noted, however, that the toxicological and environmental fate studies for pesticides are generally conducted on the technical grade material. This is the case for malathion. Consequently, the studies would also have evaluated the impurities.
Isomalathion can also form during the storage of malathion under certain conditions. NYSDOH and NYSDEC have contacted the registrant of Fyfanon ULV to obtain information on the storage stability of this product and whether compositional changes occur over time.

Comment 16
One commentor stated that the NYSDOH should consider the National Academy of Sciences (NAS) 1977 Drinking Water and Health volume, which the commentor states "is more accurate about malathion than your data."
Response 16
We reviewed the section on malathion in the 1977 NAS Drinking Water and Health document. It contains less toxicity data than does the appendix to the Prevention, Response and Control chapter. For example, the NAS document does not present any data on the genotoxicity and carcinogenicity of malathion. The Plan's appendix summarizes the results from such studies. In addition, our summary of the data for reproductive and developmental toxicity is more complete than that presented in the NAS document. Furthermore, the data that NAS presents is in agreement with our data summary. Examples of agreement in the two documents are the acute oral LD50 values for malathion and the oral reference dose or acceptable dietary intake values.

Comment 17
One commentor stated that the appendix to the Prevention, Response, and Control chapter does not mention synergism, not even in regards to piperonyl butoxide.
Response 17
The appendix states that piperonyl butoxide is present as a co-active ingredient in the Biomist, Scourge and Anvil products. Piperonyl butoxide is not an insecticide itself; it is in these formulations to enhance the insecticidal activity of the pyrethroid active ingredients. When piperonyl butoxide is used in this manner it is often referred to as a "synergist". Piperonyl butoxide increases pyrethroid toxicity to insects by inhibiting their ability to degrade the pyrethroids, thus making more insecticide available to cause toxicity.

A number of studies have evaluated the toxicity of piperonyl butoxide alone and the results of these studies are presented in the appendix. The extent to which piperonyl butoxide enhances the toxicity of pyrethroids in mammals can be examined in a limited way by comparing the acute toxicity of pyrethroids alone to that of the formulated products containing both pyrethroids and piperonyl butoxide. As an example, such data are available for permethrin and the product Biomist 4 + 12 ULV (very similar to the product Biomist 1.5 + 7.5 ULV) which contains permethrin and piperonyl butoxide; similarly, data are available for sumithrin and the product Anvil 10 + 10 ULV which contains sumithrin and piperonyl butoxide. The following table compares these data. All data in this table are from rat studies and definitions of the study types are in the appendix.

Pesticide Active Ingredient Formulated Product
Anvil 10 + 10 ULV    
  oral LD50 > 5,000 mg/kg > 5,000 mg/kg
  dermal LD50 > 2,000 mg/kg > 2,000 mg/kg
  inhalation LC50 > 2.1 mg/L 4.55 mg/L
Biomist 4 + 12 ULV    
  oral LD50 500 to > 4,000 > 5,000 mg/kg
  dermal LD50 > 4,000 > 2,000 mg/kg
  inhalation LC50 > 23.5 mg/L > 5.1 mg/L

As indicated by the data in the table, most studies did not identify the lethality endpoints (LD50, LC50) that the studies were designed to determine (these results are indicated by the "greater than" symbol before the numerical value). Studies are usually not conducted at doses higher than these values due to difficulties in administering the dose to test animals and because if no effects are observed at these doses, the material is not sufficiently toxic to warrant additional testing. Because most LD50 and LC50 values were not determined, it is not possible to determine whether the active ingredient alone or the formulated product is more toxic. Nevertheless, the data indicate that neither the active ingredient nor the formulated product is very acutely toxic, and the EPA classification for these studies would be either Toxicity Category III or Toxicity Category IV. The Toxicity Categories range from I for the most toxic compounds to Toxicity Category IV for the least toxic compounds.

Comment 18
One commentor questioned "Why would you spray Naled which contains CCl4 [carbon tetrachloride], a carcinogen, and methyl bromide, a highly toxic cpd [compound]?"
Response 18
Information on the formulation of the Dibrom Concentrate product does not indicate that naled contains either carbon tetrachloride or methyl bromide nor do we have information to indicate that they are degradates. The NYSDOH will continue to determine whether these compounds are present in technical naled or can occur from naled use and will modify the appendix if warranted.

Comment 19
One commentor questioned whether the preparers of the Plan were "aware that pyrethrins kill lobsters and fish."
Response 19
The mosquito adulticides Biomist, Scourge and Anvil 10 + 10 ULV, contain pyrethroids, not pyrethrins. Nevertheless, pyrethroids in general are considerably toxic to fish and other aquatic organisms and statements to this effect appear on both the Biomist and Scourge labels. The labels of all three products prohibit their use over water and thus mitigate direct exposure to fish, lobsters and other aquatic organisms. In addition, both permethrin and resmethrin have very low water solubilities and bind tightly to organic matter (e.g., in soil and on vegetation) which limit their likelihood of dissolving in water. Water solubility and organic carbon binding data are not available for sumithrin. However, it is expected that sumithrin has physicochemical properties similar to those of permethrin and resmethrin.

