Enterovirus

An enterovirus is a common type of virus. A virus is a microscopic organism that can spread from person to person and cause illness. Enteroviruses are highly contagious (easily spread to others).

Your body’s immune system is a complex network of white blood cells, organs, and tissues that helps fight off infections and diseases. The immune system can prevent enterovirus infection in many cases. But sometimes, the virus breaks through the defenses of the immune system and reaches the bloodstream, which can result in illness.

Infants, children, and teens are most susceptible to enterovirus infections. Because most adults have been exposed to enteroviruses before in their lives, they’ve built up an immunity (resistance) to the virus. This lowers their risk of getting sick. Immunity is achieved when the immune system produces enough antibodies to prevent the illness caused by exposure to that virus. (Antibodies are proteins created by the body in response to a certain virus.)

Enterovirus infections in the U.S. most often occur in the summer and fall. Common symptoms of enterovirus infection include sore throat, cough, fever, headache, rash, and mouth sores. Symptoms may be worse in people who have compromised immune systems. A person’s immune system may be weakened as a result of taking certain types of medications (such as immunosuppressants) or having certain medical conditions (such as HIV, cancer, or alcohol use disorder).

Enterovirus treatment focuses on relieving symptoms while the immune system works to eliminate the virus. Most people with enterovirus infections make full recoveries.

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There are more than 100 different strains (types) of enteroviruses. Most of these can be categorized as non-polio enteroviruses and polioviruses.

Non-polio enteroviruses

Non-polio enteroviruses make up the majority of enteroviruses. They usually cause mild symptoms, if any at all. These viruses include coxsackieviruses, echoviruses, and

rhinoviruses.

Various strains of non-polio enteroviruses circulate among people each year. Outbreaks of certain enteroviruses can also occur periodically within different communities.

Some of the most well-known strains of non-polio enteroviruses include:

• Enterovirus D68 (EV-D68): Enterovirus D68 tends to cause respiratory illness that resembles the common cold, though children with asthma have an increased risk of more severe symptoms. Rarely, EV-D68 causes a serious neurological condition called acute flaccid myelitis, or AFM (more on this below).
• Enterovirus A71 (EV-A71): Enterovirus A71 usually causes mild cases of hand, foot, and mouth disease (HFMD), which commonly affects babies and young children (more below). Rarely, AFM can occur as a result of enterovirus A71 infection.
• Coxsackievirus A16 (CV-A16): Coxsackievirus A16 is generally the most common cause of hand, foot, and mouth disease in the U.S.
• Coxsackievirus A6 (CV-A6): Coxsackievirus A6 may cause more severe cases of hand, foot, and mouth disease, including disease in adults.

Polioviruses

Polioviruses cause polio (poliomyelitis), a potentially severe illness without a cure. Severe cases of polio can lead to trouble breathing, paralysis (difficulty moving or inability to move certain parts of the body), and even death. Polio is now largely eliminated in the U.S. thanks to the introduction of the polio vaccine in 1955. But cases emerge occasionally in the U.S. and outbreaks occur periodically in other parts of the world.

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Signs and symptoms of enterovirus can vary depending on the strain of virus and other factors, such as the health of the affected person. (Someone with an underlying condition like asthma or a weakened immune system may experience more severe symptoms.) In many cases, enteroviruses don’t cause any symptoms.

When enterovirus symptoms are present, they may include one or more of the following: 

• Fever
• Sore throat
• Cough
• Muscle aches
• Runny nose
• Headache
• Sneezing
• Mouth sores  
• Sores on the hands or feet
• Skin rash, which may be red or discolored and cover a large area of the body
• Nausea and vomiting
• Diarrhea

An enterovirus infection that causes fever, sore throat, and headache is sometimes called a “summer flu,” though the actual flu (influenza) is caused by an influenza virus, not an enterovirus.  

Enterovirus infection shares several symptoms with other common conditions, such as strep throat, allergies, influenza, pertussis (whooping cough), and bronchitis. Only an HCP can detemine if enterovirus is the cause of your or your child’s symptoms.

Symptoms of enterovirus are usually mild and pass in a few days or weeks. Less commonly, more serious symptoms like trouble breathing and enterovirus-related diseases can occur.

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Enterovirus can be found in an infected person’s saliva, mucus, and stool (poop). The virus can also live in the fluid inside blisters that form on the skin or inside of the mouth.

