Reduction of HIV transmission rates from mother to child in the era of antiretroviral therapy in the Lake Victoria zone, Tanzania

Background: Since the introduction of prevention of mother to child transmission (PMTCT) in Tanzania, HIV infection rates have been reduced in different regions across the country. However, there is limited published data from the Lake Victoria zone of Tanzania regarding the effectiveness of various regimens used for PMTCT. This study was done to assess the effectiveness of antiretroviral therapy in preventing mother to child transmission of HIV Methods: Infants aged ≤18 months born to HIV positive mothers undertaking PMTCT programme and those with no intervention program from Mara, Kagera, Mwanza and Shinyanga were tested for HIV-1 DNA polymerase chain reaction (PCR). Data were analysed using STATA version 10.0 to assess factors associated with outcome. Results: A total of 1,005 study subjects were enrolled in the study. Of these 55% (554/1005) were females. Majority (82.6%; 830/1005) of the infants studied were aged 1-6 months. The median age of the infant studied was 3 months (IQR 2-4). Out of 1005 non-repetitive samples; 61(6.1%) were HIV-1 DNA PCR positive. Positive dried blood spots (DBS) rates by region were 6.4%, 5.9%, 5.6% and 5.1% in Mwanza, Mara, Kagera and Shinyanga, respectively. During pregnancy interventions, the positive rate for women with no therapy was 12.6% and for zidovudine alone was 5.4% while for triple antiretroviral therapy was 0.5%. Women who were in highly active antiretroviral therapy (HAART) during pregnancy had significantly lower positive rate than those without HAART treatment (p=0.001). Of 755 infants who received nevirapine, 3.9% were DBS positive compared to 12.8% of those who didn't receive nevirapine (p=0.001). Conclusion: The use of antiretroviral therapy in the PMTCT programme is effective in reducing HIV transmission from mother to child.