For waria, commercial sex locations were randomly selected from the sample frame, and all sex workers were approached at each location by trained field workers, including waria, who explained the study purposes and procedures.
The overall refusal rate was 26%, and 241 waria were included in analysis.
Blood was drawn for HIV and syphilis serology and community interviewers administered a standardised questionnaire.
Results: HIV prevalence was 22% among transgender sex workers, 3.6% among male sex workers, and 2.5% among self recognised MSM, and syphilis prevalence was 19.3%, 2.0% and 1.1% respectively.
For syphilis testing, sera were screened using a rapid reagin test (Macro View RPR, Becton Dickenson, Meylan, France).
Sample frames were drawn up of locations weighted for peak cruising times.
The questionnaire differed slightly for the three groups in accordance with group characteristics.
Immediately after collection, blood samples were transferred to a cooler, and processed daily at the National HIV Reference Laboratory in Jakarta.
The study was anonymous; biological specimens and questionnaires were linked by unique number, which participants could use to access test results.
Blood was drawn and trained interviewers administered a pretested, structured questionnaire with sections on demographics, sexual behaviour, HIV/AIDS knowledge, risk perception and testing history, STI knowledge and treatment seeking, exposure to HIV prevention interventions, alcohol and drug use.