The first US polio case in more than a decade was found in vaccination-poor Rockland County, NY, where the virus has now been found in wastewater.
The first case of polio in nearly a decade was diagnosed in a young unvaccinated adult living in Rockland County, New York, approximately 2 weeks ago. The case was reported to the public by the New York State Department of Health (NYSDOH) on July 21, 2022.
On Monday NYSDOH reported that the polio virus was detectable in wastewater samples collected in Rockland a month before state health officials announced the confirmed case. According to the Centers for Disease Control and Prevention (CDC) the presence of the virus in wastewater suggests there may be more people in the community who are shedding the virus in stool. No new cases have been identified, however, and it is not yet clear whether the virus is actively spreading—in New York or elsewhere in the US.
The local wastewater assessment began immediately after the Rockland case was confirmed with state officials reviewing samples of sewage already collected to test for COVID-19. In collaboration with the CDC, it was determined that the virus found in Rockland is genetically linked to a strain in samples recently analyzed in Jerusalem, Israel and in London, said NYSDOH. That strain originated from a weakened virus that is used in oral polio vaccines no longer administered in the US. NY state health officials stress that this does not imply the infected Rockland residenthas a travel history to Israel or to England. Nor has the individual received an oral polio vaccine, the DOH said.
How the individual was exposed, health officials say, remains under investigation.
Polio is extremely contagious and can be transmitted even though an individual does not feel sick. The virus is often asymptomatic but may be associated with generalized flu-like symptoms such as a sore throat, fever, fatigue, and nausea, according to the CDC. Symptom latency, however, can be up to 30 days, a period during which the virus can be shed to others. In the small number of cases where the virus enters the nervous system, it can cause irreversible paralysis.
NY state and local health officials are opening vaccine clinics and urge anyone who is not vaccinated against polio to get inoculated immediately.
"Given how quickly polio can spread, now is the time for every adult, parent, and guardian to get themselves and their children vaccinated as soon as possible," said New York State Health Commissioner Mary T Bassett, MD, MPH, in the NYSDOH press release.
The infected resident, who experienced paralysis a month before state health officials confirmed the case, has been identified as a member of the Orthodox Jewish community in Rockland County, the New York Times reports. The same community, according to the Times, was at the center of a measles outbreak in 2018-2019, traced to relatively low vaccination rates among the highly devout members.
The DOH warns that unvaccinated New Yorkers who live, work, go to school in, or visit Rockland County are at the highest risk of exposure to the polio virus. Rockland County currently has a polio vaccination rate of 60.5% among 2-year-olds compared to the statewide average of 79.1%, according to the statement.
Inactivated polio vaccine (IPV) is the only polio vaccine that has been given in the US since 2000. US children are routinely vaccinated against polio with the inactivated vaccine with 4 recommended doses to be given at 2 months of age; at 4 months; at 6 to 18 months; and at age 4 through 6 years. Some states require only 3 doses. The vaccine, according to the CDC, protects 99% of children who get all the recommended doses.
According to the CDC’s most recent childhood vaccination data, about 93% of 2-year-olds had received at least 3 doses of polio vaccine.