A virus that enters the body through the gastrointestinal tract and thrives there, often moving on to attack the nervous system. The polioviruses are enteroviruses.
Enterovirus is a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Enteroviruses are named by their transmission-route through the intestine (enteric meaning intestinal).
Infections with enteroviruses are common in the United States during summer and fall. During that time in 2014, the United States experienced a nationwide outbreak of EV-D68 associated with severe respiratory illness. A total of 1,153 cases were confirmed in 49 states and the District of Columbia.
Almost all confirmed cases were among children, many of whom had asthma or a history of wheezing. CDC can’t predict whether EV-D68 will be a common type of enterovirus to cause sickness in future seasons because a mix of different enterovirus types circulates every year, and different types can be common in different years. But so far EV-D68 cases in years since 2014 have been reported more sporadically, which is considered typical.
Enteroviruses are small viruses that are made of ribonucleic acid (RNA) and protein. In addition to the three different polioviruses, there are a number of non-polio enteroviruses that can cause disease in humans, including the Coxsackieviruses (Coxsackie A viruses and Coxsackie B viruses), echoviruses, and other enteroviruses.
Enteroviruses can be found in the respiratory secretions (for example, saliva, sputum, or nasal mucus) and stool of an infected person. Other people may become infected by direct contact with secretions from an infected person or by contact with contaminated surfaces or objects, such as a drinking glass or telephone. Parents, teachers, and child-care-center workers may also become infected by contamination of the hands with stool from an infected infant or toddler during diaper changes.
Enteroviruses are a group of viruses that cause a number of infectious illnesses which are usually mild. However, if they infect the central nervous system, they can cause serious illness. The two most common ones are echovirus and coxsackievirus, but there are several others. Enteroviruses also cause polio and hand, foot and mouth disease (HFMD).
- Mild symptoms of enterovirus infection may include fever, runny nose, sneezing, cough, and body, and muscle aches.
- Children with asthma are particularly at risk for severe symptoms from enterovirus infection.
- There is no specific treatment for enterovirus infections.
- The most important thing you can do to stay healthy is to wash hands often with soap and water for 20 seconds.
What Parents Need to Know
Enteroviruses of various types cause about 10 to15 million infections each year in the US, usually in the late summer or early fall.
The vast majority of people infected with enteroviruses—over 90%—will either have no symptoms or have non-specific symptoms, such as sudden fever. A wide range of symptoms can be caused by enteroviruses but most often include fever, mild respiratory symptoms, flu-like illness with fever and muscle aches, fever with a rash and gastrointestinal symptoms.
The vast majority of children with enteroviruses, such as EV-D68, have mild symptoms and do not need any medical care beyond what is done for the common cold.
In many cases, enteroviruses don’t cause symptoms. If they do, the symptoms are often mild. Most symptoms usually go away in a few days and can include:
- Muscle aches
- Sore throat
- Runny nose
- Trouble breathing
- Nausea and vomiting
- Red sores in the mouth, and on the palms of the hands and soles of the feet (hand-foot-and-mouth disease)
- A red rash over large areas of the body
The symptoms of an enterovirus can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.
Children with a high fever and those with cold symptoms lasting longer than 7-10 days should talk with their pediatrician.
Those with difficulty breathing should seek emergency care.
Infants, children with asthma, and those with weak immune systems have a greater chance of breathing problems and complications; some requiring treatment in the intensive care unit. Pregnant women who get infected with an enterovirus shortly before delivery can pass the virus to their babies.
Information for parents of children with asthma:
This virus is particularly hard on children’s lungs. Therefore, it is especially important for parents of children previously diagnosed with asthma to:
- Help your child follow his or her asthma action plans.
- Communicate with your child’s pediatrician or subspecialist to plan in advance for times when symptoms may need urgent medical care.
- Take prescribed asthma medications as directed, especially long-term control medication(s).
- Keep the reliever (rescue) medication (inhaler or nebulizer) on hand.
