HIV risk behavioral surveillance in Bangkok, Thailand: sexual behavior trends among eight population groups.

OBJECTIVE: To assess trends in HIV risk behaviors over a 3-year period in eight population groups in Bangkok, Thailand. DESIGN AND
SUBJECTS: Using a repeated cross-sectional survey design with a structured questionnaire, we collected five sets of self-reported sexual behavior data related to HIV risk from the following subject groups at the same sampling sites during 1993-1996: direct and indirect female sex workers, male attenders of sexually transmitted disease (STD) clinics, female attenders of antenatal care clinics, male and female vocational students, and male and female factory workers.
RESULTS: Reported patronage of commercial sex by the three male groups declined by an overall average of 48% over the 3-year period. Other non-regular sexual partnerships declined among male STD clinic attenders and vocational students. Condom use during most recent sexual intercourse between sex workers and clients peaked at high levels (>90%) in the early data waves, while among indirect sex workers and their clients, consistent condom usage increased from 56% to 89%. Low condom use persisted among sex workers and their non-paying sex partners. Single women reported low levels of sexual activity and condom use with no signs of an increase. Similarly, married women from antenatal clinics reported low condom use with their husbands, with no change throughout the period of the study.
CONCLUSIONS: HIV risk behavioral surveillance is a useful way of determining whether behavior change has occurred in specific population groups. The results here confirm and add to a growing set of evidence of risk behavior reduction in Thailand. The behavioral changes did not occur uniformly but varied depending on the sexual dyad and the population group under study. Behavioral surveillance should be promoted and its methodologies strengthened in attempts to understand the local dynamics of HIV epidemics.