What is Rubella?
It is a contiguous viral infection which takes place mostly in children & young adults. It is the most leading vaccine-preventable cause of birth defects. The infection is characterized by fever & rash which lasts for two to three days. In pregnant women, rubella infection causes fetal (unborn offspring) deaths or congenital birth defects known as congenital rubella syndrome.
What is Rubella IgM Lab test?
It is a Rubella antibody test which detects presence of IgM antibodies in the bloodstream. It is the standard test for rapid laboratory diagnosis of rubella infection. Rubella antibodies are measured in the blood which is produced by the body's immune system in response to immunization or infection by the rubella virus. IgM antibodies are the first ones to appear when one gets infected with rubella. It indicates recent infection and sticks around for 7 to 10 days in adults while a year in newborns.
Why is Rubella IgM test done?
Rubella test is used to detect antibodies in blood in response to rubella infection or immunization. The test is ordered when a woman is pregnant or planning to become pregnant or shows signs & symptoms of rubella infection. In a newborn, it is ordered when the mother was diagnosed with rubella infection during pregnancy or the infant has birth defects which can be due to CRS (congenital rubella syndrome). It is required anywhere when checking for immunity against rubella is needed.
- What is the relation between rubella & fertility?
Rubella infection is said to be very dangerous for unborn babies, therefore, women of childbearing age are advised to undergo rubella immunity testing before conceiving.
- Is it important to get a rubella vaccine before conceiving?
It is recommended to get an MMR (measles, mumps, rubella) vaccine at least a month before getting pregnant to protect against rubella infection during pregnancy.
- What is the meaning of Rubella IgM positive?
It means current or recent infection with Rubella virus.
- How dangerous is Rubella?
It is said to cause skin rash & joint pain. It can be mild in people but shows most terrible consequences of severe & permanent birth defects or death in unborn baby.
- What can be the best way to prevent rubella?
It can be prevented best by vaccination. Its combination vaccine protecting against measles & mumps is known to be MMR (measle, mumps & rubella) vaccine.
INTERPRETATION OF THE RESULTS:
The rubella IgM test is only done when your doctor suspects you are having a current/recent rubella infection. Results like:
- “Positive” with 1.1 AI or greater: you have had recent rubella infection or currently have one.
- “Negative” with 0.8 AI or less: No significant level of rubella IgM antibody is present to provide immunity against infection/patient doesn’t have a recent infection.
- “Equivocal” with 0.9-1.0 AI: repeat test after 10-14 days
- The IgM test can be false-positive i.e. you might be infected with different virus.
- IgM test showing “negative” can also be wrong if a person’s immune system is weak & despite being infected, they are not able to make enough antibodies to show in test.
- IgM antibodies are not passed from mother to the babies, so if newborn shows positive IgM result that means they’ve been infected before or just after the birth.