Effectiveness of nevirapine and zidovudine in a pilot program for the prevention of mother-to-child transmission of HIV-1 in Uganda

Abstract

Background: Single dose nevirapine and a short course of zidovudine (AZT) are now administered in most hospitals in Uganda to prevent mother-to-child transmission (MTCT) of HIV. The effectiveness of these antiretroviral (ARV) regimens has been shown in the clinical trials but has not been demonstrated outside the clinical trials setting in this country.

Objectives: The study evaluated the effectiveness of short course ARV regimens in a pilot program to prevent mother-to-child transmission of HIV and determined the risk factors for perinatal transmission.

Methods: Cross-sectional study design was used to compare perinatal transmission rates of HIV in two sets of mothers: ARV-treated mothers and ARV-untreated mothers.

Results: 109 treated and 90 naïve mother-infant pairs were recruited. HIV transmission rates were similar in the nevirapine (10/61) and AZT (8/48) groups (16.4% vs. 16.7%) respectively but higher in the naive group (43/90 48%, p= 0.0001). ARV therapy offers a protective effect against MTCT of HIV (Adjusted Odds Ratio 0.22 95%CI 0.09, 0.54) but mothers in Stage 1 and 2 of disease were more likely to benefit from this intervention than mothers in Stage 3 and 4.

Conclusion: In this community-based observational study, ARV reduces the risk of perinatal transmission of HIV but does not eliminate the risk completely. Early screening of asymptomatic pregnant women will identify a group of mothers more likely to benefit from the intervention.

Figure 1

Study Population, Screening and Recruitment Figure 1. Summary of the enrollment of mothers at the clinics. 1003 naïve mothers were screened and of these 129 or 13% were HIV-1 positive. 115 treated mothers were enrolled. 52 of these had received AZT while 63 had received nevirapine. Mothers excluded in the analysis either did not consent to have their child in the study or had HIV results for their infant missing.