– A mild, febrile, highly communicable viral disease characterized by a diffuse, punctate, macular rash.
Causes and Incidence
Rubella is caused by an RNA virus that is spread by airborne droplets or direct contact with nasopharyngeal secretions. The disease is communicable from a week before the rash appears to 5 days after the rash disappears. Rubella is common in childhood, but it also affects adults who were not infected during childhood. Infection confers lifelong immunity. Epidemics are seen during the spring of each year, and major epidemics occur in 6- to 9-year cycles. The incidence declined after the advent and widespread use of a vaccine in the 1960s, but it has been on the rise since 1988.
The virus invades the nasopharynx and travels to the lymph glands, causing lymphadenopathy. After 5 to 7 days it enters the bloodstream, causing a viremia and stimulating an immune response that results in a skin rash. The rash lasts about 3 days. Subclinical infection may remain for as long as 5 days after the rash disappears.
Swollen suboccipital, postauricular, and postcervical glands; fever, sore throat, cough, fatigue
Tiny reddish spots on the soft palate on the last day of prodrome or the first day of the rash; light pink to red, discrete, maculopapular rash that starts on the face and trunk and spreads to the upper and lower extremities
Headache, mild conjunctivitis
Complications include transitory arthritis, encephalitis, purpura, and congenital rubella syndrome. Congenital rubella syndrome occurs in an infant born to a woman who contracts rubella during the first trimesterof pregnancy. The result can be abortion, stillbirth, or congenital rubella. About 25% of exposed infants developthe syndrome and have such defects as cataracts, deafness, microcephaly, mental retardation, heart defects, hepato-splenomegaly, jaundice, and bone defects. Many die within 6 months of birth.
The diagnosis is made on the appearance of the rash plus a positive culture of pharyngeal secretions and a fourfold increase in specific antibodies.
Antipyretics for fever; active immunization in all people over 12 months of age with no evidence of immunity, except those who have a compromised immune system or are pregnant.
Isolation from pregnant women.