Enterovirus infections often have no symptoms, especially in adults. In people who do have symptoms, they are usually mild, resembling the common cold. Some people experience an illness more like the flu. Symptoms of an enterovirus infection may include:

Runny nose, sneezing, coughSore throatBody and muscle achesVomitingFeverConjunctivitis (also known as pink eye or Madras eye)Non-itchy rash on the skinSores on the mucous membranes, such as blisters inside the mouth

While most cases of enterovirus get better with rest and normal at-home care, in some people the illness can become very serious and require immediate medical attention. You should especially watch out for severe illness in infants and people with weak immune systems. Precautions should be taken for children with asthma or other lung problems, too, because they are more likely than others to develop serious breathing problems. More severe symptoms may include:

Difficulty breathingChest painWheezingBlue lips

Serious but less common complications can include the central nervous system and heart. It’s possible for the virus to infect the brain (causing encephalitis) or inflame the membranes that envelop the spinal cord and brain (causing meningitis), which may have a broad range of neurological symptoms. The virus can also inflame the sac around the heart (causing pericarditis), or even infect the heart muscle (causing myocarditis). Symptoms may include:

FatigueRapid heartbeatChest painShortness of breathSwelling in the feet, ankles, or legs

Symptoms in Children

Symptoms of enterovirus infection tend to be more severe in children than in adults, but most children can still be treated with supportive care at home. However, parents should seek immediate medical treatment for children who develop any of the following respiratory symptoms:

Difficulty breathingChest painWheezingBlue lips

Enterovirus D68 (EV-D68), which caused a nationwide outbreak of severe respiratory illness in 2014, was notable for causing these symptoms in some children, particularly those with asthma or other lung conditions. It’s also important to seek medical help for anyone who develops neurological symptoms, such as:

Facial droopingMuscle weaknessParalysisSevere headacheSeizures

In the 2014 outbreak, a small number of children who tested positive for EV-D68 developed these symptoms, although it was not absolutely certain they were caused by the virus.

Enterovirus Diagnosis

When doctors don’t know the diagnosis of a patient who has severe enterovirus-like symptoms, they might do a test to identify the disease and find out how to treat it. The test may entail taking a nasal or throat swab, collecting a stool sample, or doing a spinal tap. There are antiviral medications that can be used to help treat severe cases of many types of enterovirus infections. However, they were not effective against the EV-D68 enterovirus that caused the 2014 outbreak. Instead, diagnostic tests of nasal and throat swabs were used mainly to help public health officials track the spread of the virus.