Rubella virus infection, also known as three-day or “German measles”, is a viral exanthematous infectious disease typically subclinical or mild disease in children and young adults. Symptomatology is generally characterized by fever, maculopapular rash accompanied by enlargement of lymph nodes. Infection during pregnancy, particularly the first trimester, can result in fetal death or severe anatomical deformity and mental retardation. Therefore, early detection of Rubella infection is extremely important. In a patient suffering from a primary rubella infection, the appearance of both IgG and IgM antibodies is associated with the appearance of clinical signs and symptoms when present. Serological evidence indicates that clinically unapparent or asymptomatic infections are common.
Serologically, IgM antibodies become detectable a few days after the onset of symptoms and reach peak levels at 7 – 10 days. The antibodies persist but rapidly diminish in concentration over the next 4 – 5 weeks until the antibody is no longer clinically detectable. Production of IgG increases rapidly for the next 7 to 21 days, then level off or even decrease in strength. IgG antibodies remain present and protective indefinitely.
The sensitivity, specificity, and reproducibility of Enzyme-Linked Immunosorbent Assays are comparable to other serological tests for antibody.