Rubella or German measles is a viral infection caused by the rubella virus. The disease is often mild and affects the skin and lymph nodes. It usually lasts up to three days and hence, is also known as three-day measles.
Causes of Rubella
Mostly prevalent in winter and spring, the rubella virus is transmitted by breathing in airborne droplets spread in the air when an infected person coughs or sneezes. Once inhaled, it replicates in the nose, throat and the lymph nodes. It then enters the blood within a week and spread to different organs. It may also be present in the urine. During pregnancy the virus may cross the placenta of the infected mother, infect the developing foetus and cause congenital rubella.
The incubation period of the virus ranges from 2 to 3 weeks, after which the distinctive red rash appears. An infected person is highly contagious from about a week before to a couple of weeks after the development of rash. But an infant with congenital rubella may continue to shed the virus for a year or more, and hence could be infectious for a longer time.
Symptoms of Rubella
Rubella is a mild disease with few or no symptoms, especially in young children. The classic symptom of the disease is a rash that appears first on the face and then spreads to the trunk and limbs. It may be accompanied by mild fever and swollen lymph nodes in the neck and behind the ears. The rash, sometimes itchy, typically fades in three days. Hence, the disease is also called as three-day measles. Few patients may have small, red spots (Forchheimer’s sign) on the soft palate preceding or along with the skin rash. Older children and adults may also have flu like symptoms such as stuffy or runny nose, headache, watery eyes, conjunctivitis, etc. Young women infected with rubella may also experience pain in the joints. Very rarely, ears and brain may be infected.
Infection of the mother by rubella virus during pregnancy can adversely affect the growing foetus. Infection during early pregnancy can cause miscarriages, stillbirths or severe birth defects in the baby. If a pregnant woman is infected in the first 20 weeks of gestation, especially in the first trimester, there is a risk of the baby being born with congenital rubella syndrome (CRS). CRS may include hearing impairment, eye defects (cataracts, retinopathy or congenital glaucoma), congenital heart disorders (most commonly patent ductus arterious and pulmonary artery stenosis) and mental retardation. Skin lesions of reddish-blue or magenta colour called blueberry muffin lesions may be usually present at birth. CRS may also cause low birth weight, thrombocytopenic purpura, anaemia, liver problems, etc.
Diagnosis of Rubella
A blood test to detect the presence of rubella virus specific IgM antibodies along with the characteristic symptoms can confirm the diagnosis. A nasal or throat swab may be used for the virus culture.
Treatment of Rubella
Treatment for Rubella is symptomatic. Mild symptoms usually do not require treatment. Medicines may be prescribed to relieve fever and pain. Pregnant women infected with the virus may be prescribed immune globulin. However, it doesn’t eliminate the risk of the baby becoming infected.
Treatment for congenital rubella syndrome is mainly supportive. The infants are screened for various defects and managed accordingly.
What are the chances of recovery from the disease?
Rubella is usually mild and self-limiting. Compared to adults, children have faster recovery. The rash subsides in three days and the swollen glands in seven to ten days. Joint pain can last for two to three weeks. An infection with rubella provides lifelong immunity to the disease. Pregnant women infected during the first trimester may have miscarriage or stillbirth. The baby may be born with birth defects.
Prevention of Rubella
Rubella can be prevented by vaccination. The MMR vaccine contains vaccine against measles, mumps and rubella. A single dose gives more than 95% long-lasting immunity. In India, the first dose is given at 15 to 18 months. The doctor might also advise a repeat dose of MMR at the age of 5 for added protection. Women planning to conceive should get tested for immunity to rubella. If tested negative, it is advisable for them to get vaccinated at least a month before conceiving. Vaccination is not recommended during pregnancy.
Infants with congenital rubella can shed the virus for up to 1 year of age. Hence, isolation is often recommended during the infectious period.
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