To measure HIV prevalence and associated risk factors among female sex workers, injecting drug users (IDUs) and men who have sex with men (MSM) in Lebanon and the prevalence of hepatitis B virus and hepatitis C virus among IDUs. A cross-sectional survey of 135 female sex workers, 81 IDUs and 101 MSM was recruited using respondent-driven sampling. A structured interview was conducted by members of nongovernmental organizations working with these populations and blood was collected for serological testing. HIV prevalence was 3.7% among MSM but no HIV cases were detected among female sex workers or IDUs. Among IDUs, prevalence of hepatitis C virus antibody was 51% and prevalence of hepatitis B virus surface antigen was 5%. Three-quarters of MSM had nonregular male sexual partners during the last year but only 39% reported using a condom every time. There was evidence of overlapping HIV risk: 36% of MSM and 12% of IDUs reported that they had sold sex. Previous testing for HIV was lowest among MSM (at 22%) despite their having the highest level both of knowledge about HIV and of perception of being at risk of HIV infection (67%). Prevention efforts at greater scale are needed to reach these at-risk populations in Lebanon. These should target MSM in particular, including access to HIV testing, but will need to address and overcome stigma. For IDUs, surveillance and prevention efforts should integrate both hepatitis C virus and HIV.