Comment 20
One commentor stated that resmethrin and sumithrin have been found in air conditioning filters in NYC four months after their use in 1999.
Response 20
The NYSDOH is willing to evaluate any such data the commentor may have, including the sampling procedures and analytical reports.

Comment 21
One commentor stated that "you must stop grossly misleading and highly inaccurate talk about everything breaking down quickly. Your own table of data states that malathion stays around for 147 days at pH5, yet you then state it breaks down quickly."
Response 21
Appendix C-3, Summary of Environmental Fate Information on Commonly Used Adulticides, states that "sumithrin breaks down relatively rapidly compared to the other synthetic pyrethroid mosquito adulticides (resmethrin and permethrin)" and that "the malathion half-lives from laboratory studies suggest that malathion breaks down more rapidly in water or soil than the synthetic pyrethroids (sumithrin, resmethrin and permethrin)." The Plan also notes in the Appendix that "the limited data available for piperonyl butoxide suggest that it is quite stable in the environment with essentially no degradation occurring as a result of hydrolysis, aqueous photolysis or soil photodegradation." In regard to malathion staying around for "147 days at pH5" (the actual pH is 6, not 5), this hydrolysis study finding is just one test result of a number of environmental fate studies on malathion. It is important to note that hydrolysis studies are designed to evaluate the process of hydrolysis alone (i.e., in sterile, distilled water in the absence of light) in isolation from other forces of degradation. Consequently, results from hydrolysis studies alone do not reflect degradation rates in the environment with the possible exception of degradation in some groundwaters. The environmental fate data overall indicate that malathion breaks down, as for example, by aqueous photolysis with a half-life of 41 days or in soil where the half-life is 4 to 6 days.

Appendix C-1 compares properties among mosquito adulticides. We will review the language to determine if any clarification is needed to emphasize that the statements are comparative.

Comment 22
The reference list presented in the Plan lists only four references for malathion.
Response 22
The four references listed, three of which are very recent, were presented to document the summary of the toxicity data, physiochemical properties and environmental characteristics of malathion, in Appendix C-1, Technical Information Tables for Mosquito Adulticides. These are comprehensive references which contain the information needed to prepare these tables. Numerous other studies and references were reviewed during the preparation of the Plan but were not cited if the data did not differ from that present in the cited references or were not directly relevant.

Comment 23
One commentor asked whether the Plan's developers had read " Dr. Blasiak's two studies that prove that malaoxon is genotoxic and this genotoxicity if [sic] irreversible?"
Response 23
Presumably the two references to which the commentor was referring are:

Blasiak, J. and J. Kowalik.. 1999. Protective action of sodium ascorbate against the DNA-damaging effect of malaoxon. Pesticide Biochemistry and Physiology. 65: 110-118.

Blasiak, J. et al. 1999. In vitro studies on the genotoxicity of the organophosphorus insecticide malathion and its two analogues. Mutation Research. 445: 275-283.

Both references report on a study conducted in vitro which suggests that the genotoxic effects (DNA damage) of malathion might result from this compound's metabolic biotransformation to malaoxon. This study showed that this damage was reversible, except for cells exposed to malaoxon at very high levels. From information presented by Balsiak and co-workers, it is estimated that the in vitro concentrations that produced these effects in the laboratory would be at least six times greater than the blood concentrations that agricultural workers wold have in extreme cases of over exposure.

Comment 24
One commentor questioned why the Plan did not make "reference to the Pakistan five deaths due to isomalathion?"
Response 24
The five deaths occurred in a large group of pesticide workers who were mixing and applying malathion by ground spray six days a week for mosquito control in Pakistan. These workers were heavily exposed to malathion and used extremely poor work practices (e.g., mixing material with their hands, wearing pesticide-saturated clothes for several days etc.). One death occurred in a sprayman who also ate food which had been sprayed. Given the nature of the exposures, this report is not relevant to the Prevention, Response and Control chapter.

Comment 25
One commentor stated that the Prevention, Response and Control chapter should indicate where people should go to get their cholinesterase levels tested.
Response 25
Cholinesterase testing related to pesticide exposure is clinically useful in two types of circumstances. First, tests are used for assessing acute, life-threatening pesticide poisoning to assist with treatment and follow-up. For example, the Poison Control Centers indicate that the tests should be used only when the dose and toxicity of the pesticide leads to symptoms clearly indicative of dramatic cholinesterase inhibition. Except for substantial accidental exposure (such as occupational exposure during mixing) or intentional ingestion, it is unlikely that exposures to malathion or naled would indicate the need for cholinesterase testing. Secondly, blood cholinesterase levels are also monitored among individuals who are routinely and repeatedly exposed to cholinesterase-inhibiting pesticides (e.g., pesticide applicators) to make sure that these individuals are not at risk of poisoning from the effects of cumulative exposure. The results of cholinesterase tests are highly variable among individuals and isolated tests on individuals would not help in defining the extent of exposure or health effects.

