Rubella Immune Status in Pregnant Women in Central Morocco

Rubella is a contagious viral infection that affects pregnant women during early pregnancy which leads to the infection of a developing fetus, causing congenital rubella syndrome (CRS). Although rare in many industrialized countries, because of the success of vaccination programs, rubella continued to occur in many developing countries with no vaccination program. Rubella immunization rates are not optimal; World Health Organization (WHO) recommends that countries without vaccination programs should assess the burden of rubella infection and CRS. In Morocco, Rubella containing vaccine (RCV) was introduced in routine immunization of children in 2003. In a retrospective cross-sectional study was conducted between January and December 2015, we sought to determine the sero-prevalence of anti-rubella IgG in 1399 pregnant women in our region. The mean age was 31.20 ± 5.90 years (range 17 45 years) using chemiluminescent microparticle immunoassay and we examined for anti-rubella IgM antibodies for sera considered negative (< 10 IU/mL) for rubella IgG. A questionnaire was used to obtain the socio-demographic and behavioral characteristics for 280 the pregnant women. A total of 1240 of the pregnant women examined were positive (≥ 10 IU/mL) for rubella IgG giving a prevalence of 88.6 %, and 159 (11.4%) were susceptible. There was no evidence of recent infection within the study period. Study period as shown by negative IgM result. The quantitative analysis for rubella IgG showed a noticeable variability in the values of antibodies that ranged between 0-263 IU/ml. A clear majority of the sample had values of antibodies >50 IU/ml. Although most women tested were seropositive for rubella IgG (81% 94.6 %) according to the socio-demographic and obstetrics characteristics, suggesting a natural virus circulation within the community, screening for protective immunity followed by vaccination to those who were susceptible should be enforced to prevent possible rubella congenital syndrome. Most (11.4%) of the pregnant women who were sero-negative in their first pregnancy were not immunized against rubella.