Rubella Seroprevalence and real-time PCR detection of RUBV among Congolese pregnant women

BACKGROUND Rubella is an acute infectious disease caused by Rubella virus (RUBV). RUBV remains an important pathogen worldwide, causing approximately 100 000 cases of congenital rubella syndrome (CRS) every year; and the most severe consequence of rubella is teratogenicity. The aim of this study was to estimate the prevalence of RUBV IgG antibodies and determine RUBV genotypes in Congolese pregnant women in Kongo central province, Democratic Republic of Congo (DRC). METHODS This was a prospective cross-sectional study that consisted of a laboratory analysis of blood samples from 78 pregnant women to check for the presence of RUBV IgG antibodies, and also determine RUBV genotypes in seropositive samples (using primers targeting RUBV nucleoprotein), with the use of serological and molecular methods, respectively. Participants were pregnant women attending antenatal care clinics (ANC) at two health zones of Kisantu town in DRC. They were followed-up from the first to third trimester. Those who were negative for RUBV antibodies at the initial assay (first trimester) were tested in the second and, eventually, the third trimester. RESULTS An overall rubella seroprevalence of 58.97% was observed, whereas RUBV nucleoprotein was detected in 60% of randomly selected 30 blood samples among the 46 RUBV seropositive pregnant women. Five (27.77%) of positive samples were positive for both RUBV genotypes (RV8633/9112 and RV8945/9577), whereas 11 (61.11%) of them were positive for RV8633/9112 and two (11.11%) were positive for RV8945/9577 only. Regarding rubella clinical signs and complications, two subjects (2.56%) presented with fever, whereas five pregnant women (6.41%) had experienced abortion. None (0%) of the participants has been vaccinated against RUBV. CONCLUSIONS Findings from this study suggest that RUBV is prevalent in Congolese pregnant women. Further research is required to elucidate the molecular epidemiology of RUBV in order to design a rational rubella surveillance and control program in DRC.