Poliomyelitis (polio) is a highly infectious virus that has no cure and can cause paralysis or even death. After nearly 40 years of no sustained poliovirus transmission in the United States (US), a case of paralytic polio was confirmed in New York, prompting a rapid public health response by local, state and national authorities.
The World Health Organization declared the US polio-free in 1994. But on July 21, 2022, public health officials announced a case of paralytic polio in an immunocompetent but unvaccinated young adult in Rockland County, New York. The patient had not recently traveled internationally; alarmingly, this suggested that the patient had acquired the disease through community transmission of the poliovirus. This recently-identified case spurred a rapid public health response.
The Centers for Disease Control and Prevention (CDC), New York State Department of Health, and local authorities issued an advisory to increase healthcare provider awareness, enhanced surveillance for potentially infected persons, tested wastewater from Rockland and surrounding counties, evaluated vaccination coverage in the patient’s community, provided inactivated polio vaccine (IPV) to county immunization providers, and implemented vaccination clinics throughout Rockland County.
Genetically similar poliovirus (that is, poliovirus carrying similar genomic characteristics to that of the poliovirus isolated from the patient) was detected in at least 20 wastewater samples collected from New York’s Rockland and Orange counties in May, June, and July 2022 (including samples originally collected for coronavirus surveillance), as well as in New York City sewage. Since this provides evidence of community circulation of the poliovirus, after these results were obtained in August 2022, additional outreach to local providers and syndromic surveillance were launched in order to detect symptomatic nonparalytic infection as well as asymptomatic infection.
According to the New York State Immunization Information System, the 3-dose inactivated poliovirus vaccine (IPV) vaccination coverage among infants and children aged <24 months living in Rockland County had declined from 67.0% in July 2020 to 60.3% in August 2022 (possibly due to the disruption of routine vaccination services during the COVID-19 pandemic), with the rate as low as 37.3% in one zip code. This compares with a New York statewide average of about 79% and a nationwide average of 92.7% for infants born in 2017 and 2018. The low vaccination coverage rate in Rockland County indicates that the community is at risk for additional cases of paralytic polio and, therefore, on July 22, 2022, the Rockland County Department of Health launched a countywide catch-up vaccination effort.
This recent case of polio has brought renewed attention to the importance of maintaining high vaccination rates against this potentially devastating disease.
This article was edited by Sarah McNamara and Emi Krishnamurthy.