Respiratory Syncytial Virus (RSV) Respiratory syncytial virus (RSV) was discovered in 1956 and has since been recognized as one of the most common causes of childhood illness. It is a respiratory virus that infects the lungs and breathing passages and causes mild, cold-like symptoms in healthy people. For infants and older adults, RSV can lead to serious illnesses such as bronchiolitis and pneumonia.
RSV is a member of the Paramyxoviridae family and the Pneumovirinae subfamily. It is an enveloped RNA virus and two strains (subgroups A and B) are recognized, the clinical significance of which is unclear. RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children younger than 1 year of age in the United States. Symptoms usually appear within 4 to 6 days of infection and healthy people usually recover in a week or two. When infants and children are exposed to RSV for the first time: • 25 to 40 out of 100 will have signs or symptoms of bronchiolitis or pneumonia • 5 to 20 out of 1,000 will require hospitalization (most children hospitalized for RSV infection are younger than 6 months of age)
RSV spreads from direct and indirect contact with nasal or oral secretions from infected people. The virus can survive on hard surfaces such as tables and crib rails for many hours, and on soft surfaces such as tissues and hands for shorter amounts of time. Researchers are developing an RSV vaccine, but none is available yet. There is no specific treatment for RSV. In the United States, 60% of infants are infected during their first RSV season, and nearly all children will have been infected with the virus by 2–3 years of age. RSV infections generally occur during fall, winter, and spring but the timing and severity of RSV circulation in a given community can vary from year to year.
DIAGNOSIS Several different types of laboratory tests are available for the diagnosis of an RSV infection including ELISA, rapid lateral flow, Direct Fluorescent Antibody Detection (DFA), neutralization assay and RT-PCR. Most clinical laboratories currently utilize EIA antigen detection tests, and many supplement antigen testing with cell culture or immunofluorescence assays to confirm diagnosis. Antigen detection tests and culture are generally reliable in young children but less useful in older children and adults. Because of its thermolability, the sensitivity of RSV isolation in cell culture from respiratory secretions can vary among laboratories. IgG and IgM antibody tests are used less frequently for routine diagnosis. Although useful for seroprevalence and epidemiologic studies, a diagnosis using paired acute- and convalescent-phase sera to demonstrate a significant rise in antibody titer to RSV cannot be made in time to guide patient care.
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ToRCH & Childhood Diseases- Reagents for Assay Development
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