Contributed by – Healthians Team
What is Rubella test?
Rubella which is also known as German measles or three-day measles is not a major problem for most of us. It causes mild fever and rashes for a few days. Kids get vaccinated for it by MMR i.e. measles-mumps-rubella or MMRV which also includes chickenpox shots. During pregnancy, rubella should not be taken lightly. If you are infected with the rubella virus during pregnancy, then you can transmit the disease to the baby (fetus). And serious birth defects like eye problems, hearing impairment, and heart disease could develop, especially during the first trimester.
When your body gets infected with the rubella virus it defends itself by producing two types of antibodies in sequence. First, your body produces IgM which appears three to seven days after the onset of symptoms and stays for a few weeks. Then comes IgG which appears a few days after IgM and stays in your bloodstream for the rest of your life. IgG provides long-term immunity due to a prior infection and vaccination.
Who should get the test?
A woman who is pregnant or planning to have a baby needs rubella test to ensure that she is protected against rubella (risk of fetal malformation during the first trimester). Also, a newborn baby whose mother might have had rubella when she was pregnant needs this test. Your doctor will prescribe this test done if he suspects that you might have rubella. Your baby will also need these tests after birth.
If you have symptoms of the disease, then you should go for the test. Healthcare workers who were not vaccinated for the same should get the test done. College students should also go for the test.
Why is the test needed?
The rubella blood test is conducted to see if you have antibodies to the rubella virus. Antibodies are proteins made by your immune system to fight infections. They also prevent you from getting sick. They target specific germs, viruses and other microbial invaders. Your health care practitioner can tell you from the type of antibodies present in your blood.
What does the Rubella test results mean?
This is how your Rubella IgG test results appear:
- A positive test is 1.0 or higher. It means you have rubella antibodies in your bloodstream. You are immune to future infections.
- A negative test is 0.7 or lower. You have very less antibodies and they can’t be detected.
- A score of 0.8 or 0.9 could mean you just had vaccination. Antibodies haven’t shown up in your bloodstream yet. Your doctor might ask you to take the test again.
A positive IgM test means that you have IgM present in your bloodstream. It could be because you’ve recently been infected. Since rubella is not a very common illness, the test may be a false-positive. It means that you might be infected with a different virus and the test is responding to other proteins present in your bloodstream. You will need more tests to confirm the results. Babies can’t get IgM antibodies from their mothers; so if a newborn tests positive then they were infected before or just after birth.
How is the test done?
A technician uses a needle to take a small sample of blood from a vein in your arm. The blood sample is taken sent to a lab for testing. In general, there is no specific preparation required before this test, unless your doctor tells you to. There is very little chance of having any problem with this test.
