Rubella
Definition
Rubella, also called German measles or three-day measles, is a highly contagious viral disease that in most children and adults causes mild symptoms of low fever , swollen glands, joint pain , and a fine red rash. Although rubella causes only mild symptoms in child and adult sufferers, the infection can have severe complications for the fetus of a woman who becomes infected with the virus during the first trimester of pregnancy. These complications include severe birth defects or death of the fetus.
Description
Rubella is spread through contact with fluid droplets expelled from the nose or throat of an infected person. A person infected with the rubella virus is contagious for about seven days before any symptoms appear and continues to be able to spread the disease for about four days after the appearance of symptoms. Rubella has an incubation period of 12 to 23 days.
Although rubella is generally considered a childhood illness, people of any age who have not been vaccinated or previously caught the disease can become infected. Having rubella once or being immunized against rubella normally gives lifetime immunity. For this reason vaccination is highly effective in reducing the number of rubella cases.
Women of childbearing age who do not have immunity against rubella should be particularly concerned about getting the disease. Rubella infection during the first three months of pregnancy can cause a woman to miscarry or cause her baby to be born with birth defects. Although it has been practically eradicated in the United States, rubella is still common in less developed countries because of poor immunization penetration, creating a risk to susceptible travelers. Some countries have chosen to target rubella vaccination to females only and outbreaks in foreign-born males have occurred on cruise ships and at U.S. summer camps.
Demographics
Although rubella was once a common childhood illness, its occurrence has been drastically reduced since vaccine against it became available in 1969. According to statistics for 1964–1965, prior to routine rubella immunization in the United States, there were 2,100 newborn deaths and 11,250 miscarriages attributed to rubella infection of pregnant women. In addition, about 20,000 infants were born with birth defects attributable to rubella infection in utero. Of these babies, 11,600 were born deaf; 3,580 were born blind; and 1,800 suffered severe developmental delay . In the 20 years following the introduction of the vaccine, reported rubella cases dropped 99.6 percent. In 2000, there were only 152 reported cases of rubella infection and seven reported cases of congenital rubella.
Causes and symptoms
Rubella is caused by the rubella virus ( Rubivirus ). Symptoms are generally mild, and complications are rare in anyone who is not pregnant.
The first visible sign of rubella is a fine red rash that begins on the face and rapidly moves downward to cover the whole body within 24 hours. The rash lasts about three days, which is why rubella is sometimes called the three-day measles. A low fever and swollen glands, especially in the head (around the ears) and neck, often accompany the rash. Joint pain and sometimes joint swelling can occur, more often in women. It is quite common to get rubella and not show any symptoms (subclinical infection).
Symptoms disappear within three to four days, except for joint pain, which may linger for a week or two. Most people recover fully with no complications. However, severe complications may arise in the unborn children of women who get rubella during the first three months of their pregnancy. These babies may be miscarried or stillborn. A high percentage is born with birth defects. Birth defects are reported to occur in 50 percent of women who contract the disease during the first month of pregnancy, 20 percent of those who contract it in the second month, and 10 percent of those who contract it in the third month.
The most common birth defects resulting from congenital rubella infection are eye defects such as cataracts, glaucoma, and blindness; deafness; congenital heart defects; and mental retardation . Taken together, these conditions are called congenital rubella syndrome (CRS). The risk of birth defects drops after the first trimester, and by the twentieth week, there are rarely any complications.
Diagnosis
The rash caused by the rubella virus and the accompanying symptoms are so similar to other viral infections that it is impossible for a physician to make a confirmed diagnosis on visual examination alone. The only sure way to confirm a case of rubella is by isolating the virus with a blood test or in a laboratory culture.
A blood test is done to check for rubella antibodies. When the body is infected with the rubella virus, it produces both immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to fight the infection. Once IgG exists, it persists for a lifetime, but the special IgM
All pregnant women should be tested for rubella early in pregnancy, whether they have a history of vaccination. If the woman lacks immunity, she is counseled to avoid anyone with the disease and to be vaccinated after giving birth.
Treatment
There is no drug treatment for rubella. Bed rest, fluids, and acetaminophen for pain and temperatures over 102°F (38.9°C) are usually all that is necessary.
Babies born with suspected CRS are isolated and cared for only by people who are sure they are immune to rubella. Congenital heart defects are treated with surgery.
Prognosis
Complications from rubella infection are rare in children, pregnant women past the twentieth week of pregnancy, and other adults. For women in the first trimester of pregnancy, there is a high likelihood of the child being born with one or more birth defect. Unborn children exposed to rubella early in pregnancy are also more likely to be miscarried, stillborn, or have a low birth weight. Although the symptoms of rubella pass quickly for the mother, the consequences to the unborn child can last a lifetime.
Prevention
Vaccination is the best way to prevent rubella and is normally required by law for children entering school. Rubella vaccine is usually given in conjunction with measles and mumps vaccines in a shot referred to as MMR (mumps, measles, and rubella). Children receive one dose of MMR vaccine at 12 to 15 months and another dose at four to six years.
Pregnant women should not be vaccinated, and women who are not pregnant should avoid conceiving for at least three months following vaccination. As of 2004, however, accidental rubella vaccinations during pregnancy had not clearly been associated with the same risk as the natural infection itself. Women may be vaccinated while they are breastfeeding. People whose immune systems are compromised, either by the use of drugs such as steroids or by disease, should discuss possible complications with their doctor before being vaccinated.
KEY TERMS
Incubation period —The time period between exposure to an infectious agent, such as a virus or bacteria, and the appearance of symptoms of illness. Also called the latent period.
Trimester —The one of three periods of about 13 weeks each into which a pregnancy is divided.
Parental concerns
While rubella infection in an older child or adult is rarely complicated, the risks of not immunizing a child against rubella are highest in the unborn. Congenital rubella is a serious, life-changing condition, and adherence to immunization recommendations is crucial to the public health.
Resources
BOOKS
Maldonado, Yvonne A. "Rubella Virus." In Principles and Practice of Pediatric Infectious Diseases , 2nd ed. Edited by Sarah S. Long et al. St. Louis, MO: Elsevier, 2003.
Thompson, George H. "The Neck." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.
ORGANIZATIONS
March of Dimes Birth Defects Foundation. 1275 Mamaroneck Ave., White Plains, NY 10605. Web site: http://www.modimes.org.
National Organization for Rare Disorders. PO Box 8923, New Fairfield, CT 06812-8923. Web site: http://www.rarediseases.org.
Tish Davidson, A.M. Rosalyn Carson-DeWitt, MD
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