Comment 26
Some commentors noted that other states that have had mosquito problems, such as Florida and Texas, no longer spray pesticides for mosquito control. Why is NYS still spraying?
Response 26
NYS is focusing on a program that will prevent the mosquito that carries WNV from successfully breeding. The application of pesticides will only be used if absolutely necessary to control the spread of the disease. Mosquito surveillance has been under way for several months and efforts are currently underway to eliminate mosquito-breeding habitats. An extensive public education campaign called "Fight the Bite" was recently initiated by the NYSDOH Commissioner of Health to obtain the assistance of the public in eliminating mosquito-breeding areas around homes and buildings. Many not-for-profit organizations, such as the Boy Scouts, will be assisting in this effort as "Bite-Fighters" by going door-to-door in numerous communities to share information on ways to reduce breeding grounds. With these efforts in place, the need for spraying pesticides will be reduced and hopefully eliminated.

Comment 27
Organic farmers will be put out of business if you spray. Has this been considered?
Response 27
The focus of the WNV Response Plan is on preventing the spread of the disease through mosquito surveillance, habitat reduction and public education. The application of pesticides will only be used as a last resort to control the problem, should one arise. If spraying becomes necessary, the LHU will make this decision. If you are an organic farmer and have concerns about the spraying, if it becomes necessary, you should contact your LHU to share this information with them. If you are an organic home gardener, simple measures such as covering you garden when spraying is scheduled to take place will minimize the potential for pesticides to be applied to your garden areas.

Comment 28
Spraying may address the immediate problem of WNV, but what about the possibility that it will cause cancer 20 years from now?
Response 28
It is unlikely that the use of pesticides during the fall of 1999 to control mosquitoes carrying WNV, will cause cancer in people. This is based on animal studies done using a number of these pesticides. In most of these studies, laboratory animals were exposed to high doses of the pesticides over their entire lifetimes. Although these studies do have limitations, the evidence is insufficient to show that these pesticides will cause cancer in people because of the spraying.

Comment 29
The public must be involved and consulted in the decision to spray pesticides.
Response 29
The public is one of the most valuable partners in our effort to prevent the spread of WNV this year. Everyone can assist by eliminating breeding grounds that may exist near and around homes and buildings. This includes cleaning rain gutters, removing cans, barrels and other receptacles of water, changing water in bird baths at least every four days, and maintaining clean swimming pools or draining pool covers every few days.

The decision to apply pesticides to control adult mosquitoes will be made by the LHU, and pesticide application will take place only if necessary. Your LHU will be your source of the most up-to-date information about the status of the WNV Prevention Program and local telephone numbers and websites are available in most counties to provide this information. The health agencies are encouraging everyone to participate in the State's efforts to solve this problem.

Comment 30
Some commentors recommended that if pesticides are used, the NYSDOH should alert physicians to the symptoms of pesticide poisoning so that they are able to more effectively respond to their patients. It was also suggested that we use the Pesticide Poisoning Registry to track cases of health problems that might be due to the pesticide spraying.
Response 30
The NYSDOH is preparing a physician fact sheet for the commonly used pesticides which will be made available to physicians and to hospital emergency rooms. The NYSDOH will also monitor all reports received by the Pesticide Poisoning Registry. By law, physicians and health care facilities are required to report confirmed or suspected pesticide poisonings to the NYSDOH via a toll-free telephone call.

Comment 31
Are postmortems performed on dead birds to confirm cause of death?
Response 31
Postmortem exams are performed on a certain number of dead birds reported to the LHUs. These exams are performed by the NYSDEC's Wildlife Pathology Unit (WPU). Because crows are especially sensitive to WNV, they receive priority for evaluation and testing, but numerous other species are also tested. The WPU evaluates whether the bird died of numerous causes including trauma, poisoning, and infectious diseases like WNV.

Comment 32
Can it be determined if dead birds were infected acutely or if their deaths may have been caused by infection from last year?
Response 32
Evidence from the postmortem exam can help to determine whether the infection was recent (acute) or chronic, but cannot definitely answer that question. Other studies can provide evidence. Although investigations are continuing, to date there is no evidence of WNV in the United States prior to the summer of 1999.

Comment 33
I have maintained a bird feeder in my yard for years, but with hundreds of birds being infected with WNV, is it safe for my family if I continue to do so? Are we in danger of being infected by the birds that visit my yard and the feeder?
Response 33
There has been no indication that having birds come to a backyard feeder increases a homeowner's risk of being exposed to WNV. There has been no evidence of direct bird-to-person transmission. It is important that bird baths be kept clean since mosquitoes are attracted to standing stagnant water. Like any fecal material, bird droppings can carry many different types of infectious organisms, so it is always wise to avoid inhaling dust when tending to bird feeders, and to wear gloves and wash your hands well after handling feeders.

Comment 34
The plan does not adequately address worker protection issues for workers that implement mosquito control activities and workers that spend the workday outdoors.
Response 34
The plan has been modified to include specific reference to precautions that workers may choose to take in certain circumstances to reduce the risk of mosquito bites. The plan has also been modified to reference applicable New York State Department of Labor law and regulations. A fact sheet for workers will be developed.