New York's Poliovirus Detection Continues in June 2025

The United States has been included in the World Health Organization's latest notice regarding a Public Health Emergency of International Concern due to polio detections.

As a result, the country is subject to Temporary Recommendations issued by the International Health Regulations Emergency Committee on Polio Eradication.

Moreover, the U.S. Centers for Disease Control and Prevention (CDC) has recently confirmed that circulating poliovirus remains a risk in 41 countries. In response, several U.S. states have ramped up their detection efforts.

For example, the New York State Department of Health (NYSDOH) recently published an advisory to guide the reporting and submission of specimens for persons with suspected acute flaccid myelitis (AFM).

AFM is a rare but serious paralytic condition characterized by the rapid onset of flaccid weakness in one or more limbs. Similar to polio, AFM affects the nervous system, specifically the gray matter of the spinal cord, causing muscles and reflexes in the body to weaken.

Paralytic polio and AFM can have similar clinical presentations and occur with similar seasonality, occurring between August and November.

During 2024, New York State reported six AFM cases, bringing the total to 33 cases since surveillance began in 2014. More than 90% of cases have occurred in children under 10 years old.

The NYSDOH states that no single pathogen has been consistently detected in patients with AFM, although data suggest that enteroviruses play a significant role in the epidemiology of AFM. People who tested positive for enterovirus EV-D68 typically had more severe AFM illness.

Furthermore, poliomyelitis should be considered in the differential diagnosis for patients with acute flaccid weakness if they are unvaccinated or under-vaccinated for polio, if their vaccine history is unknown, or if they are immunocompromised.

During the summer of 2022, a confirmed case of paralytic polio was identified in an unvaccinated resident of Rockland County, NY. 

This case was the first known case of paralytic polio in the U.S. since 2013 and the first documented instance of community transmission of poliovirus in the U.S. since 2005.

In 2022, sequencing analysis confirmed the presence of poliovirus in a total of 100 positive samples of concern in Sullivan, Rockland, Orange, Nassau, and New York City.

These environmental findings provide evidence that the unvaccinated individual in Rockland County with paralytic polio contracted the virus through local transmission. 

The NYSDOH states that New Yorkers should be aware that these environmental findings do not indicate that the individual in Rockland County was the source of the transmission.

And advises clinicians who suspect AFM to collect the following specimens as early in the course of illness as possible.

Additionally, the inactivated poliovirus vaccine (IPV), the only polio vaccine administered in the U.S., protects approximately 99% of individuals who receive all recommended doses.

Moreover, a booster dose may be recommended by a healthcare provider for international travelers visiting areas with confirmed poliovirus detections in 2025.