Enteroviruses are highly contagious. Like many other viruses, enteroviruses can be spread through:

• Inhaling airborne droplets from an infected person’s cough or sneeze
• Direct contact (such as a hug or handshake) with an infected person
• Drinking beverages or eating foods contaminated with an infected person’s saliva, mucus, or stool
• Touching contaminated surfaces or objects (such as a dirty diaper or baby wipe) then touching your mouth, nose, or eyes. (Enteroviruses can survive on surfaces for several days.)

You can transmit an enterovirus to other people for several weeks after you become infected, even if you’re not experiencing symptoms.

Pregnancy and enterovirus transmission

A pregnant person can also spread an enterovirus to their baby if they become infected shortly before giving birth. While most pregnant adults have previously been exposed to enteroviruses and are immune to the illnesses they cause, a baby is more likely to become sick.

Enterovirus infections in newborns are usually mild and resolve in a few weeks, but severe illness is possible. Enterovirus may lead to meningitis, myocarditis, or a serious infection called sepsis that can cause organ failure or death. (Read more on these complications below.) 

Contact your HCP right away if your newborn has a fever or is unusually sleepy or unresponsive. You should also speak with your HCP before breastfeeding if you’re feeling ill or suspect you may have an infection. 

There’s currently no conclusive evidence that an enterovirus infection in a pregnant person increases the risk of miscarriage, stillbirth, or congenital differences in a fetus.

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Enteroviruses are very common and affect just about everyone at some point. Babies, children and teens are more likely to get enterovirus infections and become sick than adults, since they haven’t yet built up immunity to the virus.

Enterovirus infections are usually mild, but infants and people with weakened immune systems have a higher risk of experiencing severe symptoms and complications than others.

There are several factors that can weaken a person’s immune system and lower their defenses against infections like enterovirus, including:

• Having certain medical conditions: These include but are not limited to HIV/AIDS, kidney disease, cancers such as leukemia and multiple myeloma, mononucleosis, diabetes, and autoimmune diseases like rheumatoid arthritis and lupus
• Being pregnant
• Receiving a tissue or organ transplant
• Receiving chemotherapy and other treatments for cancer
• Taking certain drugs: These include immunosuppressants for certain cancers and autoimmune diseases, tumor necrosis factor (TNF) inhibitors for autoimmune diseases, and corticosteroids for conditions such as inflammatory bowel disease and arthritis.
• Certain lifestyle and health factors: These include experiencing frequent stress, smoking, consuming heavy amounts of alcohol, regularly getting poor sleep, and having obesity.

Having certain respiratory conditions, such as asthma or chronic obstructive pulmonary disorder (COPD), also increases your risk of experiencing severe enterovirus symptoms.

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In addition to causing mild illnesses with cold or flu-like symptoms, enteroviruses can infect organs and result in other conditions. These include, but aren’t limited to:

Conjunctivitis

Also called pink eye, conjunctivitis is a common condition characterized by inflammation (swelling and irritation) of the conjunctiva. This is the thin membrane that covers the front of the eye and the inside of the eyelid.

Symptoms of conjunctivitis include eye redness (or “pinkness”) and itchiness. The affected eye or eyes may also appear puffy and produce fluid discharge, which can form a crust overnight.

Treatment for conjunctivitis involves using artificial tears and cold compresses to relieve symptoms as the body works to clear the infection. Most cases of viral conjunctivitis resolve within a few weeks.

Acute flaccid myelitis

Some enterovirus A71 and enterovirus D68 infections can progress to damage the spinal cord and cause weakness and paralysis in the arms and legs. This is known as acute flaccid myelitis (AFM). With fewer than 700 reported cases in the U.S. since 2014, AFM is a rare disease that isn’t well understood. 

In addition to weakness in or trouble moving the arms or legs, possible symptoms of AFM include:

• Slurred speech
• Trouble swallowing
• Droopy face or eyelids
• Difficulty moving the eyes
• Labored breathing

AFM treatment may include medications and therapies to relieve symptoms and restore movement to the arms and legs. Many children with AFM attend physical and occupational therapy programs for weeks or months. Nerve transfer surgery to help restore nerves and

improve mobility may sometimes be recommended.

