Seroepidemiology study of Cytomegalovirus and Rubella in pregnant women in Luanda, Angola: geospatial distribution and its association with socio-demographic and clinical-obstetric determinants.

Background: Both CMV and Rubella virus infections are associated with the risk of vertical transmission, fetal death or congenital malformations. In Angola, there are no reports of CMV and Rubella studies. Therefore, our objectives were to study the seroprevalence of anti-CMV and anti-Rubella antibodies in pregnant women of Luanda (Angola), identify the risk of primary infection during pregnancy and evaluate the socio-demographic risk factors associated with both infections.

Methods: A prospective cross-sectional study was conducted from August 2016 to May 2017. Specific anti-CMV and anti-Rubella antibodies were quantified by electrochemiluminescence and demographic and clinical data were collected using standardized questionnaire. Bivariate and multivariate logistic regression analysis were used to quantify the effect of clinical and obstetric risk factors on virus seroprevalence.

Results: We recruited 396 pregnant women aged from 15 to 47. Among them, 335 (84.6%) were immune to both CMV and Rubella virus infections, while 8 (2.0%) had active CMV infection and 4 (1.0%) active RV infection but none had an active dual infection. Five women (1.2%) were susceptible to only CMV infection, 43 (10.9%) to only RV infection, and 1 (0.3) to both infections. Multivariate analysis showed a significant association between Rubella virus infection and number of previous births and suffering spontaneous abortion.

Conclusions: Overall, this study showed that there is a high prevalence of anti-CMV and anti-Rubella antibodies in pregnant women in Luanda. It also showed that a small but important proportion of pregnant women, about 11%, are at risk of primary infection with rubella during pregnancy. This emphasizes the need for vaccination.