Statement by New York State Health Commissioner Antonia C. Novello, M.D. - West Nile Virus

Culex Pipiens Mosquitoes Collected From Fort Totten, Northeastern Queens

March 9, 2000 – I have promised New Yorkers that the State Health Department will keep them abreast of important information regarding the possibility of a return of West Nile virus to our State. That is why I want to stress that the announcement today by the federal Centers for Disease Control and Prevention (CDC) that three of nine pools of hibernating adult Culex pipiens mosquitoes collected from Fort Totten, in northeastern Queens, had low but detectable levels of West Nile viral RNA should not result in unnecessary concern on the part of New Yorkers.

The three mosquito pools in question were among 67 pools of Culex mosquitoes collected from various locations during the month of January in New York City under the direction of a State Health Department entomologist. As we had told you, we initiated the surveillance of hibernating mosquitoes as part of our continuing and comprehensive health planning to address the possibility that West Nile virus might reappear. Preliminary results regarding these pools were based on laboratory cultures, all of which were negative. This new identification, of parts of the West Nile virus genome, used a sophisticated method of molecular testing. Although it is an innovative diagnostic tool, it does not answer the question of whether the presence of West Nile viral RNA makes the mosquito capable of spreading West Nile infection.

The public health significance of the identification of West Nile viral RNA in overwintering mosquitoes remains uncertain, and, without a doubt, the findings reinforce the importance of the State's actions in formulating a comprehensive plan for West Nile virus prevention, response and control.

The State plan, which was developed in collaboration with New York City, county health departments and representatives of environmental groups, calls for an increased, regular collection and laboratory testing of mosquitoes, and enhanced surveillance to identify potentially infected birds and small mammals, as well as expedited reporting of suspect human cases. As a result of these efforts, health officials will know quickly if the virus has reappeared in a particular area. The improvements we are making to our health infrastructure, as well, will expedite laboratory test results and allow us to use electronic information systems to share essential data with affected counties and New York City to help them make fully informed decisions.

With our recent warmer weather, people may notice mosquitoes on the wing in some locations. With the information we have on hand today, New Yorkers need not avoid outdoor activities. There is no evidence that, to date, Culex pipiens mosquitoes – the species most associated with transmission of West Nile virus – are active. Culex species generally emerge much later in the year, when the hours of daylight increase. The virus must be repeatedly transferred between infected mosquitoes and animal reservoirs (usually birds) to increase the number of infected mosquitoes before it poses a risk to humans.

New Yorkers should be assured that protecting public health is a high priority of this Department. We will remain vigilant against West Nile virus and continue our comprehensive, collaborative, proactive and responsible approach to addressing this issue.

3/9/00–29 OPA