The 6 most common polio symptoms, from flu-like headaches to muscle pain

• New York City health officials reported traces of the polio virus in sewage water.
• Most people who get polio will not have visible symptoms, but the disease can cause paralysis in a small portion of infected people.

New York City health officials found traces of polio, a disease the US eliminated in 1979, in the wastewater on August 12.

The city and public health experts are urging people who aren't vaccinated against polio to get shot as soon as possible. People who were vaccinated as children likely do not need a booster shot because a four-dose vaccine series in childhood should last into adulthood, experts told Insider.

However, for unvaccinated or partially vaccinated people, "there is simply nothing more essential" than getting a vaccine — especially for kids — Dr. Ashwin Vasan, New York City's health commissioner, said in the statement. "Please choose now to get the vaccine," Vasan said.

The polio vaccine is up to 99-100% effective at preventing polio, according to the Centers for Disease Control and Prevention.

If somebody does contract the virus, most will not experience symptoms, but can lead to paralysis and lifelong disability in a minority of people.

Here's how to spot the signs of a polio infection:

Polio symptoms include fever, fatigue, and muscle pain

People contract polio by eating food or drinking water contaminated with the virus, according to the CDC. The virus is released into wastewater through the feces of infected individuals.

The disease can also spread through droplets from a sneeze or cough of an infected person. Getting stool or cough droplets from an infected person on your hands and touching your mouth can pass the virus to you.

The CDC states most people infected with polio will not have visible symptoms. One in four infected people will have flu-like symptoms that include:

• Sore throat;
• Headaches;
• Fever;
• Nausea;
• Fatigue;
• Stomach pain.

Celebrities like Alan Alda and Joni Mitchell who contracted polio as children before the vaccine was available said they felt intense muscle pain. In mild cases, symptoms typically last two to five days and then go away on their own.

In rare cases, polio can lead to paralysis and death

A small proportion of infected people — anywhere between one in 200 or one in 2,000 — will suffer serious symptoms effecting the brain and spinal cord, per the CDC.

The most serious symptom from polio is paralysis, or when a person cannot move parts of their body. Paralysis, as well as muscle weakness, can impair the legs, arms, or both.

People who experience paralysis from polio tend to have mild symptoms from nonparalytic polio at first, according to Mayo Clinic. The symptoms become more severe within a week.

Paralysis from polio can lead to lifelong disability or death. Children who seem to fully recover from polio can develop muscle pain, weakness, and paralysis 15 to 40 years later. Forty percent of people who survive polio suffer from delayed symptoms, also called "post-polio syndrome" — including Joni Mitchell, who described it feeling like "mind-numbing fatigue."

There is no cure for polio, but pain relief and physical therapy can help

Polio does not have a cure, and can only be prevented through highly-effective vaccines. Widespread vaccination eliminated the disease in the US.

Pain relievers can treat people with mild to severe muscle pain, while moderate exercise in the form of physical therapy can prevent muscle deformaties, per the Mayo Clinic. People whose breathing muscles become weak from polio may need ventilators, or machines that moves air in and out of your lungs.

The CDC states physical or occupational therapy started when infected early in a person with polio could improve arm or leg weakness. Antispasmodic drugs can relax the muscles and improve mobility, per the World Health Organization.