Cause: Rubella virus, a togavirus, genus Rubivirus.
Illness and treatment: Acquired rubella or postnatal rubella is rubella disease contracted after birth; this is to differentiate it from congenital rubella syndrome as described below. Rubella is also known as German measles or 3-day measles although it is not caused by the measles virus. Rubella is usually a mild disease with fever, swollen lymph nodes and a maculopapular rash which usually starts on the face, becoming generalized within about 24 hours. Most cases of rubella are subclinical with up to half of infections being asymptomatic. Older children and adults may have a 1-to-5-day prodrome of malaise, lymph node swelling, and upper respiratory symptoms before the rash. Transient arthritis and arthralgia can occur in adults, particularly in women, but is rarely seen in children. Complications including encephalitis (1 in 6000 cases) and thrombocytopenia (1 in 3000 cases) are rare.
Congenital rubella syndrome (CRS) can result if a woman acquires rubella during pregnancy and is of greatest danger to the fetus. Up to 90% of infants born to mothers who are infected with rubella during the first trimester of pregnancy will develop CRS. CRS can cause a spectrum of physical anomalies including hearing impairment, cataracts, heart defects, liver and spleen damage, low birth weight, developmental delays and behavioral disorders. Some effects may not be apparent at birth. CRS can also result in miscarriage (the loss of a fetus within 20 weeks of conception) or stillbirth (the death of a fetus after 20 weeks of pregnancy).
Sources: Humans are the reservoir. Infants with CRS can shed virus for an extended period, but a true carrier state does not occur.
Additional risks: Transmission is through airborne or droplet spread of the respiratory secretions of infected persons, including asymptomatic and subclinical infections. Infants with CRS can shed the virus for an extended period, but a true carrier state does not occur. This includes asymptomatic and subclinical infections.
Prevention: Vaccination with one dose of the MMR vaccine is about 97% effective at preventing rubella. The MMR vaccine is not effective at preventing infection in people already infected with the rubella virus.
Recent Washington trends: Between 2001 and 2023, a total of seven cases of rubella were reported in Washington state, with the last case occurring in 2013. Since the year 2001, only 0 to 2 cases of acquired rubella have been reported annually in Washington State.
Source: 2023 Communicable Disease Annual Report
In 2004, rubella was declared eliminated in the United States. Rubella elimination is defined as the absence of ongoing disease ongoing transmission for 12 months or more in a specific geographic area (e.g. the United States). Since elimination was declared, most reported rubella cases have been in individuals who were infected while living or traveling outside the country and their close contacts. Currently, fewer than 10 cases of acquired rubella are reported in the United States each year.
Purpose of Reporting and Surveillance
- To prevent congenital rubella syndrome (CRS)
- To assure that children with suspected CRS are tested to confirm or rule out the diagnosis in a timely manner in order to assure prompt treatment and prevent spread of the disease.
- To assure that acquired rubella cases are tested to confirm or rule out the diagnosis. (As part of the proposed Healthy People 2010 objectives, a goal was established to eliminate U.S.-acquired rubella and CRS in the United States by the year 2010).
- To identify exposed pregnant women in a timely manner, determine their susceptibility and infection status, and provide appropriate counseling about the risk of fetal infection.
- To evaluate the effectiveness of disease prevention efforts such as immunization.
Legal Reporting Requirements
- Health care providers and health care facilities: immediately notifiable to local health jurisdiction (acute disease only)
- Laboratories: immediately notifiable to local health jurisdiction; submission required – isolate or if no isolate available, specimen associated with positive result, within 2 business days; submission on request – other specimen, within 2 business days.
- Local health jurisdictions: notifiable to the Washington State Department of Health (DOH) Communicable Disease Epidemiology (CDE) within 7 days of case investigation completion or summary information required within 21 days.