Coxsackie Virus

What is Coxsackie virus?

Coxsackie virus is a member of the Picornaviridae family of viruses in the genus termed Enterovirus. Coxsackie viruses are subtype members of Enterovirus that have a single strand of ribonucleic acid (RNA) for its genetic material. The Enteroviruses are also referred to as picornaviruses (pico means "small," so, "small RNA viruses"). Coxsackie virus was first isolated from human feces in the town of Coxsackie, New York, in 1948 by G. Dalldorf. Coxsackie virus is also written as coxsackievirus.

What are the types of Coxsackie viruses, and what can they cause?

Coxsackie viruses are separable into two groups, A and B, which are based on their effects on newborn mice (Coxsackie A results in muscle injury, paralysis, and death; Coxsackie B results in organ damage but less severe outcomes.) There are over 24 different serotypes of the virus (having distinct proteins on the viral surface). Coxsackie viruses infect host cells and cause host cells to break open (lyse).
Type A viruses cause herpangina (painful blisters in the mouth, throat, hands, feet, or in all these areas). Hand, foot, and mouth disease (HFMD) is the common name of this viral infection. Coxsackie A 16 causes the majority of HFMD infections in the U.S. It usually occurs in children (age 10 and under), but adults can also develop the condition. This childhood disease should not be confused with the "foot and mouth disease" usually found in animals with hooves (for example, cattle, pigs, and deer). Type A also causes conjunctivitis (inflammation of the eyelids and white area of the eye).
Type B viruses cause epidemic pleurodynia (fever, lung, and abdominal pain with headache that lasts about two to 12 days and resolves). Pleurodynia is also termed Bornholm disease. There are six serotypes of Coxsackie B (1-6, with B 4 considered by some researchers as a possible cause of diabetes in a number of individuals).
Both types of viruses (A and B) can cause meningitis, myocarditis, and pericarditis, but these occur infrequently from Coxsackie infections. Some researchers suggest Coxsackie virus (mainly Coxsackie B4) has a role in the development of acute onset type I (formerly known as juvenile) diabetes, but this relationship is still under investigation.

What are the signs and symptoms of Coxsackie virus infection?

The most frequent signs and symptoms of Coxsackie viral infections start with fever, sore throat, malaise (feeling tired), and a poor appetite. This incubation period lasts about one to two days. Sore areas in the mouth develop in about a day or two after the initial fever and develop into small blisters that often ulcerate. Many infected people (usually children 10 years of age and younger) go on to develop a rash that itches on the palms of the hands and the soles of the feet. Other areas such as the buttocks and genitals may be involved. These symptoms usually last about seven to 10 days and the person recovers completely. The individuals are most contagious for about a week after symptoms begin, but because the virus can be shed by the infected individual sometimes for weeks after the symptoms have gone away, the person may be mildly contagious for several weeks. The last two references show pictures of the blisters.
Infrequently, the infection may result in temporary fingernail or toenail loss (termed onychomadesis). Rarely, the disease may progress to cause viral meningitis (headache, stiff neck), myocarditis (heart muscle infection), pericarditis (inflammation/fluid collection of the tissue surrounding the heart), or encephalitis (brain swelling).

How do people get infected with Coxsackie virus, and what are the risk factors?

Infection usually is spread by fecal-oral contamination, although occasionally the virus is spread by droplets expelled by infected individuals. Items like utensils, diaper-changing tables, and toys that come in contact with body fluids that contain the virus may also transmit them to other individuals. Although people of any age can get infected, the majority of patients identified with Coxsackie infection are children. Pregnant women can pass Coxsackie virus to their newborns, which may cause serious problems for the newborn, so pregnant women need to notify their obstetrician if they exhibit symptoms of the infection, especially if they are near their delivery date.
Risk factors for Coxsackie virus infection include physical contact with any patient with individuals with HFMD symptoms. Infectious virus can be found in feces, saliva, fluid in blisters, and nasal secretions. Even patients who have recovered and have no symptoms may still shed infectious virus for weeks.

How are Coxsackie virus infections diagnosed?

