An enterovirus is a type of small, hardy virus that primarily infects through the gut and respiratory tract. More than 110 types have been identified, and they cause a remarkably wide range of illnesses, from the common cold and hand, foot, and mouth disease to rare but serious conditions like meningitis and paralysis. Most enterovirus infections are mild or cause no symptoms at all, but certain strains can be dangerous, particularly for infants and young children.
The Enterovirus Family
Enteroviruses belong to the Picornaviridae family, a large group of viruses that infect vertebrates. The enterovirus genus itself contains 15 species, including three species of rhinoviruses (the main cause of the common cold) and enterovirus species A through L. The ones that matter most for human health fall into four groups: Enterovirus A, B, C, and D.
Within those groups sit many familiar names. Poliovirus is an enterovirus. So are coxsackieviruses A and B, echoviruses, enterovirus D68, and enterovirus A71. Each of these has different tendencies in the body, which is why enteroviruses as a whole can cause such a diverse set of illnesses.
One important physical trait: enteroviruses lack a fatty outer envelope. This makes them tougher to kill on surfaces. Standard alcohol-based hand sanitizers have limited effectiveness against some strains, and common hospital-grade quaternary ammonium disinfectants generally don’t inactivate them. Bleach solutions (chlorine-based cleaners) are more reliable.
How Enteroviruses Spread
The classic route is fecal-oral. The virus replicates in the gut, sheds in stool, and spreads when someone touches a contaminated surface, food, or water and then touches their mouth. This is why outbreaks often hit daycare centers, where diaper changes and shared toys create ideal conditions.
Some enteroviruses also spread through respiratory droplets, and a few prefer that route almost exclusively. Enterovirus D68, for instance, spreads primarily through coughs and sneezes rather than through stool. Close household contact is a significant transmission risk. In a study of EV-D68 among household contacts in Colorado, all infected participants were still shedding detectable virus from their upper respiratory tract at five days after symptoms began, with a median shedding duration of 12 days. Other enteroviruses that spread through the gut can shed in stool for weeks.
Symptoms of Mild Infections
The majority of enterovirus infections either cause no symptoms or produce a generic illness that looks like many other viral infections: fever, runny nose, cough, body aches, and sometimes a skin rash or mouth blisters. This is why most people who’ve had an enterovirus infection never knew it by name.
Hand, foot, and mouth disease is the most recognizable mild enterovirus illness. It mainly affects children under five and causes fever along with small blisters on the hands, feet, buttocks, and inside the mouth. The usual culprits are enterovirus A71 and coxsackievirus A16. It’s typically self-limiting, resolving on its own within a week or so.
Herpangina, another common childhood illness, produces painful sores at the back of the throat and is caused by several coxsackievirus and echovirus types. Acute hemorrhagic conjunctivitis, a highly contagious eye infection, is linked to enterovirus D70 and a variant of coxsackievirus A24, and has caused explosive outbreaks in tropical regions.
Serious and Rare Complications
While uncommon, enteroviruses can cause severe disease. The range includes:
- Viral meningitis: inflammation of the membranes surrounding the brain and spinal cord. Multiple enterovirus types can cause this, including several coxsackieviruses and echoviruses. Most cases resolve without lasting damage, but they require medical evaluation.
- Encephalitis: infection of the brain itself, which is rarer and more dangerous than meningitis.
- Myocarditis: inflammation of the heart muscle, most often linked to coxsackievirus B strains. This can progress to dilated cardiomyopathy in some cases.
- Acute flaccid myelitis (AFM): sudden weakness or paralysis in one or more limbs, caused by damage to motor neurons in the spinal cord. This is the complication that drew national attention during outbreaks in 2014, 2016, and 2018.
Newborns are especially vulnerable. Infants infected with certain enteroviruses, particularly coxsackievirus B types and echoviruses, can develop sepsis, a potentially fatal whole-body response to infection.
Enterovirus D68 and Paralysis
Enterovirus D68 deserves special mention because of its link to AFM and because it behaves differently from most enteroviruses. It spreads through the respiratory tract rather than the gut and tends to cause respiratory illness that can range from mild cold symptoms to severe breathing difficulty, particularly in children with asthma.
In a small percentage of cases, EV-D68 infection progresses to AFM. The typical pattern is a respiratory illness with fever, followed roughly five days later by sudden limb weakness. Research has shown that EV-D68 can enter neurons, replicate inside them, and cause direct damage. Because the virus infects the respiratory tract, it may be more likely to affect the cervical spinal cord, which is why upper extremity weakness is common in AFM cases. The extent to which the damage comes from direct viral invasion versus the body’s own immune response remains an open question.
CDC surveillance data from 2025 shows EV-D68 accounting for nearly 57% of all typed enterovirus specimens reported, making it the most commonly detected strain in recent U.S. surveillance.
How Enteroviruses Are Diagnosed
Diagnosis relies on PCR testing, which detects the virus’s genetic material, or on growing the virus in cell culture followed by PCR identification. Preferred specimens are nasopharyngeal and throat swabs, though stool, cerebrospinal fluid, blister fluid, and blood can also be tested depending on symptoms.
Most people with mild enterovirus illness are never tested. Diagnostic testing typically happens when someone presents with a more serious condition like meningitis, AFM, or myocarditis, and doctors need to identify the cause. Non-polio enterovirus infections are not required to be reported to public health authorities in the United States, which means the true number of infections each year is far higher than surveillance numbers suggest.
Treatment Options
There is no FDA-approved antiviral drug for any enterovirus. Treatment for mild infections is supportive: rest, fluids, and fever management. For severe cases like meningitis or myocarditis, treatment focuses on managing symptoms and complications in a hospital setting.
Several antiviral candidates have been tested over the years, but none has reached the market. One drug targeting a key viral protein showed promise in the lab but had poor absorption in the body and was dropped from trials. Another candidate, CUR-N399, has completed early-stage trials. Even fluoxetine, which showed antiviral activity against EV-D68 in lab studies, failed to help patients with AFM in clinical testing.
The one major success story in enterovirus prevention is the poliovirus vaccine, which has nearly eradicated polio worldwide. No vaccine exists for the other 100-plus enterovirus types, though vaccines targeting EV-A71 have been developed and are used in some Asian countries where hand, foot, and mouth disease outbreaks are particularly severe.
Reducing Your Risk
Because enteroviruses lack the fatty envelope that makes many viruses easy to kill, standard precautions matter more than surface disinfection alone. Thorough handwashing with soap and water is the single most effective measure, especially after using the bathroom, changing diapers, and before eating. Soap and mechanical scrubbing physically remove the virus in ways that alcohol-based sanitizers may not fully accomplish for non-enveloped viruses.
For surface cleaning, bleach-based products are the most reliable option. Quaternary ammonium compounds, the active ingredient in many household disinfecting wipes and sprays, are generally not effective against non-enveloped viruses like enteroviruses. Avoiding close contact with sick individuals and not sharing cups or utensils during outbreaks also helps, particularly for respiratory-spread strains like EV-D68.