by Hal B. Jenson, M.D.
Chief, Pediatric Infectious Diseases
University of Texas Health Science Center
San Antonio, TX
and
by Charles T. Leach, M.D.
Associate Professor of Pediatrics
University of Texas Health Science Center
San Antonio, TX
What is rubella?
Rubella-also commonly known as German measles or, sometimes, three-day measles because
of the characteristic duration of the rash-is usually a mild and frequently inapparent
infectious disease in children and adults.
A rubella infection during the first trimester of pregnancy can result in miscarriage,
stillbirth, or infants with a pattern of birth defects known as "congenital rubella
syndrome." Congenital rubella syndrome can result in many severe symptoms in the
newborn, including poor growth, cataracts, deafness, and heart defects.
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What causes rubella?
The rubella virus, an RNA virus of the rubellavirus family of viruses, causes rubella.
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Who gets rubella?
Rubella was an important disease that occurred in almost all children before the
introduction of the rubella vaccine. Rubella is highly contagious, and it has historically
caused large outbreaks. The last epidemic of rubella in the United States occurred
in 1964, and resulted in more than 20,000 infants being born with congenital rubella
syndrome. Rubella is now very uncommon in the United States. Since licensure of
the rubella vaccine in 1969, the incidence of rubella has decreased from an average
of more than 47,000 reported cases annually to only 345 cases in 1998, with only
5 cases of congenital rubella syndrome.
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How does the rubella virus cause disease?
The rubella virus is transmitted from person-to-person by direct contact or by contaminated
secretions of the nose and the mouth. The rubella virus infects the lining of the
nose and the upper respiratory tract. Then, it is spread through the blood throughout
the body, which causes the rash.
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What are the common findings?
The symptoms of rubella are variable and usually very mild. Up to one-half of persons
have no symptoms at all. The typical symptoms of a rubella infection are a low-grade
fever, swollen lymph nodes ("lymphadenopathy"), and a rash. Such symptoms as fatigue
and poor appetite usually are not prominent.
Swollen lymph nodes of the neck are a common feature of rubella. Classically, it
appears one day before the rash, and is most prominent in the lymph nodes behind
the ears and in the back of the neck. After approximately 12 to 24 hours, the rash
appears. The rash is a flat rash that appears all over the body and is very subtle.
The rash usually disappears within two to three days. It is commonly itchy in adults,
but not in children.
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How is rubella diagnosed?
Rubella is diagnosed primarily on initial suspicion from the clinical and physical
examination findings and confirmation by a laboratory test for rubella antibodies.
The appearance of the rash usually is not characteristic. It is very difficult to
be certain of the diagnosis of rubella without testing for the antibodies (i.e.,
IgM antibodies) found early in the illness.
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How is rubella treated?
There is no specific treatment for rubella. Antibiotics are not helpful because
a virus causes rubella. Viruses cannot be treated with antibiotics. Fortunately,
most persons with rubella have either no symptoms or very mild symptoms, and have
complete recovery. The fever should be treated with acetaminophen or ibuprofen.
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What are the complications?
Complications of rubella are very uncommon in children. Young female adolescents
and young women are more likely to develop transient joint aches and pains that
typically affect the fingers, knees, wrists, elbows, and ankles. Usually, this lasts
for one to four weeks; however, some patients develop chronic arthritis.
Approximately 1 in 3,000 cases of rubella will develop very low platelet counts,
which can interfere with blood clotting. Inflammation of the brain ("acute encephalitis")
may occur in approximately 1 out of 5,000 to 24,000 cases.
Progressive rubella panencephalitis is a rare chronic encephalitis associated with
a persistent rubella virus infection of the brain. Approximately 20 cases have been
reported, all in males who were 8 to 21 years of age at the onset of the symptoms.
Most of these patients also had congenital rubella syndrome. No new cases have been
described in the United States in recent years due to the routine rubella vaccination.
A major complication of rubella is congenital rubella syndrome, which occurs when
a pregnant mother develops rubella and transmits the viral infection to the developing
fetus. The fetus may be severely affected with poor intrauterine growth, cataracts,
deafness, and heart defects. These and other findings are usually present at birth.
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How can rubella be prevented?
A vaccine for roseola is not available. There is very little information on how
to prevent Rubella is effectively prevented by the routine administration of the
rubella vaccine, usually given as Measles-Mumps-Rubella (MMR) vaccines to all children.
This vaccine is recommended beginning at 12 months of age. A single dose of the
rubella vaccine results in protection of approximately 95% of children. A second
dose of MMR is recommended at four to six years of age. It is not a problem if an
additional dose of the rubella vaccine is given in addition to the two recommended
doses.
The spread of rubella can be prevented by minimizing exposure to children who have
symptoms of the disease, and by good handwashing after exposure to the disease.
Pregnant women should routinely be tested in early pregnancy for antibodies to rubella.
If a pregnant woman who does not have antibodies is exposed to rubella in the first
trimester, antibodies can be given as soon as possible to try to prevent infection
of the fetus and congenital rubella syndrome. Pregnant women who do not have rubella
antibodies should be immunized immediately after delivery.
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What research is being done?
Because rubella is now extremely uncommon, and because the vaccine is extremely
safe and effective in preventing rubella, there is not much research on rubella
currently being performed. There is some research being conducted on the role of
the rubella virus in causing arthritis that some persons develop, and on the long-term
immunity of the rubella vaccine to confirm that it does provide lifelong immunity.
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About the Authors
Hal Jenson, M.D.
Dr. Jenson graduated from George Washington University School of Medicine in Washington,
DC,
He also completed a residency in pediatrics at the Rainbow Babies and Children's
Hospital of Case Western Reserve University in Cleveland, Ohio, and a fellowship
in pediatric infectious diseases and epidemiology at Yale University School of Medicine.
Dr. Jenson has an active research program on the biology of Epstein-Barr virus and
other human and non-human primate herpes viruses.
He is active in the general pediatric and infectious diseases teaching and clinical
activities of his Department and Division, is a co-editor of Nelson Textbook of
Pediatrics and of Pediatric Infectious Diseases: Principles and Practice, and authors
the book Pocket Guide to Vaccination and Prophylaxis.
Charles T. Leach, M.D.
Dr. Leach received his medical degree at the University of Utah School of Medicine
and completed his pediatrics residency as well as a fellowship in pediatric infectious
diseases at UCLA.
He is currently Associate Professor and Director of Research in the Department of
Pediatrics at the University of Texas Health Science Center at San Antonio.
Dr. Leach conducts scientific research in the areas of herpes virus infections,
pediatric AIDS, and infectious diseases among residents of the Texas-Mexico border.
Copyright 2012 Hal B. Jenson, M.D., and Charles T. Leach, M.D., All Rights Reserved
