Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP) Health officials in New York have once again detected poliovirus in wastewater from Rockland County, where a case of paralytic polio occurred last summer. Wastewater samples from Rockland and several nearby counties were positive for poliovirus for months after the initial case was reported in July, suggesting widespread circulation of the virus in the region. So far this year, officials have only detected poliovirus in one sample, which was collected from Rockland in February.