Immunoassay for the qualitative determination of IgM-antibodies against rubella virus
Rubella virus causes German measles, a mild rash disease which commonly occurs during childhood. It is highly contagious and mainly transmitted by the respiratory route.1 Rubella can also occur vertically from an infected mother to her child.1 Postnatal infection is rarely associated with complications, however, primary infection mainly during early pregnancy is a serious condition, as it may cause miscarriages or congenital rubella syndrome (CRS). CRS includes blindness, deafness, congenital heart disease and mental retardation1.
Today’s vaccination programs have considerably reduced the incidence of acute rubella and CRS2. Since rubella may present atypically or with non-specific symptoms and signs that may be caused by other viruses which do not have a teratogenic potential, it is important that the clinical diagnosis be confirmed by laboratory tests, particularly during pregnancy.3
The presence of IgM antibodies to rubella virus usually indicates an acute infection, but may also be unspecific or persistent4. After natural infection IgM antibodies may last for 1 – 3 months, while vaccination induced IgM antibodies stay longer (years) at low levels5. Seroconversion of specific rubella antibodies or a significant rise of the Rubella IgG antibody titer from a first to a second sample may further support the diagnosis of acute Rubella infection.3