Overview of Coxsackievirus Infections

Next to norovirus, the coxsackievirus is probably one of the most common viruses that you have never heard of. First discovered in the 1940s, it is a type of non-polio enterovirus. This group of viruses also includes echoviruses and other enteroviruses (one of which, enterovirus D68, caused a nationwide outbreak of respiratory infections in the United States that was associated with acute flaccid paralysis).

While you might not be familiar with coxsackievirus, though, if you have a child there is a good chance that you do know about the infection and how one of its strains causes hand, foot, and mouth disease (HFMD). It's a common viral infection of early childhood, caused by coxsackievirus A16.

Altogether, there are 29 serotypes of coxsackievirus that can cause infections in people, including:

• Coxsackievirus A2-8, A10, A12, A14, A16 (a type of Human enterovirus A)
• Coxsackievirus A9 (a type of Human enterovirus B)
• Coxsackievirus B1-6 (a type of Human enterovirus B)
• Coxsackievirus A1, A11, A13, A17, A19-22, A24 (a type of Human enterovirus C)

Since it was first identified in 2008, coxsackievirus A6 has been causing more severe and atypical cases of HFMD in the United States and worldwide, including in adults.

Different Coxsackievirus Infections

Again, HFMD, with ulcers in a child's mouth and blisters on their hands and feet, is typically the most well-known infection caused by the coxsackievirus, but coxsackievirus is also associated with:

• Congenital Infections: infections in pregnancy that spread to the fetus
• Neonatal Infections: rare, but can cause bleeding problems, hepatitis, meningitis, meningoencephalitis, myocarditis, and sepsis, etc., and is highlighted by a nationwide outbreak of coxsackievirus B1 infections in 2007
• Acute Hemorrhagic Conjunctivitis: Coxsackievirus A24 can cause outbreaks of a pink eye with subconjunctival hemorrhages
• Gastrointestinal Disease: Coxsackievirus can cause hepatitis, nonbacterial diarrhea, or gastroenteritis, and HUS.
• Herpangina: similar to HFMD, with oral ulcers, but without a rash or blisters on the child's hands or feet
• Meningitis
• Myopericarditis: inflammation and damage to the heart muscle and sac surrounding the heart, which can be caused by coxsackievirus B1, B2, and B5 infections
• Myositis: inflammation of a muscle, which can be caused by coxsackievirus infections
• Petechial and Purpuric Rashes: especially with coxsackievirus A9, which could get confused with Henoch-Schonlein purpura (HSP)
• Pleurodynia: sudden onset of chest pain caused by inflammation of the diaphragm and linked to a coxsackievirus infection
• Respiratory Illnesses: usually with a mild cough, runny nose, and sore throat and can be caused by coxsackievirus A21 and A24.

The coxsackievirus can also cause nonspecific febrile illnesses and a roseola-like illness—fever for two to three days followed by a rash for one to five days.

Surprisingly, the great majority of people with coxsackievirus infections have no symptoms at all, and there is no vaccine, cure, or treatment for coxsackievirus infections besides supportive care and treating symptoms. That sounds alarming, but fortunately, the most common coxsackievirus infections are not serious.

Getting and Avoiding Coxsackievirus Infections

Children can get sick about three to six days after being exposed to someone with a coxsackievirus infection (the incubation period). How do they get this virus?

Like many viral infections, the coxsackievirus is spread by both fecal-oral (direct or indirect contact with stool) and respiratory transmission (someone coughs or sneezes on you). They can also get these infections by touching a contaminated object (fomite).

For example, the CDC states that you might get infected by kissing someone who has the hand, foot, and mouth disease or by touching a doorknob that has viruses on it, then touching your eyes, mouth, or nose.

Still, because kids can shed the coxsackievirus in their stool and respiratory tract secretions (saliva and nasal secretions) for weeks after their symptoms have gone away or even without any symptoms, outbreaks can be hard to control or avoid.

That's probably why there are not strict guidelines to keep kids out of school and daycare when they have HFMD. For example the CDC states that "children should stay home while they have symptoms of hand, foot, and mouth disease" but they could still be shedding the virus. And in Texas, the Department of State Health Services says that kids with HFMD can go to school and daycare as long as they don't have a fever.

Regardless, handwashing, avoiding respiratory secretions, and disinfecting contaminated surfaces is more important than ever to help avoid getting sick and spreading these infections.

Facts to Know About Coxsackievirus

Other things to know about coxsackievirus infections include:

• Other countries sometimes see more severe cases of HFMD, often caused by enterovirus 71.
• Although complications from HFMD are rare, if you are pregnant and think you may have been exposed, the CDC recommends that you contact your healthcare provider.
• Studies have indicated that type 1 diabetes may be linked to previous coxsackievirus type B infections.
• Skin peeling on hands and feet and nail dystrophies can occur after coxsackievirus infections, especially coxsackievirus A6. The nail dystrophy ranges from developing Beau's lines (deep, horizontal grooves in a child's nails), nail breakage, to actually losing one or more nails and occurs one to two months after the primary infection.
• Testing can be done for most types of coxsackievirus, including by reverse transcriptase-polymerase chain reaction (PCR) assay and culture, but it is not something that can be routinely or quickly done in a pediatrician's office. It is typically not necessary either.
• Outbreaks of some coxsackievirus infections tend to occur in three to five-year cycles, while others circulate at low levels each year, especially in tropical climates. In other parts of the world, including the U.S., coxsackievirus infections are more common in summer and fall months.
• Having an infection with one coxsackievirus serotype doesn't give you immunity to any of the others, so you can, and likely will, get coxsackievirus infections multiple times in your life. Cross-reactivity between serotypes might offer some protection, though.