In New York, one person suffered paralysis weeks ago because of a polio infection in Rockland County, north of the city. Wastewater samples collected in June in both Rockland and adjacent Orange County were found to contain the virus.
Most people infected with polio have no symptoms but can still give the virus to others for days or weeks. Vaccination offers strong protection and authorities urged people who haven’t gotten the shots to seek one immediately.
Based on past outbreaks, it is possible that hundreds of people in the state have gotten polio and don’t know it, officials said.
Polio was once one of the nation’s most feared diseases, with annual outbreaks causing thousands of cases of paralysis. The disease mostly affects children.
Vaccines became available starting in 1955, and a national vaccination campaign cut the annual number of U.S. cases to less than 100 in the 1960s and fewer than 10 in the 1970s, according to the Centers for Disease Control and Prevention.
A small percentage of people who polio suffer paralysis. The disease is fatal for between 5-10% of those paralyzed.
All schoolchildren in New York are required to have a polio vaccine, but Rockland and Orange counties are both known as centers of vaccine resistance.