Poliomyelitis virus particle, computer illustration.
Katerina Kon | Scientific Photo Library | fake images
Polio was found in sewage samples taken from two counties outside of New York City, indicating the virus is spreading in the community, according to state health officials.
Wastewater samples taken from two different locations in Orange County during June and July tested positive for the virus, according to the New York State Department of Health.
The findings come after an unvaccinated adult in Rockland County contracted polio, became paralyzed and had to be hospitalized last month. Polio was later found in sewage samples from Rockland County. Rockland County is a neighbor of Orange County.
“These environmental findings, which further indicate possible community spread, in addition to the case of paralytic polio identified among a Rockland County resident, underscore the urgency for all New York adults and children to be vaccinated against polio, especially those in the New York metropolitan area, New York health officials said.
The strain of polio that the adult contracted in Rockland County suggests that the chain of transmission did not begin in the United States. The strain the individual contracted is used in the oral polio vaccine, which contains a mild version of the virus that can still replicate. This means that people who receive the oral vaccine can spread the virus to other people.
But the United States has not used the oral polio vaccine in more than 20 years. The US uses an inactivated polio vaccine that is given as a shot in the leg or arm. The vaccine uses a strain of virus that does not replicate, which means that people who receive the vaccine cannot infect other people.
The polio case in New York is genetically linked to the Rockland County sewage sample, as well as samples from the Jerusalem metropolitan area in Israel and London in the UK. UK health authorities declared a national incident in June after polio was detected in London sewage samples.
“New Yorkers should be aware that this does not imply that the individual case identified in Rockland County, New York, has a history of travel to Israel or the United Kingdom,” the New York state health department said.
No cases of polio have occurred in the US since 1979, and the nation has been considered polio-free ever since, according to the Centers for Disease Control and Prevention. Polio caused widespread fear in the 1940s, before vaccines were available. The virus disabled more than 35,000 people each year during that time, according to the CDC.
But a successful vaccination campaign in the 1950s and 1960s dramatically reduced the number of infections. Polio cases are still being reported in the US, but they are linked to travelers bringing the virus into the country. The case in Rockland County is the first time the US has confirmed an infection since 2013. New York state last confirmed an infection in 1990.