Genetic analysis of two wastewater samples from Canada that were positive for vaccine-derived poliovirus type 2 (VDPV2) are linked to a cVDPV2 case from New York's Rockland County and to other environmental samples found in New York wastewater.
In a Jan 19 epidemiological update on polio, the Pan American Health Organization (PAHO) said the genetic testing on the two Canadian samples was conducted by the US Centers for Disease Control and Prevention (CDC).
Earlier this month, PAHO detailed the two positive environmental samples from Canada, which were collected in late August in areas closely linked to communities in New York where the viruses were found between May and December. Canada has not reported any human cases.
In 2022, similar environmental findings were reported from London and Jerusalem.
Five African nations report more cases
In other polio developments, five African countries reported more polio cases last week, according to the latest update from the Global Polio Eradication Initiative (GPEI). The cases were from Cameroon, Chad, the Democratic Republic of the Congo (DRC), Nigeria, and Somalia.
All of the countries reported more cVDPV2 cases, but the DRC also reported several more cVDPV1 cases. All were added to the country totals for 2022. The single new case that Cameroon reported marked its second case for 2022.