ToRCH & Childhood Diseases

Coxsackie Coxsackievirus is a member of the Picornaviridae family of viruses and are subtype members of Enteroviruses. In cooler climates, outbreaks of coxsackie virus often occur in the summer and fall, though they can cause infections year-round in tropical parts of the world.

Coxsackieviruses spread from person to person, usually on unwashed hands of surfaces contaminated by feces. In most cases, coxsackieviruses cause mild flu-like symptoms and go away without treatment. But in some cases, and especially in infants, infections can lead to more serious diseases such viral meningitis, encephalitis and myocarditis. There are two groups of coxsackie viruses which are divided based on their effects on newborn mice: coxsackie A, which results in muscle injury, paralysis, and death; and coxsackie B, which results in organ damage but overall has less severe outcomes. In total, there are 24 different serotypes of the virus and each serotype has distinct proteins on its viral surface. The most well known coxsackie A disease is hand-foot and-mouth disease (HFMD), a common childhood illness which affects mostly children aged 5 or under, and it is often from infection by coxsackie A16 or A6. Other diseases include acute haemorrhagic conjunctivitis (coxsackie A24 specifically), herpangina, and aseptic meningitis (both coxsackie A and B viruses). Coxsackievirus A7 can also cause polio-like permanent paralysis. There are six types of coxsackie B (B1-B6) and they tend to infect the heart, pleura, pancreas, and liver, causing pleurodynia, myocarditis, pericarditis,

Source: www.drugline.org

and hepatitis. Specifically coxsackie B2 and B5 viruses have been implicated in HFMD as well as respiratory infection and the B4 strain of coxsackievirus has been discovered to be a possible cause of diabetes mellitus type 1. Both group A and group B coxsackie viruses can cause nonspecific febrile illnesses, rashes, upper respiratory tract disease, and aseptic meningitis.

DIAGNOSIS Neutralization tests are generally the best serological tests available for coxsackieviruses, however they are labor intensive and take at least 3 days before the results are available. Antibody titers are compared in paired sera, the first collected within 5 days of onset of symptoms and the second some days later and a significant rise in titer is evidence for a recent infection. More recently, IgM capture assays have become available for various coxsackie A and B, and echovirus serotypes. However, cross-reactivity between the IgM responses to different enteroviruses, including hepatitis A, often occurs. The older the patient, the more likely such heterotypic responses will take place. Enterovirus IgM usually lasts 8- 12 weeks but may persist longer in some patients. It has been suggested that a prolonged response of a few years may indicate a persistent infection in cases of recurrent pericarditis. Approximately 30- 40% of patients with myocarditis, 60- 70% of patients with aseptic meningitis, and 30% of patients with postviral fatigue syndrome give positive results for coxsackie B IgM. However, 10% of normal adults will also give a positive result, perhaps having experienced a recent enterovirus infection.

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ToRCH & Childhood Diseases- Reagents for Assay Development

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