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.

This study is a prospective observational cohort study that will enroll up to 6,000 Thai MSM and TG from drop-in centers in Bangkok, Chiang Mai, Chonburi and Songkhla. Each participant will have HIV testing at baseline and will be followed up for 18 months.

HIV-negative participants will be asked to have HIV re-testing every 6 months. HIV-positive participants will have POC CD4 testing and ART initiation regardless of CD4 count will be offered. Those who accept ART will be followed up at week 2, week 4, month 2, month 3 and every 3 months thereafter. Those who deny ART will be followed up every 3 months.

Uptake of HIV re-testing will be determined. Access to POC CD4 testing and acceptability of ART initiated at HIV diagnosis regardless of CD4 count along with ART adherence will also be determined.

Inclusion Criteria:

1. Thai national
2. Age >18 years
3. Men or transgender women who report unprotected anal intercourse with a man at least one time in the past 6 months
4. Not known to be HIV-positive, i.e., never tested for HIV or previous HIV test(s) negative
5. Willing to participate in the study
6. Provide written informed consent

Exclusion Criteria:

1. Known HIV-positive serostatus

1. SWING Drop-In Center, Bangkok, Thailand
2. RSAT Drop-In Center, Bangkok, Thailand
3. Chiang Mai Buddy Station, Northern Thailand
4. SWING Drop-In Center, Pattaya, Chonburi, Eastern Thailand
5. Sisters Drop-In Center, Pattaya, Chonburi, Eastern Thailand
6. RSAT Drop-In Center, Songkhla, Southern Thailand