Wastewater Surveillance

Why is NYSDOH conducting wastewater surveillance?

Following the identification of polio among a Rockland County resident, NYSDOH launched wastewater surveillance to check for signs of the virus, one of many detection tools that can help assess the spread of polio in communities. This process includes collecting retrospectively stored samples from Rockland County and, to be as extensive as possible, available samples from throughout the State.

What are the results of the wastewater findings so far?

Wastewater surveillance is an active, ongoing effort that NYSDOH is leading in partnership with local, national, and global public health authorities.

As of September 23, 2022, sequencing analysis by the Centers for Disease Control and Prevention (CDC) confirmed the presence of poliovirus in a total of 69 positive samples of concern:

  • Of the 69 positive samples of concern, 62 samples have been found to be genetically linked to the individual case of paralytic polio among a Rockland County resident.
  • Of the 62 samples, 37 samples were collected in Rockland County, 16 samples were collected in Orange County, 8 samples were collected in Sullivan County, and 1 sample was collected in Nassau County.
  • Of the 37 samples identified in Rockland County, 2 were collected in May, 3 were collected in June, 9 were collected in July, 21 were collected in August, and 2 were collected in September.
  • Of the 16 samples identified in Orange County, 2 were collected in June, 5 were collected in July, and 6 in August, and 3 were collected in September.
  • Of the 8 samples identified in Sullivan County, 2 were collected in July, 5 were collected in August, and 1 was collected in September.
  • The sample identified in Nassau County was collected in August.
  • 7 positive samples of concern, 1 collected in April from Orange County and 2 collected in June and 4 collected in July from New York City have also been identified. While at this time, these samples have not been genetically linked to the individual case in Rockland County, sequencing analysis characterizes these samples as either a vaccine-derived poliovirus (1, collected in New York City in July) or variants of the revertant polio Sabin type 2 poliovirus (6, 3 collected in July and 2 collected in June in New York City; 1 collected in April in Orange County). Both of these types of polioviruses can cause illness, including paralysis, in humans.

NYSDOH will continue its wastewater surveillance efforts in partnership with CDC, and communicate openly with New Yorkers as more information is available.

What do these results mean for New Yorkers?

These environmental findings provide evidence that the unvaccinated individual Rockland County resident with paralytic polio contracted the virus through local—not abroad or international—transmission and raise concerns about the potential for community spread of poliovirus that can cause paralysis in these communities. This underscores the urgency of every adult and child, particularly those in the greater New York metropolitan area, getting immunized and staying up to date with their polio immunization schedule.

New Yorkers should know that these environmental findings do not indicate that the individual in Rockland County was the source of the transmission, and case investigation into the origin of the virus is ongoing.

How can I learn more about wastewater surveillance happening in New York and around the world?

New Yorkers can learn more about New York State's wastewater surveillance programing here. More information about the work of the Global Polio Eradication Initiative (GPEI) and the Global Polio Laboratory Network (GPLN)—which includes the World Health Organization (WHO) and CDC—is available here.