What are the symptoms of polio?

An American who contracted the virus has suffered paralysis as a result

For the first time in nearly a decade, polio has been found infecting an American.

Though the virus was effectively eradicated in the 1970s following the success of Jonas Salk's vaccine — which has been developed around 20 years prior — an unvaccinated young adult was infected a little over a month ago.

The Associated Press reports that the individual, who lives in Rockland County, New York, discovered they had symptoms about a month ago, and has since developed paralysis.

What are polio symptoms?

Like many other viruses, most people who become infected with polio don't actually exhibit symptoms. According to the US Centers for Disease Control and Prevention, about a quarter of individuals who become infected will experience flu-like symptoms including sore throat, fever, tiredness, nausea, head ache and stomach pain.

Those symptoms generally last two to five days before fading away.

Around one to five out of every 1,000 infected people will suffer the more severe symptoms of polio, which include paresthesia, (the feeling of pins and needles in the legs) meningitis (an infection that covers the spinal cord and brain) and paralysis.

The CDC considers paralysis polio's most sever symptom as it can lead to death. The virus eventually weakens the muscles the body needs in order to continue breathing,.

Wasn't polio eradicated? How is it spreading?

Polio was eradicated from the US in 1979. While the virus remained endemic in other regions of the globe, it was pushed to near total global eradication by the mid 2010s. Currently only Afghanistan and Pakistan have endemic polio.

Health officials believe the individual who became infected had not taken their polio vaccine when they were younger. They believe a portion of the virus that had been used in a vaccine traveled from a vaccinated person to the unvaccinated person.

Brown University pandemic researcher Dr Jennifer Nuzzo told the AP that the bizarre infection should serve as a wakeup call to the world.

“This isn’t normal. We don’t want to see this,” she said. “If you’re vaccinated, it’s not something you need to worry about. But if you haven’t gotten your kids vaccinated, it’s really important that you make sure they’re up to date.”

Investigators said the individual is no longer contagious, but are curious how they came into contact with a live virus specimen.

Two types of polio vaccines exist. The US and many other nations use a shot that incorporates in inactivated version of the virus in order to prompt the body's immune response.

Some countries use a shot that contains a weakened live virus. Though typically safe, there have been rare instances in which the live virus mutated into new forms capable of outbreaks.

Unlike the Covid-19 vaccines, which were swept up in domestic culture war rhetoric, the overwhelming number of American children — around 93 per cent — have received at least three doses of their polio vaccines.