Epidemiology of Cytomegalovirus among pregnant women in Africa

Introduction: Vertical transmission of Cytomegalovirus (CMV), resulting in congenital CMV (cCMV) infection could have disabling and potentially fatal effects on the foetus or neonate. Although primary infection probably has a higher risk of leading to cCMV, in highly seropositive populations, a significant risk of vertical transmission is thought to be due to CMV reactivation and or reinfection during pregnancy. In this narrative review, we summarise the prevalence of CMV infection and associated risk factors among pregnant African women, in a setting where primary CMV infection usually occurs during infancy. Methodology: A systematic search of literature published between January 2000 and January 2019, retrieved on five bibliographic databases was performed. Search for relevant articles was performed using the following keywords: cytomegalovirus, CMV, infection, antenatal infections, pregnancy, pregnant women, gravidity, developing countries and Africa, with appropriate qualifiers such as OR, AND. Results: Systematic searching retrieved 11 relevant original research papers. Prevalence of anti-CMV IgG and IgM antibodies ranged from 60-100% and 0-15.5%, respectively. Prevalence of CMV DNA ranged from 0-29%, depending on the specimen used. However, there was no geographic trend for CMV seroprevalence or CMV DNA prevalence across the African continent. Overall, a substantial percentage of women of reproductive-age were CMV seronegative and at risk of primary infection. Associations of sociodemographic factors with CMV infection were inconsistent across all reviewed studies. Conclusions: The limited data and inconsistency of findings from the few studies carried out in Africa calls for prospective studies comparing prevalence and outcomes of cCMV in infants born to women with both primary and reactivated CMV in Africa.