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The Test Sample
What is being tested?
Rubella is a virus that causes an infection that is usually mild and characterized by fever and rash that last about 2 to 3 days. The Infection is highly contagious but is preventable with a vaccine. A rubella test detects and measures rubella antibodies in the blood that are produced by the body's immune system in response to immunization or an infection by the rubella virus.
Clinical diagnosis of rubella is unreliable; therefore, cases must be laboratory-confirmed. Antibody tests are the most common methods of confirming the diagnosis of rubella.
The rubella virus generally causes a mild infection marked by a fine red rash that appears on the face and neck and then travels to the trunk and limbs before disappearing a few days later. The virus is spread by contact with an infected person through coughing and sneezing. The infection can cause symptoms such as fever, enlarged lymph nodes, runny nose, red eyes, and joint pain. Symptoms may be so minimal, especially in children, that they go unnoticed and people do not know that they have a viral illness. In most people, rubella goes away within a couple of days without any special medical treatment and usually causes no further health issues.
The primary concern with rubella infection is when a pregnant woman contracts it for the first time during the first three months of her pregnancy. The developing baby (fetus) is most vulnerable to the virus at this time. If rubella is passed from a mother to her unborn baby, it can cause miscarriage, stillbirth, or congenital rubella syndrome (CRS), a group of serious birth defects that will permanently affect the child. CRS can cause intellectual and development disabilities, deafness, cloudiness of the lens of the eyes (cataracts), an abnormally small head, liver problems, and heart defects.
Because of the severe consequences for unborn babies, a national campaign was started in 1969 to immunize all children in the United States and to work to eradicate rubella infection, first in the U.S. and then throughout the world. The rubella vaccine is contained in a combination vaccine called MMR, which stands for measles, mumps and rubella. All children should receive two doses of MMR, the first dose at 12-15 months of age and the second dose at 4-6 years of age.
Prior to 1969 and routine vaccinations, rubella infections would emerge as cyclic outbreaks that lasted for several years. According to the Centers for Disease Control and Prevention (CDC), during the 1962-1965 rubella epidemic, 12.5 million cases of rubella occurred in the U.S. and there were 20,000 infants born with CRS. Due to vaccination efforts, these numbers have decreased drastically. The number of reported cases of rubella in the United States has declined dramatically to a median of 11 cases annually in 2005-2011.
The CDC now declares endemic rubella to be eradicated in the U.S., although people traveling from other countries bring it to the U.S. and the incidence continues to be monitored. People should not become complacent with this reduction, however, and the CDC cautions people to continue to have their children vaccinated. Anyone who has not received the vaccination as a child (and a few that have) may still be vulnerable to rubella infection.
Pregnant women and women considering pregnancy continue to be routinely tested for rubella antibodies to ensure that they are immune.
How is the sample collected for testing?
A blood sample is drawn from a vein in the arm of an adult or from a heelprick or the umbilical cord of a newborn.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.