The Centers for Disease Control and Prevention said it will test wastewater in parts of Michigan and Pennsylvania for poliovirus.
The CDC said it will conduct the wastewater testing months after a confirmed case of the virus was reported in New York.
“Wastewater testing will occur in certain counties with potentially low polio vaccination coverage, or counties with possible connections to the at-risk New York communities that are linked to a single case of paralytic polio,” the CDC said on Wednesday.
The CDC said they will target Oakland County, Michigan, and Philadelphia.
Wastewater testing allows the CDC to see if there are people in the community shedding the virus. It does not allow the CDC to identify a specific poliovirus case.
“Wastewater testing can be an important tool to help us understand if poliovirus may be circulating in communities in certain circumstances,” said Dr. José R. Romero, director of CDC’s National Center for Immunization and Respiratory Diseases. “Vaccination remains the best way to prevent another case of paralytic polio, and it is critically important that people get vaccinated to protect themselves, their families and their communities against this devastating disease.”
The Centers for Disease Control and Prevention said that most people infected with poliovirus, the virus that causes polio, do not experience symptoms. In severe cases of polio, it can cause permanent disability and death.
Nationally, 92% of children are fully vaccinated from polio by 24 months, the CDC said. The vaccine is considered 99% effective after three doses.
The CDC said that in the early 1950s, polio caused 13,000 to 20,000 paralytic cases a year. The development of vaccines in the mid-1950s dramatically reduced that number.
In 1960, there were 2,525 paralytic cases reported, and by 1965, just 61.
The CDC said that there has not been a single reported case of naturally spreading polio within the United States since 1979 until this year.