The U.S. Centers for Disease Control and Prevention (CDC) said on Wednesday it will expand wastewater testing for poliovirus in areas with low vaccination coverage or counties that are linked to a case in New York reported in July.

Detection of poliovirus in sewage or wastewater indicates someone in the community is shedding the virus.

The strategic use of testing, which is expected to last at least four months once initiated, can help determine if poliovirus is present in other parts of the country. The CDC said this can be used to target vaccination efforts and rapidly improve local polio vaccination coverage if needed.

In July, the first confirmed case of polio in the United States in nearly a decade turned up in an adult in Rockland County in New York.

Polio can cause irreversible paralysis in some cases, but it can be prevented by a vaccine. While there is no known cure, three doses of the vaccine provide at least 99% protection.

The Michigan Department of Health and Human Services and the Philadelphia Department of Public Health are among the first locations to explore plans to start collecting wastewater samples in specific communities for analysis at CDC's polio laboratory, the health agency said.