What Are Enteroviruses? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Medically Reviewed
Enteroviruses, a group of viruses that cause a variety of infections, usually only lead to mild symptoms, such as a common cold. But in some cases — especially in young children or people with compromised immune systems — serious complications can develop.

Traditionally, enteroviruses were classified into four subgroups: polioviruses, coxsackievirus A, coxsackievirus B, and echoviruses.

In 2019, genetic studies led to the reclassification of 15 species of the enterovirus genus into enterovirus species A–L and rhinovirus species A–C, with multiple subtypes (aka “serotypes”).

Members of the enterovirus genus mutate and recombine easily within species, so hybrid and variant enteroviruses continue to be identified.

Because polio infection is complex and has been mostly eradicated worldwide due to widespread vaccination, this article will discuss non-polio enteroviruses.

Signs and Symptoms of Non-Polio Enteroviruses

Often, people infected with non-polio enteroviruses have no symptoms, or they have only mild illness, like the common cold. Common signs of mild illness may include:

Sometimes enterovirus infections can also cause:

  • Viral conjunctivitis
  • Hand, foot, and mouth disease
  • Viral meningitis (infection of the covering of the spinal cord and/or brain)
  • Viral encephalitis (infection of the brain)
  • Myocarditis (infection of the heart)
  • Pericarditis (infection of the sac around the heart)
  • Acute flaccid paralysis (a sudden onset of weakness in one or more arms or legs)
  • Inflammatory muscle disease (slow, progressive muscle weakness)
Infants and people with weakened immune systems are at greater risk of having these more serious complications.

Causes and Risk Factors of Non-Polio Enterovirus Infections

Infections with non-polio enteroviruses are common in the United States during summer and fall.

One of the biggest risk factors for infection is being an infant, child or adolescent, because most adults have been previously infected and have acquired immunity to enteroviruses.

For reasons that aren’t clear at this time, infections from an enterovirus subtype called D68 have been increasingly causing severe respiratory illnesses, as well as related muscle inflammation and weakness, over the past decade.


How Are Non-Polio Enteroviruses Diagnosed?

Infection with non-polio enteroviruses is confirmed by:

  • A genetic test like a polymerase chain reaction (PCR) test, or
  • Isolating the virus in cell culture and then testing with PCR to identify the virus
Samples can be collected from stool, rectal swabs, respiratory specimens (including the throat), blood, cerebrospinal fluid (CSF) or from the fluid drainage of blisters.

Duration of Enterovirus Infections

Most enterovirus infections cause only mild symptoms, which last about a week, and the virus leaves no lasting effects.

But severe infections can lead to long-term complications (see Complications, below).

Treatment and Medication Options for Non-Polio Enterovirus Infections

As with most viruses, treatment for enterovirus infections is aimed at helping to relieve the symptoms — for instance, drinking enough water to stay hydrated and taking over-the-counter cold medicine.

Severe infections, which cause serious complications, may require hospitalization.

Currently no medications exist that kill enteroviruses. Because they are viruses, antibiotics are ineffective against them.

Prevention of Non-Polio Enterovirus Infections

There is no vaccine to protect against non-polio enteroviruses.

The best way to prevent the spread of enteroviruses is to stay home when sick and to regularly wash hands for at least 20 seconds with soap and water. Good hand hygiene is especially important after using the toilet, changing diapers, or having physical contact with people who are sick.

Regularly cleaning and disinfecting frequently touched surfaces can also help to prevent the spread of enteroviruses. In addition, avoid sharing cups and utensils and wear a mask in public, especially if you or others are at high risk for serious illness.

Complications of Non-Polio Enterovirus Infections

Enteroviruses are varied and can impact different people in different ways. Some patients may get better at home, while others require hospitalization.

In cases of mild illness with fever or sore throat, children can get dehydrated. If an enterovirus causes blisters on the skin, skin infections may develop if the blisters are not kept clean.

More serious complications include severe respiratory problems or even paralysis and death.

People who develop myocarditis as a result of an enterovirus infection may have heart failure and need long-term care.

In rare cases, newborns infected with a non-polio enterovirus may develop sepsis, which can lead to tissue damage, organ failure, and death.

According to the CDC, non-polio enterovirus infections may play a role in the development of type 1 diabetes in children.

Research and Statistics: Who Gets Enterovirus Infections?

Non-polio enteroviruses cause 10 to 15 million infections in the United States each year and tens of thousands of hospitalizations. The people most vulnerable to severe illness are newborns and people with compromised immune systems.

Related Conditions of Non-Polio Enterovirus Infections

Hand, Foot, and Mouth Disease (HFMD)

Hand, foot, and mouth disease is common in children younger than 5, and it often spreads in schools or day-care centers. The condition is not usually considered very serious, but it is extremely contagious.

Symptoms of HFMD can include fever, sore throat, mouth sores, and a flat, red skin rash that shows up on the palms of the hands and soles of the feet. The rash can sometimes blister and show up on the knees, elbows, buttocks, or genital area. The virus can be found in the fluid of the blister and the scab itself, so the affected areas should be kept clean, and uninfected people should avoid touching them.

HFMD usually causes mild symptoms for 7 to 10 days, but parents may want to contact a healthcare provider if their child is not drinking enough to stay hydrated, if symptoms are severe or last more than 10 days, if the child has a weakened immune system, or if he or she is younger than 6 months old.

HFMD is frequently caused by the enteroviruses known as coxsackievirus A16, coxsackievirus A6, and enterovirus 71 (EV-71).

HFMD is not the same as foot-and-mouth disease, which is a disease that infects livestock.

Enterovirus D68

Doctors warn that enterovirus D68 (EV-D68) can cause particularly dangerous respiratory symptoms in people with asthma. If you are caring for a child with asthma who is sick with EV-D68, it’s important to follow their asthma action plan and to have their asthma medications available.

Anyone with respiratory illness should contact their doctor if they’re having difficulty breathing or if their symptoms are getting worse. Seek immediate medical attention if you or your child develops any of these symptoms following a respiratory illness:

  • Arm or leg weakness
  • Pain in the neck, back, arms, or legs
  • Difficulty swallowing or slurred speech
  • Difficulty moving the eyes or drooping eyelids
  • Facial droop or weakness

Enterovirus A71 (EV-A71)

Infection with EV-A71 can have mild symptoms (such as with HFMD) or no symptoms at all. Rarely, infection can lead to severe neurological illnesses like meningitis, encephalitis (swelling of the brain and spinal cord), or a kind of paralyzing illness called acute flaccid myelitis (AFM).

There have been rare cases documented where infection of the central nervous system with EV-A71 led to encephalitis of the brain stem and heart and respiratory failure.

Resources We Love

Centers for Disease Control and Prevention

The CDC’s website has a wealth of up-to-date info on non-polio enteroviruses, including what symptoms and complications they may cause, how to prevent the spread of infection, and a section on outbreaks and surveillance.

HealthyChildren.org

Infants and children with asthma have a greater risk of developing breathing problems and complications from enterovirus infections, so it's important that parents access trusted information on the topic. HealthyChildren.org, from the American Academy of Pediatrics, offers just that.

Editorial Sources and Fact-Checking

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