The Rubella virus is a member of the Togoviridae family of viruses and is a completely different virus from Measles, though the disease is called German Measles, or Rubella. It causes a mild disease in children and young adults, a rash and fever that lasts 2 to 3 days. However, unseen complications can occur in pregnant women, resulting in birth defects.
Rubella Communicability
The virus is spread by coughing and sneezing in proximity to other people. The incubation period is 12-23 days. Asymptomatic infections, those that never manifest physically, occur in 20-50% of cases. The infected person is most contagious when the rash is erupting, but transmission can occur a week before the rash appears to 5-7 days after its appearance.
Rubella Infection
The physical manifestations of rubella include rash and fever, lymphadenopathy (swollen lymph nodes), red watery eyes (conjunctivitis), and fatigue or malaise. Fewer than 70% of infected women experience arthritis and joint pain. Rare complications include encephalitis and nerve inflammation. About 25% of babies born to mothers who had the infection during the first trimester are born with one or more birth defects, called congenital rubella syndrome. It is estimated that 20% of women are susceptible to the disease.
Congenital Rubella Syndrome
A blood test can determine if a person is immune to rubella. The March of Dimes recommends this test for women wanting or planning on becoming pregnant. Those who are not immune are recommended to be vaccinated at least 28 days prior to becoming pregnant. The testing usually occurs at early prenatal visits, but vaccination is not recommended after becoming pregnant and avoiding the infection is all a mother-to-be can do. Those with other children in the household are particularly susceptible to coming into contact and should have their children vaccinated.
The birth defects seen in children born to mothers infected with rubella include heart defects, mental handicaps, hearing loss, eye defects, and movement disorders.
German Measles Prevention
The MMR (measles – mumps – rubella) or MMRV (MMR plus varicella) vaccine is administered to prevent rubella, as it contains a weakened rubella virus. A preservative developed in the 1930s, thimerosal, has not been in the vaccines since 2001, and the Merck version of the vaccine (MMRII) has never contained the preservative. There was some controversy in recent years about an association with autism and the mercury-based preservative, but the original data by Wakefield was found to be fabricated and no other study has confirmed the findings.
The first vaccine dose is given between 12 and 15 months age, and the booster can be given 4 weeks later or before the start of Kindergarten at 4-6 years of age. Some immunocompromised children may not be able to receive the vaccine, they should be protected from disease if approximately 90% of their peers are vaccinated (called herd immunity). A monovalent vaccine is also available.
Vaccine Side Effects
Less than one-fourth of those who are vaccinated with MMR will be susceptible to side effects, which include a fever and rash 1-2 weeks after receiving the injection. One per 1,000,000 vaccinations will have an allergic reaction. The more common side effect is lymph swelling, a side effect of the immune response. Low platelet counts occur 1 per 100,000 vaccinations in the U.S. Neurological side effects are considered coincidental but should be treated to determine the cause.
For more information on other diseases protected against by MMR, read about Mumps.
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