Updated August 24, 2015.

Enterovirus is a common virus that includes many different disease strains, including polio. One strain, Enterovirus-D68 or EV-D68, spread respiratory disease in the fall of 2014 from Missouri to throughout the Midwest then into the South and Northeast and the rest of the country. It mostly affected children, particularly those with asthma.

Key facts about Enterovirus D-68:

• Most affected are children

• Children with asthma at most risk
• Wash hands with soap and water (not hand sanitizers)
• The virus can linger on counter tops, doorknobs, toys if touched
• Most children who are sick do not have a fever
• Some children have difficulty breathing and need to go to the hospital
• There is no vaccine or specific treatment. Most get better quickly
• Enteroviruses are common illnesses. D-68 is just a rare strain.

Basics

Enteroviruses can cause sudden outbreaks of disease. 10-15 million are infected by different strains annually in the US. There is no specific treatment. There is no vaccine in the US for enteroviruses, except for polio, which does not work on EV-D68. Abroad there are only vaccines for a different strain.

Most enterovirus infections cause no symptoms - or at most only a fever or a cold - and are never identified.

There are severe syndromes associated with particular subtypes, like EV-D68. 

Respiratory: Enterovirus D68 EV-D68

Symptoms can be like a common cold. EV-D68 may, however, develop into a severe infection requiring hospitalization.

Symptoms usually include difficulty breathing and wheezing. Most do not have a fever. Fewer than 1 in 4 had a fever.

Asthmatic children are at higher risk. Those initially hospitalized have been young (6 weeks to 16 years) and asthmatic (68%). 

Anyone with difficulty breathing should immediately seek medical attention. There is no specific treatment, but oxygen and hospital care may be needed.

In August 2014, an Enterovirus-D68 identified in children in Kansas City, Missouri. By October it had reached 45 states. Well over 1000 children were reported ill; 15% of those hospitalized needed intensive care. 

The disease has been rare around the world, but there have been limited, but severe disease has been noted. There have been reports of paralysis. There were few deaths; only 2 conclusively linked as of October 12, 2014.

Other strains:

There are different enterovirus types, with different strains varying around the world. Polioviruses are enteroviruses. The remaining Non-Polio Enteroviruses are divided into 4 categories: Coxsackievirus A, Coxsackievirus B, Echovirus, and numbered Enteroviruses. There are 62 non-polio enteroviruses are known to cause disease.

Encephalitis

Encephalitis is inflammation of the brain, causing tiredness, comas, seizures, loss of movement or coordination.

EV71 is a serious infection in Asia, causing large outbreaks there, but not in the US. In can rarely cause neurologic effects, such as brain-stem encephalitis that delay neurodevelopment. 

Two vaccines have been developed for this strain and appear promising - but only for EV71.

Hand Foot and Mouth Disease  (HFMD)

Blisters develop on the hands, sometimes feet, and mouth that are clear or gray and surrounded by red rings. These hurt and last about 1 week.

Coxsackievirus A16 is the most common HFMD strain in the US, except Coxsackievirus A6  predominated in 2011-12.  Coxsackievirus A6 causes more severe illnesses, sometimes needing hospitalization.

Herpangina

A few small "Mouth blisters" develop in the back of the mouth, near the tonsils, with a sore throat and fever. They may ulcerate. Blisters heal in 7-10 days. 

Coxsackie A4, 10, 5, 6, 2 and 3 are associated.

Myopericarditis

Myopericarditis is the inflammation of pericardium (sac surrounding the heart) and heart muscle - causing shortness of breath, fatigue, chest pain - often worse lying down. Patients can develop heart failure, with excess fluid in feet and lungs. In rare cases, heart damage may be life-threatening.

It can be caused by coxsackieviruses A4, B3, B2.

Acute Hemorrhagic Conjunctivitis (AHC)

Eyes appear bloodshot for 5-7-days, before resolving, usually without eye problems.

Coxsackievirus A24 and enterovirus 70 are associated with conjunctivitis and AHC.

Viral (asceptic) Meningitis

Meningitis is the inflammation of the meninges (membrane surrounding brain and spinal cord). Patients have fever, headache and sometimes confusion, loss of consciousness, impaired function. 

Echoviruses 13, 18, and 30 are associated.

Paralysis

Enterovirus 70 rarely causes a polio-like paralysis.

Neonatal Sepsis

Severe neonatal sepsis occurs with coxsackievirus B1

Pleurodynia

Fever with sudden chest pain in lower ribs from muscle damage

It is rare and associated with Echovirus 1.

Longterm Consequences

Enteroviruses are associated with Autoimmune Disorders. Some hypothesize Type 1 Diabetes and other disorders may develop after enterovirus infections.

Transmission:

Non-polio enteroviruses can be found in stool, eye, nose, or mouth secretions. The disease can spread by contact (handshakes), touching objects touched by others ("fomites"), changing diapers, drinking contaminated water. Patients can spread some strains through stool or respiratory secretions weeks after symptoms pass. Labor or breastfeeding can transmit infection. Symptoms usually develop 3-6 days after exposure.

Children lack of prior exposure and immunity. There is only some cross-immunity between different enteroviruses; adults usually have had multiple strains.

Infections:

Because infections may cause no symptoms, wash your hands - especially before eating, when using bathrooms, changing diapers, visiting anyone ill.

Wash your hands with soap and water. Enteroviruses are poorly disinfected by alcohol-based hand sanitizers. Avoid shaking hands. Cover sneezes with a tissue or upper sleeve. Clean surfaces. Avoid touching your face.

There is no vaccine in the US. Diagnosis is made by PCR. There is no specific treatment.