Rubella Red Dog am I immune to it?
This examination tests for:
- Rubella virus al. (HHT) from serum
- Rubella IgG from serum
In the case of detection of rubella virus antibodies in the HHT test (inhibition of hemagglutination), immunity can be assumed if the titer is sufficient. Doubtful findings and low antibody titers should be confirmed by further investigation.
Pregnant women are routinely tested for rubella. This is not necessary. If a pregnant person is seronegative and has ever been vaccinated (at least once), she is still protected. If she has never been vaccinated, vaccination can be offered after pregnancy.
What is rubella?
Rubella or rubella is a contagious spot disease caused by a virus. The disease usually has a mild course. When unprotected women experience rubella in the first half of pregnancy, there is a risk of congenital abnormalities in the baby. A primary rubella infection in the first 4 weeks of pregnancy gives a high risk of congenital rubella syndrome (CRS) (± 80%). This can manifest as deafness, cataracts, cardiac abnormalities, pulmonary hypoplasia, and central nervous system disorders, among others. The risk of clinical abnormalities decreases as the pregnancy progresses (at 13-16 weeks of pregnancy ± 10%). In the second half of pregnancy, the incidence of rubella associated abnormalities is less than 2%.
From 1974, vaccination against rubella was included in the National Vaccination Programme (RVP): first only for girls, and from 1987 as part of the BMR vaccination for all children. Because most children are vaccinated, the disease is not very common in the Netherlands anymore.
What is the rubella screening policy during pregnancy?
There is no national, uniform screening policy for rubella. The Dutch Society of General Practitioners recommends that the rubella titre only be determined for women who are unlikely or uncertain to have been vaccinated in the past, such as foreign women. Pregnant women who have been vaccinated against rubella should be considered sufficiently protected. For those women, rubella screening in pregnancy is not necessary.
Evaluating the result of a screening test.
A rubella test result with an IgG value of 20 IU/ml or higher is considered sufficient protection. For lower values, the interpretation depends on what the laboratory indicates.
If the vaccination was given a long time ago and there has been no boosting through natural exposure, the antibody titer drops. Thus, the height of the measured titer actually says little about the immunological memory present. When a screening has been performed on a routine basis and turns out to be negative, the policy is still to check whether the woman has ever been vaccinated. If so, she may be considered protected.
Seroconversion occurs after vaccination in 98-100% of vaccinated persons. The protective effect of vaccination is 95-97%. The protection lasts for a long time due to a memory effect. If the woman has not been vaccinated before, there is an indication for mumps/mumps/ rubella (BMR) vaccination if she wants to become pregnant again in the future. After the pregnancy ends, vaccination can still be done. Pregnant women who have had contact with someone with rubella and it is not clear whether they have been vaccinated against rubella should contact their midwife, gynecologist, or family doctor.
Source: The National Coordination of Infectious Disease Control (LCI) of the RIVM T. Oomen, Centre for Infectious Disease Control, RIVM, Bilthoven