The Biomarker Handbook is a curated series that seeks to provide readers with insights on each biomarker we cover in our blood test packages and its relation to our body.
Before 1969 (and routine vaccinations), there were rubella infection outbreaks that lasted several years. According to the CDC there were 12.5 million cases of rubella in the U.S. alone from 1962-1965, during which 20,000 infants were born with CRS (congenital rubella syndrome). Today, we have just about eradicated this disease in places where vaccination coverage is highest (the Americas). African and southeast Asian countries have lower vaccination coverage, but efforts are made (headed by WHO) to eradicate measles, mumps and rubella by 2020.
What is Rubella and How Does it Present Itself?
Rubella sometimes referred to as German measles, is an acute infectious disease caused by the rubella virus. Globally 100,000 babies are borne annually with the congenital rubella syndrome (highly debilitating and even deadly disease with severe birth defects caused by rubella infection).
This disease most often presents only with mild symptoms for a short duration. The symptoms include low-grade fever and malaise in the first few days, followed by the emergence of a rash and swelling of your glands behind the ear. The rash typically appears first on the face and progresses in the downward direction; it is lighter in colour than the rash seen in measles.
In rare instances, the disease can cause certain complications including conjunctivitis (eye infection), painful and inflamed joints and much less commonly encephalitis (brain infection) and thrombocytopenic purpura (excessive bruising and bleeding).
Rubella virus is highly contagious via respiratory droplets and from mother to unborn child. A person can be highly contagious one week before the appearance of the rash and a week after it faded.
Why is Rubella Such a Feared Disease?
Although the clinical findings of rubella in adults are mild and usually not a cause of worry, if a pregnant woman is infected, this disease can cause dire consequences on the unborn child.
If a pregnant mother is infected in the first trimester, especially in the first month, there is a high risk for miscarriage, preterm delivery, even stillbirth or infection of the fetus which causes congenital abnormalities involving the eyes (cataracts), brain (deafness, mental retardation) and heart (congenital heart defect). This triad of organ involvement is collectively referred to as the congenital rubella syndrome or CRS. There is an 85-90% probability of infecting the baby if a pregnant mother is infected with rubella in first trimester.
Rubella virus in newborns with CRS can also be a cause of concern for the community around. The virus causes a chronic condition in a child with CRS unlike the acute disease in adult. The virus is excreted for months by the newborn and this can spread to the population around.
Detecting Immunity: Rubella IgG Antibody Test
The biomarker called rubella IgG antibody test determines if you have sufficient rubella antibodies to protect you from the rubella virus, either from a past infection or vaccination. If the test is positive, then you are immune to the infection.
Even people who have been vaccinated may test negative to the IgG test (not a lifelong vaccine, or do not develop antibody to the vaccine). So every woman who is pregnant should take this test to see if they are protected.
This test is extremely helpful for those who are planning to get pregnant as well. Women who test positive for the IgG rubella antibody are protected and need not worry about CRS. However, if tested negative, it means that you are not immune and at risk of developing the infection if in contact with someone infected. Women who are planning for pregnancy and negative for IgG should see their clinician for rubella vaccination before getting pregnant. They must not get pregnant within 1 month of receiving the vaccine. Women who are pregnant and not immune to rubella should NOT receive the vaccine. You must, however, take measures to protect yourself and the unborn child from rubella. This means staying away from people with rubella or suspected rubella, abstain from travelling to endemic regions, and also get everyone in your family tested and vaccinated.
If you develop symptoms suggestive of rubella infection, your doctor may also order the IgM rubella antibody test, which detects a recent infection rather than immunity. If positive, then this confirms that you have an infection or recently recovered from it.
Prevention of Rubella Through Vaccination
Vaccination against rubella is the main form of prevention against the disease. Before vaccinating, it is important to get yourself screened. This will reveal whether you are already immune or not. A positive test denotes the presence of IgG antibodies in the blood. A negative score, on the other hand, shows that you are NOT immune and can be at a risk of infection.
For sexually active women, it is recommended that you ensure you are not pregnant before receiving the rubella vaccine. Rubella vaccination should NOT be given to pregnant women. Once you have been vaccinated, you should wait for a month before trying to get pregnant.
Vaccine Schedule: The rubella vaccine is administered as an injection. This vaccine can provide long time immunity (for up to 14 to 16 years). It is also a part of the EPI (expanded program immunization) schedule in infants and is given in combination with the vaccine of mumps and measles (MMR) at the age of 12-15 months. Children under 1 year are not vaccinated since they still carry maternal antibodies and the vaccine is shown to be less effective before one year of age.
Screening for Rubella Immunity in Pregnant Women
Since the virus can cause untoward consequences in the child in utero, all pregnant women are advised to get screened. In fact, some hospitals make it a requirement to demonstrate immunity against rubella in all expecting women.
This is an important step to prevent congenital defects (congenital rubella syndrome).
Who is at Risk of Rubella?
Any unimmunized individual is at risk of rubella. Although the disease was declared to be eliminated in certain countries, travellers going out of the country to where rubella is not completely eradicated are at a high risk of getting infected.
Pregnant women and those individuals who have lowered immunity can also contract the viral disease more commonly.
Can Rubella Be Eradicated From the World?
With the emergence of potent vaccines and the spread of awareness, rubella is now much more controlled than it was a few decades ago. With strict measures to limit the virus’s transmission and regular screening of pregnant mothers, there is hope that this disease, like smallpox, can one day be eradicated worldwide. In the meantime, let’s all do our parts to protect those unborn babies from this horrible illness.
If you want to find out more about rubella and testing during pregnancy, take a look at our lifestyle article here!
Interested in other biomarkers? Check out the rest of The Biomarker Handbook.
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