'This isn’t normal': What to know about New York polio case, a rarity in the US

The U.S. has reported its first case of polio in nearly a decade, in a young unvaccinated adult who had not recently traveled outside the country.

The case, which presented with paralysis symptoms, has put health officials in Rockland County, New York, on high alert. Officials say getting vaccinated is vital to protect against potential outbreaks.

►The New York patient appears to have a vaccine-derived strain of the virus, possibly transmitted from someone who received a type of vaccine not offered in the U.S.

►The patient did not recently travel outside the country, and developed symptoms about a month ago.

►The person is no longer considered contagious. Officials are trying to figure out how the patient was infected.

Here's what to know about polio:

Isn't polio eliminated in the US?

Polio was declared eliminated in the U.S. in 1979, meaning that there was no longer year-round transmission of the poliovirus in the country. A case of polio has not originated in the U.S. since then. Travelers occasionally bring it with them; the last known case was in an infant who had traveled from India in 2013.

Is the polio vaccine still given?

Children in the U.S. should receive four doses of the polio vaccine — three doses within their first 18 months and a booster between ages 4 and 6. Since there is no cure for polio, vaccines are the only protection against it.

Should I be worried about polio?

Not if you and your loved ones are vaccinated, according to a pandemic researcher.

The new case discovered in New York should serve as a wake-up call for anyone unvaccinated or who didn't complete their series, said Jennifer Nuzzo, a Brown University researcher.

“This isn’t normal. We don’t want to see this,” Nuzzo 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.”

How long does the vaccine last?

According to the CDC, it isn't known how long vaccine protection lasts, but it likely lasts "many years." Three doses is considered 99% to 100% effective.

Can the polio vaccine make you sick?

There are two types of polio vaccines given throughout the world. In the United States since 2000, you can only be vaccinated via injection with an inactivated poliovirus vaccine, so there is no risk of developing polio from the vaccine.

The oral poliovirus vaccine is still used in many other countries. It contains a weakened live virus that is given to children as drops in the mouth. In rare cases, the weakened virus can mutate and become capable of transmission.

What are the symptoms of polio?

Poliomyelitis, or polio, is caused by the poliovirus. While only those who experience paralysis have the polio disease, the poliovirus can infect people without causing symptoms at all, according to the CDC. About a quarter of those infected will show flu-like symptoms that usually resolve on their own in a few days.

A smaller fraction of people who get infected with poliovirus will have much more serious symptoms. Some may experience paresthesia, or the sensation of pins and needles in the legs. About 1 in 25 people infected with poliovirus develop meningitis.

The most serious symptom is paralysis, occurring in about one out of every 200 people infected. It mainly affects children under 5 years old and can be permanent, disabling and even lead to death because the virus affects the muscles that control breathing.

How contagious is polio?

Poliovirus is very contagious, the CDC says. It enters the body through the mouth and lives in the throat and intestines, and is most commonly spread through contact with tiny particles of an infected person's feces in food and water. It can also spread through droplets from a person's mouth, but that is less common.

What is post-polio syndrome?

Some people who had and recovered from polio can be affected decades later with what is called post-polio syndrome. Its symptoms include muscle weakness and atrophy, fatigue and joint pain. It is not contagious.

Contributing: The Associated Press

This article originally appeared on USA TODAY: New York polio case: What to know about polio symptoms, vaccines