Epidemiological Evaluation of Rubella Virus Infection among Pregnant Women in Ibadan, Nigeria

Rubella virus IgM and IgG antibodies with avidity in pregnant women and outcomes at a tertiary facility in Ghana

BACKGROUND

Congenital rubella syndrome (CRS) is a recognised cause of childhood deafness and blindness caused by the transplacental transmission of rubella virus during pregnancy. Women in the reproductive age group, and by extension their unborn babies may therefore be at increased risk. The prevalence of Rubella virus specific IgM and IgG antibodies, including IgG avidity, was determined in pregnant women attending the antenatal clinic at a Teaching Hospital in Ghana.

METHODS

One hundred and forty-five women in their second and third trimesters of pregnancy from the outpatient clinic were recruited over a period of 2 months after written informed consent was obtained. Study participants completed a questionnaire and venous blood drawn for IgM, IgG, and avidity testing using SERION ELISA (SERION® Immunologics, Würzburg, Germany). Babies of mothers with positive or indeterminate IgM and low avidity IgG antibodies were offered specialist cardiological, ophthalmological or hearing assessment during follow up.

RESULTS

One hundred and twenty-eight (88.3%) had only IgG antibodies, 5 (3.4%) had IgM and IgG antibodies, while 12 (8.3%) had no antibodies. No patient had IgM antibodies alone. Ten women (6.9%) had indeterminate levels of IgM antibodies. Majority of the women had high avidity IgG antibodies, while 5 (3.4%) had low avidity antibodies. No patient had IgM with low avidity antibodies. There was no statistical association between socio-demographic factors and the presence of IgM, IgG (low or high avidity) antibodies. Of all the children followed, none had the clinical definition of CRS.

CONCLUSIONS

Consistent with the World Health Organization elimination strategy for measles and rubella viruses, non-immune women in the reproductive age group should be vaccinated. The immunization programme should be expanded to include teenagers and adults. Though Congenital Rubella Syndrome was not detected, the risk still remains.

Sero-prevalence of rubella among pregnant women in Sub-Saharan Africa: a meta-analysis

Background: Rubella continues to be a leading cause of vaccine-preventable congenital birth defects and permanent organ damage, especially in developing countries. For women who are infected with the rubella virus (RV) before conception or during the first trimester of pregnancy, the unborn child has up to a 90% probability of developing congenital rubella syndrome. There are limited data on the seroprevalence of the rubella virus among pregnant women in Sub-Saharan Africa. Therefore, the aim of this study was done to determine the pooled seroprevalence of rubella among pregnant women in Sub-Saharan Africa. Methods: The PRISMA guidelines protocol was followed to write the systematic review and meta-analysis. Published studies were searched in Medline, PubMed, Google scholar, advance google and Cochrane Library. The search terms on the databases are: "rubella"OR "rubeo*", "rubella"AND"seroepidemiology", "seroprevalen *" OR "prevalen*", "seroprevalen *" OR "seroimmun*", "rubella antibod*"AND "pregnan*", "seroprevalen *" AND "sub-Saharan Africa".The heterogeneity of studies was weighed using Cochran's Q test and I² test statistics. Publication bias was assessed by using Egger's and Begg's test. Results: Twenty-eight studies were included in this meta-analysis. The pooled seroprevalence of anti-RV IgG among pregnant women in Sub-Saharan African was 89.0% (95%CI: 84.6-92.3), and the pooled prevalence of anti-RV IgM among pregnant women in Sub-Saharan Africa was 5.1% (95%CI: 2.6-9.9). Conclusion: This meta-analysis showed that seronegativity and acute infection with RV among pregnant women in sub-Saharan Africa is high compared to other studies and the WHO threshold among women of child-bearing age. This finding calls for primary health care providers to make the community aware of this rubella-susceptible group and its healthcare burden, with the desired outcome that sub-Saharan Africa countries would introduce an implementation strategy for rubella vaccination of pregnant women and women of child-bearing age.

Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon

Rubella infection in early pregnancy can lead to miscarriages, fetal death, or birth of an infant with congenital rubella syndrome (CRS). In Cameroon, like in many developing countries, rubella surveillance is not well-established. The aim of this study was to determine the prevalence of rubella virus specific antibodies among pregnant Cameroonians. We conducted a cross-sectional study for rubella infection among pregnant women attending antenatal clinics in the Center and South-West regions of Cameroon. Demographic data and blood were collected and tested for rubella specific antibodies (IgG and IgM), and for the IgM positive cases, IgG avidity and real time PCR was done. From December 2015 to July 2017, 522 serum samples were collected and tested from pregnant women. The seroprevalence of rubella specific IgG was 94.4%, presumably due to immunity induced by wild-type rubella virus. The seroprevalence of rubella specific IgM was 5.0%, possibly indicating rubella infection. However, IgG avidity testing of the IgM positive cases detected high avidity IgGs, ranging from 52.37% to 87.70%, indicating past rubella infection. 5.6% (29/522) of the participants had negative results for IgG to rubella virus, indicating susceptibility to rubella infection. None of the participants had received a rubella containing vaccine (RCV), but 51% (266/522) of the pregnant women lived in a house with a child with records of at least one dose of RCV. Rubella virus RNA was not detected in the urine of any IgM positive case. Findings from this study show that rubella infection is significant in Cameroon. Some pregnant women are still susceptible to rubella infection. For a better management of rubella infection in pregnancy in Cameroon, consideration should be taken to investigate for IgG-avidity test in cases with positive rubella IgM result to distinguish between recent from past rubella infection.