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 enterovirus infections, and the result is few or no symptoms. Some people develop upper respiratory symptoms that resemble a common cold Common Cold The common cold is a viral infection of the lining of the nose, sinuses, and throat. Many different viruses cause colds. Usually, colds are spread when a person's hands come in contact with... read more . A few people develop viral pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more .
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:
Polio Polio Polio is a highly contagious, sometimes fatal enterovirus infection that affects nerves and can cause permanent muscle weakness, paralysis, and other symptoms. Polio is caused by a virus and... read more and postpolio syndrome Postpolio Syndrome Postpolio syndrome is a condition of muscle fatigue and weakness that develops years or decades after a polio infection. Some people who have had polio develop postpolio syndrome years or decades... read more
Other diseases, such as aseptic meningitis Introduction to Meningitis 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). Meningitis can be... read more , encephalitis Encephalitis Encephalitis is inflammation of the brain that occurs when a virus directly infects the brain or when a virus, vaccine, or something else triggers inflammation. The spinal cord may also be involved... read more , myopericarditis Myocarditis Myocarditis is inflammation of the muscle tissue of the heart (myocardium) that causes tissue death. Myocarditis may be caused by many disorders, including infection, toxins and drugs that affect... read more , and hemorrhagic conjunctivitis Infectious Conjunctivitis Infectious conjunctivitis is inflammation of the conjunctiva usually caused by viruses or bacteria. Bacteria and viruses can infect the conjunctiva. Redness and tearing or discharge are common... read more , may be caused by enteroviruses or other organisms.
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 Viral Meningitis Viral 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) when it is caused... read more 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 Encephalitis is inflammation of the brain that occurs when a virus directly infects the brain or when a virus, vaccine, or something else triggers inflammation. The spinal cord may also be involved... read more ).
Encephalitis Encephalitis Encephalitis is inflammation of the brain that occurs when a virus directly infects the brain or when a virus, vaccine, or something else triggers inflammation. The spinal cord may also be involved... read more 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 Asthma in Children Asthma is a recurring inflammatory lung disorder in which certain stimuli (triggers) inflame the airways and cause them to temporarily narrow, resulting in difficulty breathing. Asthma triggers... read more , 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 Infectious Conjunctivitis Infectious conjunctivitis is inflammation of the conjunctiva usually caused by viruses or bacteria. Bacteria and viruses can infect the conjunctiva. Redness and tearing or discharge are common... read more involves inflammation of the eyes. The eyelids swell rapidly. This disease may lead to bleeding (hemorrhage Subconjunctival Hemorrhage Subconjunctival hemorrhages are small accumulations of blood beneath the conjunctiva (the membrane that lines the eyelid and covers the front of the eye). Sometimes the whole eye appears red... read more ) 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 Sepsis in Newborns Sepsis is a serious bodywide reaction to infection spread through the blood. Newborns with sepsis appear generally ill—they are listless, do not feed well, often have a gray color, and may have... read more . 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 Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more ).
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 Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more , or heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more or may die suddenly. People usually recover completely, but some people develop a problem with the heart called dilated cardiomyopathy Dilated Cardiomyopathy Dilated cardiomyopathy is a group of heart muscle disorders in which the ventricles (the two lower chambers of the heart) enlarge (dilate) but are not able to pump enough blood for the body’s... read more .
Newborns who are affected at birth (myocarditis neonatorum) have fever and heart failure. Heart failure causes difficulty breathing and poor feeding. Many infants die.