Hand, foot, and mouth disease

Several types of enteroviruses can cause hand, foot, and mouth disease (HFMD). Common in young children, HFMD results in symptoms like painful mouth sores, fever, and an itchy rash on the hands and feet. Rashes may also appear on other areas of the body, such as the arms, genitals, and buttocks.  

Treatment for HFMD focuses on relieving symptoms. Acetaminophen and ibuprofen may be used to help lower fever. (Keep in mind that aspirin should not be given to children and teenagers, as it increases the risk of a serious condition called Reye’s syndrome that causes swelling in the brain and liver.)

To help heal mouth sores, rinse mouth out with salt water, stay hydrated by drinking enough water, and eat only soft foods that aren’t salty or acidic.

HFMD usually causes mild symptoms and resolves quickly. Rarely, meningitis and encephalitis may occur.  

Meningitis

Inflammation of the tissues that cover the brain and spinal cord is called meningitis. Most cases of meningitis are caused by bacteria. When meningitis results from something other than bacteria, such as an enterovirus, it’s known as aseptic meningitis. Symptoms of aseptic meningitis include an intense headache, fever, a stiff neck, sensitivity to light, and vomiting.  

Most people with enterovirus-related meningitis recover on their own in a few weeks. Taking acetaminophen can help relieve headaches and lower fever as the immune system works to clear the infection.

Encephalitis

Inflammation of the brain itself is called encephalitis. It may occur alongside meningitis, which affects the tissues that surround the brain and spinal cord. Symptoms of encephalitis include headache, fever, vomiting, weakness, confusion, seizures, and coma (a prolonged period of unconsciousness).  

Treatment for enterovirus-related encephalitis involves reducing symptoms with medication. Most cases of encephalitis subside in a few weeks. An HCP may use life-supporting measures, such as inserting a breathing tube, in more severe cases. 

Pericarditis

Pericarditis is a condition in which the pericardium (the protective sac that surrounds the heart) becomes inflamed. Pericarditis caused by an enterovirus or another virus is called viral pericarditis.

Symptoms of pericarditis often resemble those of a heart attack. They may include stabbing or sharp chest pain, pain that radiates to the left arm or shoulder, and shortness of breath. Fever, chills, dizziness, and pain that worsens when breathing deeply may also occur.

Treatment for viral pericarditis usually involves taking medications to relieve pain and inflammation as the immune system works to clear the infection.

Myocarditis

Myocarditis refers to infection of the heart muscle. When this infection spreads to the pericardium, it’s known as myopericarditis. Symptoms of myocarditis include chest pain, fatigue, difficulty breathing, and heart palpitations (an unusually fast, slow, or fluttering heartbeat). Although rare, heart failure, dilated cardiomyopathy (an enlarged heart), and death may occur.

Treatment for enterovirus-related myocarditis involves medications and therapies to support heart health and prevent complications. Most people with myocarditis make full recoveries.

Epidemic pleurodynia

Also known as Bornholm disease, epidemic pleurodynia affects chest muscles and causes symptoms like intense chest or upper abdominal pain on one side of the body. This pain typically comes in waves that may last a few minutes or a few hours. Painful breathing, fever, sore throat, and headache may also occur.  

Epidemic pleurodynia usually goes away on its own in a few days. Taking an over-the-counter pain reliever can help ease muscle pain and other symptoms as the immune system works to resolve the infection.

Herpangina  

Herpangina is a common childhood illness that causes sudden sore throat, fever, loss of appetite, and sometimes neck pain. Gray-colored sores appear in the mouth and throat a few days after symptoms begin. Due to the presence of mouth sores, herpangina is often mistaken for hand, foot, and mouth disease.

Herpangina usually resolves on its own in a week or so. Topical analgesics (pain-reliving medicines applied directly to the skin or affected tissue) can be used to help soothe mouth sores. Taking pain relievers such as acetaminophen or ibuprofen can lower fever and ease pain.  

Pneumonia  

Pneumonia is an infection of the lungs. When pneumonia is caused by an enterovirus or another virus, it’s known as viral pneumonia. Symptoms of viral pneumonia may include fever, fatigue, headache, a cough that produces mucus, and shortness of breath that comes with physical activity.

Many people with mild viral pneumonia can improve their symptoms by getting plenty of rest and fluids. Acetaminophen or ibuprofen may be used to help lower fever and relieve headaches. Some people may need to receive supplemental oxygen in a hospital setting if their oxygen levels are low.

