Rubella

Rubella is the clinical manifestation of infection caused by the rubella virus, which was first isolated in 1962. The timing of infection before or after birth determines the two principal clinical syndromes. Infection in the postnatal period produces a relatively mild disease that is primarily notable for an erythematous rash (a rash caused by capillary congestion) and swollen lymph nodes. Infection during pregnancy can result in specific fetal anomalies defining the congenital rubella syndrome.

In postnatal infection (also known as German measles), the rash of rubella first appears on the face and spreads to the rest of the body. The rash consists of combined flat and raised (maculopapular) erythematous lesions that typically resolve after several days. A low-grade fever may be present. Swollen lymph nodes, particularly of the head and neck, have been commonly reported. Cough, sore throat, and headache may precede or accompany the appearance of rash. Complications of rubella infection in the post-natal period include joint complaints (arthritis and arthralgia), central nervous system infection (encephalitis), and a decrease in platelet number (thrombocytopenia). Joint complaints are more common in females than males and more frequent in older age groups (i.e., adolescents and adults).

Congenital rubella syndrome refers to specific birth defects caused by infection of the fetus with the rubella virus. Since the 1940s, it has been known that rubella infection in a pregnant woman could have adverse effects on the fetus. The risk to the fetus of developing congenital rubella syndrome is greatest when infection occurs early in the pregnancy. In congenital rubella syndrome, defects typically affect the eyes, ears, brain, and heart.

Between 1962 and 1965, an epidemic of rubella occurred in the United States. In 1964 alone, an estimated twenty to thirty thousand cases of congenital rubella syndrome occurred. A vaccine against rubella was licensed in the United States in 1969. Universal immunization against rubella has resulted in dramatic declines in both postnatal rubella and congenital rubella syndrome of over 97 percent. Between 1997 and 1999, only 792 cases of laboratory-confirmed ru-bella and 24 cases of congenital rubella syndrome were reported in the United States. The National Notifiable Diseases Surveillance System along with the National Congenital Rubella Syndrome Registry monitor the number of cases of congenital rubella syndrome.

At the start of the twenty-first century, cases of postnatal rubella and the congenital rubella syndrome occurred primarily because of lapses in vaccination. Prevention of congenital rubella syndrome requires that immunization rates remain high in order to prevent the spread of rubella in the community. Vaccination is aimed at children and at women of reproductive age who were not vaccinated as children. Children receive a first dose of rubella-containing vaccine (combined with mumps and measles vaccines as the MMR) at one year of age and a second dose between four and six years of age. In the United States, infants with congenital rubella syndrome are often born to mothers who emigrated from countries that do not routinely immunize against ru-bella. Because of this, women of reproductive age should be screened for immunity against the rubella virus (i.e., tested for the presence of antibodies against rubella, which indicates protection) during premarital and prenatal health-care visits.