Rubella (Viral Disease)

Description

Rubella is an acute viral disease that can affect susceptible persons of any age. Although generally a mild rash illness, if contracted in the early months of pregnancy, rubella is associated with a high rate of fetal wastage or birth defects, known as congenital rubella syndrome (CRS).

Occurrence

The largest annual total number of cases of rubella in the United States occurred in 1969, when 57,686 cases were reported. Following vaccine licensure in 1969, rubella incidence fell rapidly. Since 1992, <500 cases have been reported each year. However, the proportion of reported rubella cases among adults 20 years of age or older has risen steadily, from 29% in 1991 to 71% in 2000. Since 1992, an average of six CRS cases has been reported annually. Most persons 20-30 years of age with rubella, as well as mothers of most infants with CRS, were born outside the United States in countries where routine rubella vaccination programs are not used or have only recently been implemented.

Risk for Travelers

Rubella occurs worldwide, and the risk of exposure to rubella outside the United States can be high. Although more than half of all countries now use rubella vaccine, rubella still remains a common disease in many parts of the world.

Prevention

Rubella vaccine contains live, attenuated rubella virus. It is available as a single-antigen preparation or combined with live, attenuated measles or mumps vaccines, or both. Combined measles, mumps, and rubella (MMR) vaccine is recommended whenever one or more of the individual components is indicated.

Although vaccination against measles, mumps, or rubella is not a requirement for entry into any country (including the United States), persons traveling or living abroad should ensure that they are immune to all three diseases. Immunity to rubella is particularly important for health-care providers, pregnant women, and all women of childbearing age. Persons can be considered immune to rubella if they have documentation of receipt of one or more doses of a rubella-containing vaccine on or after their first birthday, or laboratory evidence of rubella immunity. Birth before 1957 provides only presumptive evidence of rubella immunity and does not guarantee that a person is immune. Rubella can occur in susceptible persons born before 1957, and CRS can occur in the offspring of women born before 1957 infected with rubella during pregnancy. The Advisory Committee on Immunization Practices (ACIP) recommends that birth before 1957 not be accepted as evidence of rubella immunity for women who might become pregnant. A clinical diagnosis of rubella is unreliable and should not be considered in assessing immune status. Because many rash illnesses can mimic rubella infection and many rubella infections are unrecognized, the only reliable evidence of previous rubella infection is the presence of serum rubella IgG.

The first dose of MMR should be routinely administered to infants 12-15 months of age. A single dose of MMR vaccine induces antibody formation to all three viruses in at least 95% of susceptible persons vaccinated at 12 months of age or older. The second dose should be separated from the first dose by a minimum of 28 days. (See Vaccine Recommendations for Infants and Children, for a discussion of the rubella immunization schedule modifications for infants who will be traveling.)

Health-care providers who treat women of childbearing age should routinely determine their rubella immunity status and vaccinate those who are susceptible and not pregnant. Proof of immunity can be either a verified record of vaccination or a positive IgG antibody serologic test. Rubella-susceptible women who 1) do not report being pregnant, 2) are not likely to become pregnant within 1 month, and 3) have no other contraindicating conditions should be vaccinated. Before vaccination, each patient should be counseled to avoid pregnancy for 1 month after vaccination because of the theoretical risk for vaccine virus affecting the fetus. Because routine pregnancy screening is not recommended before rubella vaccination, patients should be counseled regarding the theoretical risk to the fetus from inadvertent vaccination of a pregnant woman.

Adverse Reactions

Refer to Travelers' Health Information on Measles (Rubeola), for information on adverse reactions following MMR vaccine.

Precautions and Contraindications

Refer to Travelers' Health Information on Measles (Rubeola), for information on precautions and contraindications for MMR vaccine.

Health Information for International Travel 2003-2004