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. Two samples from the county taken during March were negative. Before the detection in February, the last positive sample from the region was found in mid-December in Orange County, just north of Rockland. The last positive detection in Rockland was in October.

Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP )

Health officials in New York are ramping up efforts to boost polio vaccination rates in local children as yet more poliovirus has surfaced in sewage sampling.

On Friday, August 12, New York state and New York City health officials announced that poliovirus had been detected for the first time in New York City sewage , suggesting local circulation of the virus.

The finding follows similar detections in sewage sampling in nearby Rockland and Orange counties during May, June, and July. On July 21 , health officials in Rockland county reported a case of paralytic polio in a young, unvaccinated male resident who had not recently traveled out of the country. The man's symptoms began in June.