- Get the seasonal influenza vaccine as soon as the vaccine is available because an influenza infection in the lungs can trigger asthma attacks and a worsening of asthma symptoms.
- Make sure the child’s caregiver and/or teacher is aware of his condition, and that they know how to avoid asthma triggers and what to do if the child experiences any symptoms related to asthma.
- Although no children should be exposed to secondhand smoke, it is especially important to prohibit smoking in homes and cars where children with asthma live.
Most illnesses caused by enteroviruses are mild but more severe diseases can sometimes develop in certain patients, including brain and heart conditions, pneumonia and hepatitis. Also, the viruses can spread to other organs such as the spleen, liver, bone marrow, skin, and heart.
Enteroviruses are usually diagnosed clinically by a doctor judging a patient’s symptoms to see if they have one of these viruses.
However, laboratory tests on some samples from patients can help to detect enteroviruses in more severe cases.
A healthcare provider will ask about your child’s symptoms and health history. The provider will do a physical exam. This may include an exam of the mouth, eyes, and skin. The healthcare provider will listen to your child’s chest as he or she breathes.
- Clinical evaluation
- Sometimes culture or reverse transcriptase-polymerase chain reaction (RT-PCR)
The diagnosis of enteroviral diseases is usually clinical.
Laboratory diagnosis is usually unnecessary but can often be made by
- Culturing the virus
- Detecting viral RNA using RT-PCR
- Less commonly, demonstrating seroconversion
In the case of severe symptoms, your child may need certain tests. These are done to see if your child has an enterovirus, or has a different kind of illness. The tests can look for problems in the heart, lungs, and brain. The tests may include:
- Virus culture. The healthcare provider takes a small sample of saliva, blood, urine, or stool. It is then tested for a virus.
- Polymerase chain reaction (PCR). The healthcare provider takes a small sample of blood, urine, or saliva. The sample is tested for a virus.
- Spinal fluid test. The healthcare provider takes a small sample of spinal fluid. This is done by putting a small needle into your child’s back. The fluid is tested for levels of certain chemicals and cells.
- Blood test. The healthcare provider takes blood from a vein. It is then tested for chemicals that may show the cause of your child’s illness, or show organ problems.
- X-rays. This test is done to look at the lungs and heart.
- Electrocardiogram (ECG). This test is done to look at the electrical activity of the heart.
- Echocardiogram. This test uses sound waves and a computer to look at the structure and movements of the heart.
Enteroviruses that cause aseptic meningitis can be detected in a sample from the throat, stool, blood, or cerebrospinal fluid with RT-PCR tests done on blood and cerebrospinal fluid. However, human parechoviruses are not identified by most standard enterovirus RT-PCR tests; specific parechovirus RT-PCR testing is required. Commercially available multiplex PCR panels for respiratory pathogens often cannot distinguish between rhinoviruses and enteroviruses.
Enteroviruses are the most prevalent viruses in the world. Anyone can develop symptomatic illness caused by enteroviruses, but children, particularly those younger than 10-years-old, are most likely to be infected. People most likely to develop a more severe disease are those with underlying health conditions, pregnant women, newborns or premature babies, and people who have cold stress or malnutrition.
Risk of enterovirus infections:
- Wash hands often with soap and water for 20 seconds, especially after changing diapers.
- Avoid touching, eyes, nose, and mouth with unwashed hands.
- Avoid kissing, hugging, and sharing cups or eating utensils with people who are sick.
- Disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.
- Stay home when feeling sick, and consult with your health care provider.
To protect against the flu virus, the American Academy of Pediatrics recommends all children ages six months and older get their flu vaccine at the earliest possible time.
How are enteroviruses spread?
Enteroviruses are spread by close contact with an infected person. You can also become infected by touching objects or surfaces that have the virus on them and then touching your mouth, nose, or eyes.
- Wash hands often with soap and water for 20 seconds.
- Avoid touching eyes, nose, and mouth with unwashed hands.
- Avoid close contact, such as kissing, hugging, and sharing cups or eating utensils, with people who are sick.
- Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands.
- Clean and disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.
- Stay home when you are sick and keep sick children out of school.
Most patients with enterovirus infection recover uneventfully. Treatment is usually supportive, aimed at relieving symptoms and making sure people keep hydrated. People with more serious infections will need more intensive support. Antibiotics are only given if a secondary bacterial infection is suspected alongside the enterovirus.
Treatment of the enteroviral disease is supportive. Patients with agammaglobulinemia are treated with IV immune globulins with variable success. The oral antiviral drug pleconaril, which has shown activity against a number of picornaviruses, is being investigated for the treatment of severe neonatal enteroviral disease.
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.
Antibiotics don’t work on viral illnesses like enterovirus. And no antiviral medicines are available to help cure an enterovirus infection. Instead, treatment is done to help your child feel better while his or her body fights the illness. This includes:
- Pain medicine. These include acetaminophen and ibuprofen. They are used to help ease pain and reduce fever. Don’t give aspirin to your child if he or she has a fever.
- Oral pain reliever (anesthetic). This is a gel used to help ease the pain of sores in the mouth.
- Bed rest. This helps your child’s body fight the illness.
- Change in diet. If your child has painful mouth sores, give only bland, soft foods. Don’t give your child salty or crunchy foods.
In severe cases, treatment may include:
- Opioid medicines for severe pain
- Medicine for heart problems
- IV (intravenous) fluids for dehydration
- Medicine called immunoglobulin given through an IV
- Antiviral medicine
Symptoms such as muscle aches, fever, and sore throat usually go away in a few days. The red sores are known as hand-foot-and-mouth disease usually go away in 7 to 10 days.
Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all medicines.
Rarely, hemorrhagic conjunctivitis occurs in epidemics in the US. Importation of the virus from Africa, Asia, Mexico, and the Caribbean may make outbreaks more common.
The eyelids rapidly swell. Hemorrhagic conjunctivitis, unlike uncomplicated conjunctivitis, often leads to subconjunctival hemorrhages or keratitis, causing pain, tearing, and photophobia. Systemic illness is uncommon. However, when hemorrhagic conjunctivitis is due to enterovirus 70, transient lumbosacral radiculomyelopathy or poliomyelitis-like illness (with paralysis) can occur but is rare. Recovery is usually complete within 1 to 2 weeks of onset.
Coxsackievirus A24 also causes hemorrhagic conjunctivitis, but subconjunctival hemorrhage is less frequent, and neurologic complications have not been described. Most patients recover in 1 to 2 weeks.
Cardiac infection may occur at any age, but most patients are 20 to 39 years old. Patients may present with chest pain, arrhythmias, heart failure, or sudden death. Recovery is usually complete, but some patients develop dilated cardiomyopathy. Diagnosis of myopericarditis may require reverse transcriptase (RT)–PCR of myocardial tissue.
Myocarditis neonatorum (cardiac infection at birth) is caused by group B coxsackieviruses, some echoviruses, and human parechoviruses. It causes fever and heart failure and has a high mortality rate.
Usually, several days after birth, the neonate suddenly develops a syndrome resembling sepsis with fever, lethargy, disseminated intravascular coagulation, bleeding, and multiple organ (including heart) failure. The central nervous system, hepatic, myocardial, pancreatic, or adrenal lesions may occur simultaneously.
Recovery may occur within a few weeks, but death may result from circulatory collapse or, if the liver is involved, liver failure.
Certain coxsackieviruses, echoviruses, and human parechoviruses may cause rashes, often during epidemics. Rashes are usually nonpruritic, do not desquamate, and occur on the face, neck, chest, and extremities. They are sometimes maculopapular or morbilliform but occasionally hemorrhagic, petechial, or vesicular. Fever is common. Aseptic meningitis may develop simultaneously.
These infections may result from enteroviruses. Symptoms include fever, coryza, pharyngitis, and, in some infants and children, vomiting and diarrhea. Bronchitis and interstitial pneumonia occasionally occur in adults and children.