Progress in the Prevention of Mother to Child Transmission of HIV in Three Regions of Tanzania: A Retrospective Analysis

Background: Mother to child transmission (MTCT) of HIV-1 remains an important problem in sub-Saharan Africa where most new pediatric HIV-1 infections occur. Early infant diagnosis of HIV-1 using dried blood spot (DBS) PCR among exposed infants provides an opportunity to assess current MTCT rates. Methods: We conducted a retrospective data analysis on mother-infant pairs from all PMTCT programs in three regions of northern Tanzania to determine MTCT rates from 2008–2010. Records of 3,016 mother-infant pairs were assessed to determine early transmission among HIV-exposed infants in the first 75 days of life. Results: Of 2,266 evaluable infants in our cohort, 143 had a positive DBS PCR result at #75 days of life, for an overall transmission rate of 6.3%. Transmission decreased substantially over the period of study as more effective regimens became available. Transmission rates were tightly correlated to maternal regimen: 14.9 % (9.5, 20.3) of infants became infected when women received no therapy; 8.8 % (6.9, 10.7) and 3.6 % (2.4, 4.8) became infected when women received single-dose nevirapine (sdNVP) or combination prophylaxis, respectively; the lowest MTCT rates occurred when women were on HAART, with 2.1 % transmission (0.3, 3.9). Treatment regimens changed dramatically over the study period, with an increase i