Risk factors for perinatal transmission of HIV among women attending prevention of mother-to-child transmission clinics in Northwest Nigeria

Despite the effectiveness of antiretroviral therapy (ART) in the prevention of mother-to-child transmission of HIV (PMTCT), some HIV-infected women in PMTCT care are at risk of transmitting HIV to their babies. Using a 1:1 unmatched case-control study design, we assessed the risk factors for perinatal transmission among women who received ART for PMTCT in Sokoto State, Nigeria. Data were abstracted from medical records of cases (94 HIV-infected babies) and controls (94 HIV-uninfected babies) and their mothers who accessed PMTCT services in three purposefully selected secondary health facilities. We conducted univariate and multivariate logistic regressions to determine if sociodemographic characteristics, time of enrolment, type of maternal ART, receipt of infant antiretroviral (ARV) prophylaxis, place of delivery, or feeding practice were associated with HIV infection among HIV-exposed babies. Sixteen percent of the mothers of babies in the case group had early enrolment while 90% of those in the control group enrolled early. Infant prophylaxis was received in 54% of cases and 95% of controls. In both groups, 99% of the mothers practiced mixed feeding. In the univariate analysis, factors that were significantly associated with HIV infection were religion (islam), rural residence, late enrolment, and non-receipt of infant ARV prophylaxis. In the multivariate analysis, rural residence (Adjusted odds ratio (aOR) = 8.01, 95% CI = 1.79-35.78), late enrolment (aOR = 41.72, 95% CI = 15.16-114.79), and non-receipt of infant ARV prophylaxis (aOR = 4.1, 95% CI = 1.18-14.33) remained statistically significant. Findings from this study indicate that eliminating MTCT in Nigeria requires interventions that will enhance timely access of ART by mother-baby dyads.