Performance of PMTCT Among HIV Exposed Infants in Tanzania

Background: In Tanzania, 70% of the estimated 84,000 HIV-infected pregnant women who deliver annually receive some intervention to prevent mother to child transmission (PMTCT) of HIV. Few data exist concerning the effectiveness of various treatment approaches in a field setting across a large geographic area. Dried blood spot (DBS) HIV DNA PCR testing of HIV-exposed infants was first rolled out in Tanzania in 2008. Using data gathered for DBS testing, we evaluated the prevalence of perinatal HIV transmission based on PMTCT regimen across three regions of Tanzania.

Methods: This was a retrospective review of all mother/infant pairs enrolled in the National PMTCT program in the Kilimanjaro, Arusha, and Tanga Regions of Tanzania from January 1, 2008 to September 30, 2010. Enrollment registries at health facilities that submit DBS PCR were reviewed to document infant date of birth, weight, feeding practice, maternal and infant PMTCT regimen, and date and result of first DBS PCR. The present analysis included mother/infant pairs for whom DBS PCR was performed at infant age < 75 days. Maternal ARV regimens included: 1) none; 2) single-dose nevirapine (sdNVP); 3) sdNVP + zidovudine (combination prophylaxis); or 4) highly active antiretroviral therapy (HAART).

Results: In this field setting PMTCT is working better than hypothesized based on clinical trial results. Overall seroprevalence was 6.4% HIV transmission in the first 75 days of life. Women on HAART had the lowest transmission (2.1%), followed by those receiving combination prophylaxis (3.9%), sdNVP (8.9%), and no treatment having the highest rates (15.8%).

Conclusion: PMTCT regimens in resource-limited settings are effective and transmission rates are less than demonstrated by clinical trials data. Use of DBS for diagnosis of HIV provides an opportunity to evaluate use and effectiveness of PMTCT regimens.