 HIV counseling and testing, risk reduction counseling, provision of condoms and lubricants Same-day result HIV testing along with pre-test and post-test counseling, including risk reduction counseling, will be provided according to the standard practice at each study site at enrollment and every 6 months in HIV-negative participants. HIV-negative participants can also access non-occupational post-exposure prophylaxis service and symptomatic STD service if these are available at study sites. HIV-positive participants will also receive risk reduction counseling every 3 months. Condoms and lubricants will be provided free of charge. 