Overview of Enterovirus Infections
Enterovirus infections are caused by many different viruses.
Symptoms of enterovirus infections include fever, headache, respiratory illness, and sore throat and sometimes mouth sores or a rash.
Doctors base the diagnosis on symptoms and on examination of the skin and mouth.
Treatment of enterovirus infections is aimed at relieving symptoms.
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 among children.
Enteroviruses are spread (transmitted) in various ways. These viruses are spread by
Surfaces can become contaminated by saliva from an infected person or droplets expelled when an infected person sneezes or coughs.
The body's immune defenses stop many infections, and the result is few or no symptoms. Some people develop upper respiratory symptoms that resemble a common cold. A few people develop viral pneumonia.
Sometimes enteroviruses survive immune defenses and spread into the bloodstream, resulting in fever, headache, sore throat, and, at times, vomiting and diarrhea. People often refer to such illnesses as the "summer flu," although they are not influenza.
Some strains of enterovirus also cause 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 progresses 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.
The following diseases are caused almost exclusively by enteroviruses:
Enterovirus D68 respiratory infection
Meningitis is inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid space). Aseptic meningitis refers to meningitis that is caused by anything other than the bacteria that typically cause meningitis. This disease is most common among infants and children.
Aseptic meningitis that is caused by an enterovirus rarely causes a rash. Aseptic meningitis causes fever, severe headache, vomiting, a stiff neck, and sensitivity to light. Children may rarely also develop a viral brain infection (encephalitis).
Encephalitis is inflammation of the brain and can cause fever, vomiting, headache, confusion, weakness, seizures, and coma.
Enterovirus D68 causes a respiratory illness in children that usually resembles a cold. Children have a runny nose, cough, and generally feel ill, typically with only a slight fever if any. Some children, particularly those who have asthma, have more serious symptoms such as wheezing and difficulty breathing. Adults can be infected, but they tend to have few or no symptoms.
There was an increase in severe illnesses caused by enterovirus D68 in 2014 and 2018. Some of the infected children had severe respiratory distress. In addition, in some children the spinal cord was affected, causing weakness or paralysis of one of their arms or legs, and several children died. Doctors are not sure whether the enterovirus infection was the main cause of these complications or whether the virus merely happened to be present in children who also had other disorders.
Epidemic pleurodynia is most common among children. Epidemic pleurodynia affects the muscles of the chest, causing severe pain, often on one side of the lower chest or upper abdomen making breathing uncomfortable. Other common symptoms of epidemic pleurodynia include fever and often headache and a sore throat.
Symptoms usually lessen in 2 to 4 days but may return within a few days and continue or return for several weeks.
Hemorrhagic conjunctivitis involves inflammation of the eyes. The eyelids swell rapidly. This disease may lead to bleeding (hemorrhage) under the clear membrane that covers the white part of the eye (conjunctiva), causing the eye to become red. The infection may also affect the clear, curved layer in front of the pupil (the cornea), causing eye pain, tearing, and pain with exposure to bright light. Depending on which enterovirus causes the disease, people rarely develop a brief period of weakness or paralysis of their legs.
People usually recover in 1 to 2 weeks.
Herpangina most commonly affects infants and children. Children suddenly develop fever with a sore throat, headache, loss of appetite, and frequently neck pain. Infants may vomit. Within 2 days of the start of the disease, grayish bumps develop inside the mouth and throat. The bumps become painful sores, which heal in 1 to 7 days. Despite the name, this enteroviral disease has nothing to do with herpesvirus infection or the heart problem called angina.
Sometimes mothers pass on enteroviruses to their newborn during delivery. Usually, several days after birth, infected newborns suddenly develop a severe, generalized illness similar to sepsis. They have fever, are very sleepy, and have bleeding, and the virus can damage parts of many organs and tissues, causing multiple organ failure (including heart failure).
Newborns may recover within a few weeks, but death may occur, particularly if heart failure or other severe organ damage is present.
Myopericarditis is inflammation of the heart muscle (myocardium) and/or the sac that covers the heart (pericardium).
The heart infection may occur at any age, but most people are 20 to 39 years old. People may have chest pain, abnormal heart rhythms, or heart failure or may die suddenly. People usually recover completely, but some people develop a problem with the heart called dilated cardiomyopathy.
Newborns who are affected at birth (myocarditis neonatorum) have fever and heart failure. Heart failure causes difficulty breathing and poor feeding. Many infants die.