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Promptly contact an HCP if your child is ill and:

• Is younger than 3 months old
• Has labored or difficult breathing 
• Is showing signs of dehydration, including sunken eyes, unusual fatigue, dry diapers, dry mouth, or a lack of tears when crying
• Has changes in vision, eye pain, or eye redness
• Has a weakened immune system
• Has a high fever or a mild fever that lasts for two days (in children younger than 2 years old) or three days (in children 2 years or older)   
• Has severe diarrhea (watery bowel movements every one to two hours or more frequently)

Children between the ages of 3 and 36 months should be evaluated by an HCP if their armpit temperature is 101 degrees Fahrenheit or higher, or if their forehead, ear, or rectal temperature is greater than 102 degrees. (Avoid using an oral thermometer in children younger than 4 years.) Children of any age should receive medical care if they have a fever of 104 degrees or higher.

It’s also important to speak with an HCP if you’re an adult with possible symptoms of an enterovirus infection, especially if you have a weakened immune system or an underlying respiratory condition such as COPD or asthma.

In general, it’s a good idea for an adult to visit an HCP if symptoms:

• Worsen or fail to improve after a few days
• Include wheezing, shortness of breath, or intense sinus pain or headache
• Include a fever that goes away but then returns
• Include a fever that stays higher than 101.3 degrees Fahrenheit for three or more days

When to call 911

Though uncommon, it’s possible for enterovirus infections to cause life-threatening health concerns. Call 911 or visit your nearest hospital emergency department if you or someone around you experiences any of the following:

• Chest pain that lasts for more than two minutes
• Trouble breathing
• Vomiting or coughing up blood
• Vomiting that is severe or persistent
• Loss of consciousness
• Sudden dizziness, confusion, weakness, or changes in vision
• Intense abdominal pain or pressure
• Skin that appears bluish
• A severe or unusual headache 
• Difficulty speaking or understanding others

In young children, the following signs and symptoms could also indicate a medical emergency: 

• Increased sleepiness, listlessness, or irritability
• Reduced alertness
• Labored or unusual breathing
• Fever followed by neck or back stiffness
• Unusual difficulty standing and walking
• Seizures
• Trouble feeding or eating

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Diagnosing an enterovirus infection starts with a review of a person’s symptoms and medical history. An HCP will likely perform a physical exam to evaluate heartbeat and check for signs of infection, such as eye irritation and mouth or skin sores.

Your HCP may not run any diagnostic tests if you or your child are only experiencing mild symptoms. If symptoms are severe or indicate a more serious condition, your HCP may use one or more tests to determine what’s causing the illness and suggest appropriate treatment. 

These tests may include:

• A saliva, urine, or stool test to screen for viruses or bacteria
• A blood test to screen for viruses, bacteria, or chemical imbalances that could indicate organ damage  
• X-ray imaging to view images of the heart and lungs and check for signs of disease
• A spinal fluid test to measure levels of certain cells and chemicals in a small sample of spinal fluid, which is drawn out of the spine using a needle
• An echocardiogram to examine the structure and function of the heart by viewing moving images produced by soundwaves
• An electrocardiogram (ECG or EKG), which uses patches placed on the chest to record the heart’s electrical signals

What questions should you ask your healthcare provider?

Whether you or your child has an enterovirus infection, asking your HCP questions about the virus can allow you to make informed treatment decisions and help prevent future infections.

Some questions you might ask include:

• What enteroviruses are most common in my area? 
• How long are enteroviruses contagious?
• How can I protect myself or my child from enteroviruses?
• When should I worry about enterovirus symptoms?
• What self-care measures can help treat an enterovirus infection? 
• What activities should I avoid while I’m sick? Should I change my diet?
• How can I lower the risk of enterovirus complications?
• How long does an enterovirus stay in a person’s body?

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Treatment for enterovirus infections focuses on relieving symptoms. HCPs such as primary care providers and pediatricians (medical doctors who specialize in children’s health) can provide enterovirus treatment.

Antibiotics, which are used to treat bacterial infections, aren’t effective against enterovirus infections. Neither are currently available antiviral medications, which can help shorten the duration and severity of other viral infections. Most enteroviruses are resolved by the body’s immune system in a few days or weeks.

