Monday, August 15, 2011

Mumps Laboratory diagnosis

Virus isolation from saliva is most successful during first 4- 5 days of symptoms. Virus is recovered from urine for up to 2 weeks after symptoms begin, especially if concentrate the virus by centrifugation. In patients with meningitis, the CSF can be expected to yield virus in, at best, about half of samples taken within 8 - 9 days of the onset of CNS disease. Monkey kidney primary or cell lines may be used for isolation. Not all mumps virus isolates show characteristic syncytial CPE. Therefore, hemadsorption techniques should be applied to all cultures before they are discarded as negative. Immunofluorescence techniques provide direct confirmation of the isolation of a hemagglutinating virus in the culture (Knowles and Jin, 2005).

Haemadsorption of erythrocytes on the surface of cells infected with mumps virus (Stannard, 1996)
• Serology
Comparison of mumps-specific antibody titers from serum taken at the onset of clinical disease and a convalescent serum sample obtained 2 to 4 weeks later usually shows the anticipated rise in CF, HI. Determination of virus-specific IgM and IgG levels on a single acute-phase serum provides an alternative when paired sera are not available. The current standard for relatively specific, rapid, and cost-effective serologic diagnosis is ELISA (Chomell et al., 1997).
• Molecular detection
Combinations of techniques, such as amplifying live virus in clinical samples via Vero cell co-cultivation, followed by RT-PCR amplification of virus genome, can provide a sensitivity of 1 - 20 units of infectious virus per milliliter (Boriskin et al., 1993).

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