Test Your Knowledge

Enteroviruses cause some of the most common viral infections. Only common cold viruses cause more viral infections than enteroviruses. Each year, between 10 million and 15 million cases of symptomatic enterovirus infections are reported in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC). Enteroviruses are highly contagious.

These viruses derive their name from the fact that they usually begin their infection in the gastrointestinal tract, although they may not cause specific disease there. They are more likely to affect the central nervous system or upper respiratory tract.

Enteroviruses are made up of ribonucleic acid (RNA) and protein. Viruses are classified as either RNA viruses or deoxyribonucleic acid (DNA) viruses. An RNA virus must first turn its RNA into DNA and then insert itself into the host’s DNA. The viral genes are then copied many times, using the process the host cell would normally use to reproduce its own DNA.

In most cases, people who become infected with an enterovirus do not become ill. Those who do become sick often have relatively mild symptoms similar to those associated with a common cold or the flu. However, some patients may experience more severe illnesses. Some people infected with an enterovirus may go on to develop viral meningitis. In rare cases, an enterovirus infection can lead to illnesses that affect the heart (myocarditis) or brain (encephalitis). Other enterovirus infections may lead to paralysis. In newborns, enterovirus infections can replicate rapidly in certain organs and quickly become fatal.

However, in most cases, patients who become ill after an enterovirus infection do not experience long-term complications, especially if the illness is mild or if it involves viral meningitis. However, some patients who experience polio virus-related paralysis or encephalitis may have permanent health problems. Patients with myocarditis also may develop heart failure that requires long-term care. Scientists also believe that enterovirus infections may play a role in the development of juvenile-onset diabetes mellitus.