What to know about polio and the first US case in nearly 10 years

Health authorities say the case may have originated outside of the United States.

Polio under a microscope
This 1964 microscope image made available by the US Centers for Disease Control and Prevention shows damage from the polio virus to human spinal cord tissue [File: AP]

The first case of polio in the United States in nearly 10 years has been identified in the state of New York in a young unvaccinated man.

The New York State Health Department said in a statement on Thursday the case in Rockland County may have originated outside of the US.

The person is no longer deemed contagious, but investigators are trying to figure out how the infection occurred and whether others were exposed. Officials also told healthcare providers to be on the lookout for more cases and urged people in the area who are not vaccinated to get the shot.

According to a report by The Washington Post newspaper, the patient has been discharged and living at his parents’ home with his wife. He can stand but is having difficulty walking.

Here is what to know about the disease.

What is polio?

  • According to the Centers for Disease Control and Prevention (CDC), polio is a disabling and life-threatening disease caused by the poliovirus.
  • The virus spreads from person to person and is highly infectious. A severe case of polio involves nerve injury that can lead to paralysis, breathing difficulties and even death.
  • The spread can occur through the faecal-oral route or contaminated water or food.
  • According to the World Health Organization (WHO), the virus enters the body through the mouth and multiplies in the intestine.
  • The disease mainly affects children under five years of age.

What are the symptoms?

  • The WHO says that up to 90 percent of those infected will experience no or mild symptoms, and the disease often goes unrecognised.
  • For others, initial symptoms can include fever, fatigue, headache, vomiting and pain in the limbs.
  • These symptoms could last two to five days and then go away.
  • However, a smaller proportion of people with the infection could develop symptoms that could affect the brain and spinal cord.
  • According to the WHO, paralysis can occur within a few hours of infection. Of those paralysed, 5 to 10 percent die when they are not able to move their breathing muscles.

Can polio be cured?

  • The WHO says there is no cure for polio but it can be prevented with vaccines.
  • Treatments for polio focus on limiting and alleviating the symptoms. Physical therapy can aid in stimulating the muscles, while drugs can also help them relax. These treatments could improve mobility but cannot reverse permanent polio paralysis.
  • However, two vaccines are available: oral polio and inactivated polio. Vaccinations against the disease means it is rare in most parts of the world.

How long does the vaccine protect you?

  • The CDC says it is unclear how long people who received the vaccine will be immune, but they “are most likely protected for many years after a complete series of [vaccines]”.

Wasn’t polio eradicated in the US and elsewhere?

  • Since 1979, no cases of polio have originated in the US, but occurred in incoming travellers.
  • According to US authorities, the more recent polio cases in the country were not wild strains;  the last-known one registered by the CDC was in 2013.
  • The US saw a polio outbreak in the 1940s, which disabled more than 35,000 people each year, according to the CDC.
  • The WHO says that of the three strains of poliovirus, Type Two was eradicated in 1999, and no cases of Type Three have been found since a reported case in Nigeria in 2012. As of 2020, Type One affects only two countries: Pakistan and Afghanistan.
  • Globally, cases have decreased by 99 percent since 1988 when polio was endemic, and 350,000 cases were recorded globally. In 2021, there were six reported cases, according to the WHO.
Source: Al Jazeera