A young unvaccinated American, the first American case in nearly ten years, has contracted polio, announced Thursday July 21 the health authorities of the State of New York. A resident of Rockland County, 30 miles north of Manhattan, the patient first experienced symptoms about a month ago and now suffers from partial paralysis. He has not traveled recently and would therefore have been infected in the United States.
According to a statement, his case indicates “a chain of transmission from an individual who received the oral polio vaccine (OPV)”, a viral vector vaccine which has not been used in the United States since 2000. However, someone could have received it abroad, before infecting other unvaccinated people with its attenuated viral strain.
New York health officials have asked doctors to monitor for possible new cases and urged county residents who are not vaccinated to do so. The last known case of polio in the United States was in 2013, according to the Centers for Disease Control and Prevention (CDC). A 7-month-old child who had just moved from India to the United States was diagnosed in San Antonio, Texas.
A disease that almost disappeared, which reappears
The World Health Organization warned last month that a type of poliovirus derived from oral polio vaccine – which in rare cases can cause infection in others but not in the person vaccinated – had been detected in London sewage samples. It can cause severe illness and paralysis in unvaccinated people.
Polio, a highly infectious viral disease that largely affects children under the age of 5, has been virtually eradicated worldwide. Cases have fallen by 99% since 1988, when polio was still endemic in 125 countries and 350,000 cases were recorded.
Contaminations declined sharply in the late 1950s and early 1960s in the United States, with the development of a vaccine. The last natural infection to have occurred in the territory dates from 1979.