Background Maternal viral load (VL) and immunological status are important risk factors for mother-to-child transmission of HIV. In line with WHO recommendations (Option B+), Tanzania introduced the initiation of life long antiretroviral therapy (ART) in pregnant women in 2013. We present the uptake of ART and its impact on mother-to-child transmission.

Methods Between July 2015 and June 2016 data were obtained from HIV-infected pregnant women participating in the ongoing BABY Study (ClinicalTrials.gov Identifier: NCT02545296), which evaluates point-of-care testing in HIV Early Infant Diagnosis (HEID). Women were enrolled at the time of delivery, and neonates were followed-up until 6 weeks post-partum. Maternal HIV-RNA was assessed at delivery; neonatal HIV diagnosis was performed using the Cepheid Xpert point-of-care test and confirmed by qualitative dry blood spot HIV-DNA (Roche COBAS TaqMan).

Results In total 415 HIV-infected pregnant women were enrolled (median age 29 years). Nearly all women had attended antenatal care (96.4%); in 245 (59%) HIV was first diagnosed during pregnancy, and in 63.8% ART was initiated within 1 week following diagnosis. At the time of delivery 368 (88.7%) women were on ART, HIV-RNA >1000 copies/mL were detected in 78 (18.9%) and a CD4 count <200 cells/µL in 63 (15.2%). The overall mother-to-child HIV transmission rate was 2.4% (10/415) and 7/10 neonates were HIV diagnosed at the time of birth correctly identified by point-of-care testing. HIV-RNA >1000 copies/ml irrespectively of ART and low CD4 count <200 cells/μL were associated with higher risk of neonatal HIV transmission.

Conclusions Despite the implementation of life-long ART in all pregnant women, reduction of HIV transmission from mother to child is still sub-optimal. High HIV-RNA as the main risk factor for HIV transmission irrespective of maternal ART points to the need for maternal VL screening during the antenatal period.