Infections averted by a comprehensive HIV prevention intervention and its cost-effectiveness: a prospective cohort study of persons who inject drugs in Delhi, India

This paper presents the cost-effectiveness of a WHO-recommended harm-reduction programme implemented among a cohort of persons who inject drugs in Delhi, India. We estimate the number of infections averted using Bernoulli process model and calculate cost-effectiveness ratio as the total programme cost per infection averted. The intervention averted 996 HIV infections over 36 months, with a cost-effectiveness ratio of INR 24,763 (US$ 476) per infection averted per year. The first phase, when HIV testing and counselling were initiated, was more cost-effective than the second phase when full intervention package, including needle-syringe exchange, condom distribution, harm-reduction education, etc., was implemented.