Polio Investigation General Overview

About the Investigation

On July 18, 2022, CDC was notified about a case of polio, in New York state in an unvaccinated patient who presented to an emergency room with lower limb weakness with fever.

The New York State Department of Health is actively investigating the situation and will provide regular updates on any developments as they learn more. Right now, there are no other cases identified.

The NY State Health Department, with CDC’s support, is working with the affected communities, to assess any potential risk and help put in place prevention measures, like vaccination clinics, to keep people from getting sick.

CDC uses patient samples from the New York state health department to do further poliovirus testing consisting of an attempt to isolate virus using cell culture, considered the gold standard, and real-time polymerase chain reaction (rt PCR) assays, as well as genome sequencing to detect and characterize any poliovirus present.

CDC confirmed the presence of poliovirus at several wastewater sampling sites in New York and is currently working with New York to test for poliovirus in wastewater samples.

Wastewater Testing

  • Wastewater data can help us better understand what communities might be at the highest risk and increase vaccination efforts for those most vulnerable.
  • Wastewater samples are untreated wastewater taken from waste treatment plants; this does not mean that poliovirus is being found in open drains or potable water.

NYSDOH wastewater surveillance: Polio Wastewater Surveillance (ny.gov)

CDC Polio Laboratories

Since the inception of the global initiative in 1988, the CDC Polio Laboratory has helped WHO build the Global Polio Laboratory Network (GPLN) – a three-tier system of 145 laboratories worldwide – and serves as a WHO Global Specialized Reference Laboratory. 

CDC’s laboratories provide critical diagnostic services, conduct genomic sequencing of polioviruses, and develop novel techniques and products that help to advance the global effort to eradicate polio. In 2018, this included the first phase of development of a new oral polio vaccine. These efforts are aimed at reducing the risk of vaccine associated paralytic paralysis (VAPP) and circulating vaccine derived polioviruses (cVDPV). Other new laboratory procedures are helping countries overcome specific operational challenges, enabling more rapid detection of poliovirus, and allowing for faster response to importations or spread of virus. 

Learn more: Poliovirus Laboratory Testing

National Poliovirus Response

CDC All-Hazards Plan Executive Summary 

This is a base plan that would be implemented regardless of the type of event: 1) breach in containment, 2) importation, or 3) unknown source. The base plan contains the common actions for any response concerning a Polio case in the U.S. and three branches for specific circumstances. Branches include:  

  • Branch 1 – A breach in containment at a Poliovirus Essential Facility (PEF) in the United States: This would likely be the result of a known event (e.g., a spill) and would necessitate monitoring of exposed individual(s) but may not result in an actual case of poliomyelitis.
  • Branch 2 – Importation: A case of poliomyelitis identified in an individual in the United States that is linked with international travel to a country with an outbreak of wild or vaccine-derived poliovirus.
  • Branch 3 – Unknown source case(s): A case (or cases) of poliomyelitis identified in an individual in the United States OR a stool specimen positive for poliovirus in a case that is not linked with international travel or any other known connection to a poliovirus associated facility or exposure to live poliovirus vaccine, and would require more extensive investigation to determine the source. Note that since poliovirus has been eliminated in the United States, a single case of polio is considered an outbreak and would be investigated thoroughly. An individual with primary immunodeficiency, AFP, and a stool specimen positive for poliovirus1 would require investigation under this branch, but would not require an IMS activation. Multiple cases meeting this description would also fall under Branch 3.
Page last reviewed: August 19, 2022