Rubella virus (family Togaviridae, genus Rubivirus ).
Person-to-person contact or droplets shed from the respiratory secretions of infected people. People may shed virus from 7 days before the onset of the rash to approximately 5–7 days after rash onset. Transmission from mother to fetus can also occur, with the highest risk of congenital rubella syndrome (CRS) if infection occurs in the first trimester. Infants with CRS can transmit virus for up to 1 year after birth.
Endemic rubella virus transmission was declared eliminated in the Americas in 2015; however, rubella virus continues to circulate widely, especially in Africa, the Middle East, and South and Southeast Asia. Globally, >100,000 infants are born each year with CRS, and >80% of those are born in Africa and some countries in South and Southeast Asia. In the United States, endemic rubella virus transmission was interrupted in 2001 and elimination was verified in 2004, but imported cases of both rubella and CRS continue to occur. From 2013 through 2015, a median of 6 (range, 5–9) imported cases were reported annually in the United States, and 3 CRS cases were reported during the same period.
Average incubation period is 14 days (range, 12–23 days). Usually presents as a nonspecific, maculopapular, generalized rash that lasts ≤3 days with generalized lymphadenopathy. Rash may be preceded by low-grade fever, malaise, anorexia, mild conjunctivitis, runny nose, and sore throat. Adolescents and adults, especially women, can also present with transient arthritis. Asymptomatic rubella virus infections are common. Infection during early pregnancy can lead to miscarriage, fetal death, or infants born with severe birth defects known as CRS.
Demonstration of specific rubella IgM or significant increase in rubella IgG in acute- and convalescent-phase specimens. RT-PCR can be used to detect virus infection; viral culture is also acceptable but is time-consuming and expensive. Rubella is a nationally notifiable disease.
All travelers aged ≥12 months who do not have acceptable evidence of immunity to rubella (documented by ≥1 dose of rubella-containing vaccine on or after the first birthday, laboratory evidence of immunity, or birth before 1957) should be vaccinated with measles-mumps-rubella (MMR) vaccine. Before departure from the United States, infants aged 6–11 months should receive 1 dose of MMR vaccine (for measles protection), and children aged ≥12 months and adults should receive 2 doses of MMR vaccine ≥28 days apart.
MMR vaccine is contraindicated during pregnancy. Pregnant women who do not have acceptable evidence of rubella immunity should not travel to countries where rubella is endemic or areas with known rubella outbreaks, especially during the first 20 weeks of pregnancy, and should be vaccinated immediately postpartum. Health care providers should also ensure that all women of childbearing age and recent immigrants are up-to-date on their immunization against rubella or have evidence of immunity to rubella, because these groups are at the highest risk for maternal–fetal transmission of rubella virus, which can result in CRS.
CDC website: www.cdc.gov/rubella
Michelle Morales, Tatiana Lanzieri, Susan E. Reef