RUBELLA IGM AB 0004422

Rubella is an acute exanthematous viral infection of children and adults. Rash, fever and lymphadenopathy characterize the illness. While many infections are subclinical, this virus has the potential to cause fetal infection with resultant birth defects. In the absence of a current or recent infection, a demonstration of specific IgG on a serum sample is evidence of immunity to rubella. A positive rubella IgM result does not necessarily indicate current or recent infection. Without a history of exposure to rubella or symptoms consistent with rubella, the IgM result may be difficult to interpret. Rubella IgM can be false positive due to other causes (e.g., parvovirus, rheumatoid factor, cytomegalovirus). Rubella IgM may also persist for more than 12 months after vaccination or natural infection. For a serologic diagnosis of congenital rubella in the neonatal period, antibody to rubella virus should be measured in both infant and maternal sera. If IgM is detected in a newborn infants serum, it is probable that transplacental rubella infection has occurred.