Enteroviral Infections
Enteroviral Infections: Common in Childhood
The enteroviruses include numerous strains of coxsackievirus, echovirus, enterovirus, and poliovirus. These viruses are responsible for illness in 10 to 30 million people each year in the United States, primarily in the summer and fall. Infections are highly contagious and typically affect many people in a community, sometimes reaching epidemic proportions. Enteroviral infections are most common in children, particularly those living in conditions of poor hygiene.
The infection begins when material contaminated with the virus is swallowed. The virus then reproduces in the digestive tract. The body's immune defenses stop many infections at this stage, and the result is few or no symptoms. Colds and upper respiratory infections are common outcomes of infection with enteroviruses. Sometimes, the virus survives and spreads into the bloodstream, resulting in fever, headache, sore throat, and, at times, vomiting. People often refer to such illnesses as the "summer flu," although they are not influenza.
Some strains of enterovirus also produce a generalized, nonitchy rash on the skin or sores inside the mouth. This type of illness is by far the most common enteroviral infection. Rarely, an enterovirus will progress from this stage to attack a particular organ. The virus can attack many different organs, and the symptoms and severity of disease depend on the specific organ infected. Several diseases are caused by enteroviruses:
- Hand-foot-and-mouth disease affects the skin and mucous membranes, causing painful sores to appear inside the mouth, on the hands and feet, and occasionally on the buttocks or genitals.
- Herpangina also affects the skin and mucous membranes, causing painful sores on the tongue and the back of the throat.
- Aseptic meningitis affects the membranes covering the brain and spinal cord (meninges), causing severe headache, stiff neck, and sensitivity to light.
- Encephalitis affects the brain, causing confusion, weakness, seizures, and coma.
- Paralytic poliomyelitis affects the nervous system, causing weakness of various muscles.
- Myocarditis affects the heart, causing weakness and shortness of breath with exertion.
- Epidemic pleurodynia (Bornholm disease) affects the muscles, causing severe intermittent pain in the wall of the lower chest (adults) or upper abdomen (children).
- Hemorrhagic conjunctivitis affects the eyes, causing painful, red, runny eyes; bleeding under the conjunctiva; and swollen eyelids.
Enteroviral infections usually resolve completely, but infections of the heart or central nervous system are occasionally fatal. There is no cure. Treatment is directed at relieving symptoms.