- Rubella is a contagious, generally mild viral infection that occurs most often in children and young adults.
- Rubella infection in pregnant women may cause fetal death or congenital defects known as congenital rubella syndrome (CRS).
- Worldwide, an estimated 110 000 babies are born with CRS every year.
- There is no specific treatment for rubella but the disease is preventable by vaccination.
Rubella is an acute, contagious viral infection. While the illness is generally mild in children, it has serious consequences in pregnant women causing fetal death or congenital defects known as congenital rubella syndrome (CRS).
The rubella virus is transmitted by airborne droplets when infected people sneeze or cough. Humans are the only known host.
In children, the disease is usually mild, with symptoms including a rash, low fever (<39°C), nausea and mild conjunctivitis. The rash, which occurs in 50–80% of cases, usually starts on the face and neck before progressing down the body, and lasts 1–3 days. Swollen lymph glands behind the ears and in the neck are the most characteristic clinical feature. Infected adults, more commonly women, may develop arthritis and painful joints that usually last from 3–10 days.
Once a person is infected, the virus spreads throughout the body in about 5-7 days. Symptoms usually appear two to three weeks after exposure. The most infectious period is usually 1–5 days after the appearance of the rash.
When a woman is infected with the rubella virus early in pregnancy, she has a 90% chance of passing the virus on to her fetus. This can cause miscarriage, stillbirth or severe birth defects known as CRS. Infants with CRS may excrete the virus for a year or more.
Congenital rubella syndrome
Children with CRS can suffer hearing impairments, eye and heart defects and other lifelong disabilities, including autism, diabetes mellitus and thyroid dysfunction – many of which require costly therapy, surgeries and other expensive care.
The highest risk of CRS is in countries where women of childbearing age do not have immunity to the disease (either through vaccination or from having had rubella). Before the introduction of the vaccine, up to four babies in every 1000 live births were born with CRS.
Large-scale rubella vaccination during the past decade has practically eliminated rubella and CRS in many developed and in some developing countries. The WHO Region of the Americas has had no endemic (naturally-transmitted) cases of rubella infection since 2009.
CRS rates are highest in the WHO African and South-East Asian regions where vaccine coverage is lowest.
The rubella vaccine is a live attenuated strain that has been in use for more than 40 years. A single dose gives more than 95% long-lasting immunity, which is similar to that induced by natural infection.
Rubella vaccines are available either in monovalent formulation (vaccine directed at only one pathogen) or more commonly in combinations with other vaccines such as with vaccines against measles (MR), measles and mumps (MMR), or measles, mumps and varicella (MMRV).
Adverse reactions following vaccination are generally mild. They may include pain and redness at the injection site, low-grade fever, rash and muscle aches. Mass immunization campaigns in the Region of the Americas involving more than 250 million adolescents and adults did not identify any serious adverse reactions associated with the vaccine.