Polio Circulating Since April In The Hudson Valley: CDC

HUDSON VALLEY, NY — Polio has been circulating in the region since April, a month earlier than previously known, federal health authorities reported Tuesday.

In its Morbidity and Mortality Weekly Report, researchers with the Centers for Disease Control and Prevention said as of Aug. 10, a total of 260 wastewater samples from treatment plants in Rockland and Orange counties — including samples originally collected for COVID-19 surveillance — were tested for poliovirus. Among these samples, 21 yielded positive poliovirus test results, including 13 from Rockland County and eight from Orange County.

The 20 wastewater samples collected during May, June, and July were genetically linked to virus from the patient; one additional sample, from April in Orange County, was sequenced as also poliovirus type 2, but the sequence was incomplete, precluding assessment of genetic linkage to the case.

The CDC revealed more information about the lone case of paralytic polio. The patient, a Rockland County resident, went to a hospital emergency department in June after five days of low-grade fever, neck stiffness, back and abdominal pain, constipation, and 2 days of weakness in his legs. He was hospitalized with a suspected case of acute flaccid myelitis or AFM. Eleven days later, he was discharged to a rehabilitation facility. Testing was extensive, looking for enteroviruses and human parechovirus, respiratory pathogens and encephalitic viruses; then sequencing of a stool specimen by the New York State Department of Health's laboratory identified poliovirus type 2.

"Based on the typical incubation period for paralytic polio, the presumed period of exposure occurred 7 to 21 days before the onset of paralysis," the CDC researchers wrote. "Epidemiologic investigation revealed that the patient attended a large gathering 8 days before symptom onset and had not traveled internationally during the presumed exposure period. No other notable or known potential exposures were identified."

As of Aug. 10, medical investigators have tested three people who met clinical criteria and who lived in or traveled to specific counties or neighborhoods in New York or had international travel since May 1; however, tests were negative for poliovirus, the CDC said.

Health providers and officials are on the lookout for signs of nonparalytic infection, characterized by mild symptoms such as low-grade fever and sore throat, or more severe symptoms (e.g., aseptic meningitis) and asymptomatic infection.

This is only the second community transmission of poliovirus identified in the United States since 1979, the researchers said.

Because the patient had not traveled internationally during the potential exposure period, detection of VDPV2 in the patient’s stool samples indicates a chain of transmission within the United States originating with a person who received a type 2-containing oral polio vaccine (OPV) abroad; OPV was removed from the routine immunization schedule in the United States in 2000. Genome sequence comparisons have identified a link to vaccine-related type 2 polioviruses recently detected in wastewater in Israel and the United Kingdom.

As of Aug. 10, no additional poliomyelitis cases have been identified, although the detection of poliovirus genetically linked to virus from the patient in wastewater specimens from two counties in New York State over the course of months indicates community transmission and ongoing risk for anyone who isn't vaccinated, the CDC said.