Your or your child’s HCP may recommend the following to help ease symptoms and promote a healthy immune response as the virus runs its course:

Medication

Oral medications such as ibuprofen or acetaminophen can lower fever and reduce pain. (Remember, children and teens should not take aspirin.) An oral anesthetic gel may be used to soothe painful mouth sores. Taking cough syrup or a nasal decongestant can also ease a nagging cough or stuffy nose, respectively. Talk to your HCP about using cold medicines in children, as they should not be used in kids younger than 2 years of age.

Be sure to take all medications according to package directions or your HCP’s guidance. Promptly report any unexpected symptoms to your HCP.  

Rarely, medications to address severe pain or heart issues may be prescribed if complications occur.

A nourishing diet

A healthy diet that includes plenty of vegetables, fruits, lean proteins, and whole grains can equip your body with the nutrients it needs to fight off an infection. Stay away from sweets and fried and fatty foods, which can make an upset stomach worse. Avoid crunchy or salty foods if mouth sores are present. If you or your child are unable to eat without vomiting, wait until symptoms resolve to start snacking.

Many people who are experiencing nausea, vomiting, or diarrhea find it helpful to follow the “BRAT” diet, which stands for:

• Bananas
• Rice
• Applesauce
• Toast

Sticking to these simple, bland foods for one to two days can help ease digestive symptoms of an enterovirus infection as well as other illnesses, such as the flu and gastroenteritis (“stomach flu”).

Rest and fluids

Prioritizing rest and getting enough fluids is important during sickness. If your child is sick, keep them home from daycare, school, or sports. Ample rest is equally important for adults who are fighting infections.

Water is the best fluid to drink when sick. Consuming beverages that contain electrolytes (minerals including magnesium, sodium, and potassium) can help replenish lost fluids and nutrients and prevent dehydration. They may be particularly useful after vomiting, moderate or severe diarrhea, or running a fever. But be sure to avoid boiled milk, sugary juices, sodas, and sugar-loaded electrolyte drinks, as these can make dehydration worse.

Eating foods that are high in water content can also help keep you or your child hydrated when sick. For example, sip soup, enjoy a fruit smoothie, or snack on water-rich foods like:

• Strawberries
• Watermelon
• Cucumbers
• Oranges
• Apples
• Tomatoes
• Celery
• Grapes
• Cantaloupe

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Enteroviruses are common and easily spread, so they’re difficult to avoid entirely. But there are steps you can take to help lower the risk of enterovirus infections. For example:

• Avoid contact with sick people. Don’t shake hands or hug someone who is sick. If you or your child are sick, stay home until symptoms resolve or your HCP gives you the green light to go back to work or school.
• Regularly clean and disinfect frequently used surfaces. These include things like doorknobs, handrails, keyboards, favorite toys, and countertops.
• Wash your hands thoroughly and often. People of all ages should wash their hands for at least 20 seconds with soap and water.

Parents, caregivers, and guardians should teach their children the importance of proper hand washing. It’s especially important to wash hands:

• After sneezing or coughing
• Before touching your face
• Before eating
• After using the bathroom
• After changing diapers

Carry hand sanitizer for you and your child to use when you don’t have access to a sink and soap.

Poliovirus vaccination

Infection with poliovirus—the strain of enterovirus that causes polio—is preventable with vaccination. The polio vaccine is currently the only vaccine that protects against an enterovirus. It involves a series of four vaccinations that begins at 2 months old and ends between the ages of 4 and 6 years. The Centers for Disease Control and Prevention (CDC) also advises adults who have never been vaccinated against polio to receive a series of three vaccinations over the course of 7 to 14 months.

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Most enterovirus infections are mild and cause cold- or flu-like symptoms that resolve on their own in one to two weeks. Some infections don’t cause any symptoms. The vast majority of people with enterovirus infections make full recoveries.

Less commonly, enterovirus infections can worsen asthma and COPD symptoms. Complications such as encephalitis, meningitis, irreversible paralysis, and respiratory failure are rare but possible. Promptly treating symptoms and reporting any changes in health to your HCP can help prevent serious illness and complications.

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Contact your HCP to learn more about enteroviruses and how you can help prevent infections in you or your child. The CDC offers helpful advice for people who would like to learn more about non-polio enteroviruses and polio vaccination.

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• Enterovirus D68: What Parents Need to Know   
• 9 Ways to Avoid Germs Throughout Your Day
• 6 Ways to Protect Kids With Asthma from EV-68