Doctors across the U.S. have seen an increase among children of a respiratory virus that can cause polio-like muscle weakness.

In most cases, enterovirus D68 (EV-D68) causes a respiratory illness with mild symptoms. It can, however, result in a condition called acute flaccid myelitis (AFM) that can cause inflammation of the spinal cord. Those suffering from AFM can have trouble moving their arms while others experience muscle weakness. In severe cases, it can lead to respiratory failure or life-threatening neurologic complications.

The condition has several similarities to polio, although there is no vaccine for AFM.

According to an alert issued by the Centers for Disease Control and Prevention last week, pediatric hospitalizations are on the rise among patients with severe respiratory illness who tested positive for rhinovirus (RV) and/or enterovirus (EV). Some of the patients have also tested positive for EV-D68—and hospital sites are reporting a higher proportion of EV-D68 patients compared to previous years.

This isn’t the first time EV-D68 has caused problems. In 2014, an outbreak of enterovirus D68 was reported in multiple states, including Indiana. The outbreak involved nearly 1,400 people, although an undercount is very likely because many who experienced mild symptoms didn’t get tested.

Increased activity was also reported in 2016 and 2018, with lower circulation in 2020 likely due to COVID-19 mitigation measures.

Between July 2022 and August 2022, the number of detected EV-D68 cases was greater than the period from the three previous years (2019, 2020 and 2021). While the CDC hasn’t seen increased reports of AFM, an increase in AFM cases generally follows an increase in EV-D68 cases, the agency said.

The CDC alert asks providers to consider EV-D68 as a possible cause of respiratory illnesses among children and warns of a potential increase in cases in the weeks to come. Common symptoms for EV-D68 include cough, shortness of breath and wheezing. Fever is present in about half of known cases.

“On rare occasions, EV-D68 may cause AFM,” the CDC noted in its alert. “This rare but serious neurologic condition primarily affects children and typically presents with sudden limb weakness.”

According to the CDC, signs of AFM include:

  • 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

The agency noted that there are no available vaccines or specific treatments.

Infants, children and teenagers are most likely to get infected. Those who suffer from asthma may be at greater risk for severe cases of EV-D68.

The CDC urges the public to follow typical prevention measures:

  • Wash your hands often with soap and water for 20 seconds
  • Avoid touching your eyes, nose, and mouth with unwashed hands
  • Avoid close contact such as kissing, hugging, and sharing cups or eating utensils with people who are sick, and when you are sick
  • Cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your hands
  • Clean and disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.
  • Stay home when you are sick
  • Consider wearing a mask around other people if you have respiratory symptoms
  • Contact a healthcare provider immediately if you or your child has trouble breathing or has a sudden onset of limb weakness
  • Ensure you or your child are following an up-to-date asthma action plan if you or your child have asthma.
  • Stay up-to-date with all recommended vaccines