The birth prevalence of congenital CMV infection in HIV-exposed newborns in Cape Town, South Africa : a pilot study. The "CYPREHEN" (Cytomegalovirus prevalence in HIV-exposed newborns) study.
Background Congenital cytomegalovirus infection (CMV) is a leading non-genetic cause of sensorineural hearing loss worldwide. The birth prevalence of congenital CMV infection correlates positively with the level of CMV seroimmunity in the adult population. In addition, women infected with Human Immunodeficiency Virus (HIV) constitute a special at risk subpopulation for the intrauterine transmission of CMV. Despite a high prevalence of both HIV and CMV, the birth prevalence of congenital CMV infection has not been assessed in sub-Saharan Africa. Purpose The purpose of the study was to determine the birth prevalence of congenital CMV infection among HIV-exposed newborns born in a public sector hospital in the Western Cape in 2012, during the era of prenatal antiretroviral therapy. Objectives The objectives of this study were: To determine the prevalence of congenital CMV infection among HIV-exposed newborns; To assess the predictors of congenital CMV infection transmission among HIV-infected women; and To inform the design of an analytic study to determine if newborn CMV screening should be implemented in this population. Study design An observational descriptive cross-sectional study design was used. Settings The study was conducted at Mowbray Maternity Hospital (MMH), which serves the Cape Town Metropole area. Study population The study population comprised infants born to HIV-infected mothers delivering at MMH. Study sample Non-probability convenience sampling was used to enroll 750 newborns. Methods HIV-infected mothers were recruited in the immediate postnatal period at a referral maternity hospital between April and October 2012. Maternal and infant clinical data and newborn oral swabs (saliva) were collected. Saliva was assayed by real-time PCR for CMV. Data were analysed using univariate and multivariate logistic regression analyses to determine specific demographic, maternal and newborn characteristics associated with congenital CMV infection. Results CMV was detected in 22/748 newborn oral swabs (2.9%; 95% Confidence Interval (CI), 1. 9%-4.4%). Maternal CD4 count less than 200 cells/μL during pregnancy was independently associated with congenital CMV infection (adjusted Odds Ratio (aOR) 2.9; 95% CI, 1.2-7.3). A negative correlation between CMV viral load in saliva and maternal CD4 count was observed (r = -0.495, n = 22, p = 0.019). Conclusions The birth prevalence of congenital CMV infection was high despite prenatal ARV prophylaxis, and was associated with advanced maternal immunosuppression.