Cost-effective use of nevirapine to prevent vertical HIV transmission in sub-Saharan Africa

Objective: To assess the cost-effectiveness of alternative strategies of ne virapine (NVP) administration to prevent vertical HIV transmission in sub-S aharan Africa. Design: A decision-analysis model was constructed to estimate the costs and effects of NVP-based prevention strategies for two separate groups of wome n: those who qualify for standard therapy by attending a 36-week prenatal v isit, and those who do not qualify, owing to preterm delivery or lack of pr enatal care. Results: For women in prenatal care, mass provision of NVP without maternal serodiagnosis was found to yield greater health gains at an acceptable cos t, compared with providing targeted therapy to only those women identified as seropositive. However, this conclusion was strongly contingent on severa l uncertain assumptions, most importantly the probability that a woman who does not know her serostatus will nonetheless adhere to therapy. Among thos e women who present for delivery without prior enrollment in a prenatal str ategy, either late provision of maternal-infant NVP or treatment of only th e infant would likely be a cost-effective alternative to the current practi ce of offering no preventive therapy. Conclusions: NVP intervention offers a cost-effective avenue for preventing vertical HIV transmission in sub-Saharan Africa. The optimal choice betwee n mass therapy and targeted therapy cannot be confidently identified withou t information regarding adherence among women who do not know their serosta tus. For women who do not receive NVP prenatally, treatment on presentation for delivery would be cost-effective even in the face of modest clinical e fficacy. Clinical assessment of adherence to therapy among women who do not know their status and the field effectiveness of alternative approaches to NVP administration is urgently needed to allow identification of optimal p revention strategies.