Laboratory diagnosis of congenital and maternal rubella infection: a review.

Physicians are aware of the congenital rubella syndrome. Serodiagnosis is usually used to detect rubella infection in pregnant women and their fetuses. Although being considered the cornerstone of serodiagnosis, the hemagglutination inhibition test is gradually being replaced by new more convenient methods. Tests to detect IgM eliminate the need for paired sera to diagnose acute rubella infection. However, because of the possibilities of false positive, IgM results should be interpreted with caution. Detection of IgM in cord blood and new genetic technology made the diagnosis of infection in utero possible. The evidence of reinfection in people considered to be immune is abundant; however, discovering new antigenic determinants correlating with immunity may solve the problem and a new vaccine and antibody test that is truly associated with immunity will be available in the future.