Health officials say polio was detected in four wastewater samples out of Sullivan County.

Two samples collected in July and another two collected in August are "genetically-linked to the case of paralytic polio previously identified in Rockland," according to the Department of Health.

All of the samples are considered "samples of concern," which means there is a risk of paralysis with this particular type of the virus.

The samples started being taken following the identification of the virus in an unvaccinated Rockland County individual in July.