The Chicago Department of Public Health (CDPH) announced that it is expanding its existing wastewater surveillance program to begin testing for poliovirus.
CDPH has begun testing to analyze water samples collected from area reclamation plants that serve the City of Chicago and surrounding Cook County suburbs. As part of this surveillance, wastewater samples will be routinely collected and processed for laboratory testing for poliovirus to see if poliovirus is present and understand if the type of poliovirus found is of concern.
While no case of paralytic polio has been identified in Chicago or Illinois at this time, CDPH is proactively building its local capacity to detect and respond to any potential case of polio.
CDPH’s current program routinely tests wastewater samples across the city of Chicago to monitor SARS-CoV-2 and influenza and provides monthly updates for the public on its website: https://www.chicago.gov/city/en/sites/covid-19/home/covid-19-wastewater-surveillance.html
Additional SARS-CoV-2 wastewater data for the greater Chicago area is available at https://iwss.uillinois.edu/.
In July 2022, a case of paralytic polio was identified in a New York State resident, and further wastewater testing detected poliovirus in water samples collected across multiple counties with low polio vaccination rates, suggesting likely local circulation of the virus in those community areas.
Wastewater data cannot be used to determine or identify who is infected or how many people or households are affected, but it can enhance other data and surveillance methods used to prevent polio. Not all potential detections will be cause for concern. However, if specific strains of poliovirus are found in communities that have low vaccination rates, it can spread among unvaccinated individuals, putting them at risk for becoming infected and developing polio.
“Polio has been eradicated in the U.S. since 1979; however, a recent case in 2022 in New York State highlights the importance of rapid detection to interrupt any new outbreaks and strengthen routine immunization, which is the best national defense against polio,” said CDPH Deputy Commissioner Massimo Pacilli.
Polio can lead to permanent paralysis of the arms and legs and can be fatal. While there is no cure for polio, it is preventable through safe and effective immunization. In the United States, the risk of getting polio is extremely low. Most people are vaccinated against polio during childhood, and this provides protection against serious illness, including paralytic polio.
Improving vaccination coverage, rapid reporting, and national case surveillance are the keys to preventing cases of paralytic polio. The complete recommended polio vaccination series is extremely effective in preventing paralytic polio, and the vaccine protects against severe disease in almost everyone who has received the recommended doses.
The new Chicago polio surveillance effort is a collaboration between CDPH and scientists from the University of Illinois Chicago, the Regional Innovative Public Health Laboratory at Rush University Medical Center, the University of Illinois System’s Discovery Partner Institute, the Illinois Department of Public Health, the Metropolitan Water Reclamation District of Greater Chicago, and the Centers for Disease Control and Prevention.