Patients are usually diagnosed by their clinical appearance. Clinically, blisters that are painful usually on the hands, feet, and mouth in a child with fever are considered diagnostic of Coxsackie virus infection. However, in rare instances, viral tests can be done to identify the virus, but the tests are expensive, usually need to be sent to a specialized viral diagnostic laboratory and often take about two weeks to get a result. This testing is almost never done since most infections are self-limited and typically mild.

Is there any treatment for Coxsackie virus infection?

There is no specific treatment for this typically self-limited disease (the symptoms resolve without specific antiviral treatment in about two to 10 days). However, symptomatic treatment (acetaminophen [Tylenol]) that reduces fever and discomfort is currently recommended. Mouthwashes and sprays may lessen the oral discomfort. Fluids are also suggested to prevent dehydration, however, acidic juices may irritate the mouth ulcers. Cold milk may sooth the oral discomfort. Some physicians use topical diphenhydramine (Benadryl) containing gel or liquids to treat the hand and foot discomfort.
The relatively rare complications of Coxsackie virus infections (for example, heart or brain infection) require special individualized treatments usually administered by an infectious disease consultant.

Can Coxsackie virus infections be prevented?

Prevention of Coxsackie virus infections is difficult but possible. With children, keeping strict hygienic precautions is almost impossible, but good practices such as hand washing after diaper changing or touching infected skin may reduce viral transmission to other family members. Attempts to regularly clean items that children contact, especially toys, pacifiers, and any items they may place in their mouths, may also reduce viral transmission. Hand washing, in general, is the best prevention technique. Currently, there is no vaccine available.
Pregnant women should avoid contact with children (or adults) with HFMD because some studies suggest that Coxsackie virus may cause developmental and other defects in the fetus.
Although infection and resolution of the disease usually renders the person immune to reinfection with the viral type that initiated the disease, the person is not immune to other Coxsackie viral types. For example, a person may become immune to Coxsackie viral type B4 but still would be susceptible to all of the other Coxsackie viral types. In addition, other viruses such as Enterovirus 71 and enteric cytopathic human orphan (ECHO) viruses can produce HFMD symptoms. Consequently, it is possible for some people to have multiple infections with HFMD symptoms, even though repeated infections occur infrequently.

What are other sources of information about Coxsackie virus?

"Viral Infections and Pregnancy," eMedicine
http://emedicine.medscape.com/article/
235213-overview
"Hand-Foot-and-Mouth Disease," eMedicine
http://emedicine.medscape.com/article/
1132264-overview
"Hand, Foot, & Mouth Disease (HFMD)," Centers for Disease Control and Prevention
http://www.cdc.gov/ncidod/dvrd/revb/
enterovirus/hfhf.htm
http://embryology.med.unsw.edu.au/
Defect/images/Coxsackie_B4_virus.jpg

Coxsackie Virus At A Glance

• Coxsackie viruses are RNA viruses that may cause hand, foot, and mouth disease (HFMD).
• HFMD usually occurs in children but can occur in adults; the majority of infections are self-limited so no treatment is required.
• HFMD, caused by Coxsackie viruses, usually cause fever, malaise, rash, and small blisters that ulcerate. The most frequent locations for the blisters/ulcers are on the palms of the hand, soles of the feet, and in the mouth.
• HFMD usually resolves in about 10 days with no scarring, but the person may shed Coxsackie virus for several weeks.
• Although lab tests for Coxsackie viruses can be done, the vast majority of infections are diagnosed by clinical features (HFMD blisters/ulcers).
• There is no specific treatment or vaccine available for Coxsackie virus infections.
• Prevention is difficult; avoid direct contact with anyone with HFMD, and their stool, saliva, and blister fluid. Hand washing and cleaning of items handled by HFMD patients are the best methods for prevention.

REFERENCES:

Blomqvist, S., P. Kemola, P., S. Kaijalainen, et al. "Co-circulation of Coxsackieviruses A6 and A10 in Hand, Foot and Mouth Disease Outbreak in Finland." J. Clin. Virol. 48.1 May 2010: 49-54.

Richer, M., and M. Horwitz. "Coxsackievirus Infection as an Environmental Factor in the Etiology of Type 1 Diabetes." Autoimmun. Rev. 8.7 June 2009: 611-615.

Medical Author:

Charles Patrick Davis, MD, PhD

Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

Source:Medicinenet.com.