State health officials say a young adult in New York has become the first US resident to contract polio in nearly a decade.

The unnamed patient in Rockland Country is said to have developed paralysis from the virus but is no longer contagious.

“State health officials say a young adult in New York has become the first US resident to contract polio in nearly a decade.“

According to officials, the person was unvaccinated and was presumably exposed to someone who had received the weaker live virus vaccine.

The highly contagious virus's last known case was reported in 2013.

The disease, once widely feared across the country, was eradicated mainly by a countrywide immunisation campaign that started in the 1950s.

Annual cases rapidly decreased from more than 100 in the 1960s to less than ten in the 1970s, and by 1979, the US had been proclaimed polio-free.

Since then, international visitors have imported sporadic polio instances into the nation.

The virus, which mainly affects children, can result in death, permanent impairment, paralysis, and muscle weakness.

Americans are generally vaccinated with a three- or four-dose regimen that begins at two months old. According to vaccination figures from the US Centers for Disease Control and Prevention, about ninety-three per cent of toddlers have received at least three doses of the polio jab vaccine.

But whereas the United States and other countries use jabs which contain an inactivated version of the virus, some countries orally provide a vaccine that uses the virus in a weakened live form.

That weakened virus may, in rare circumstances, mutate and risk an outbreak.

Similarly, to the patient in Rockland County, the last identified polio case in the US - a seven-month-old child who moved to the state of Texas from India in 2013 - was vaccine-derived.