Feasibility of northern Thai factory workers as participants in HIV vaccine trials.

To determine the feasibility of establishing a cohort of HIV-1 seronegative factory workers for potential HIV vaccine trials, and other HIV preventive interventions, we enroled and followed 499 male and female industrial workers in Lamphun Province, northern Thailand. A baseline demographic and HIV seroprevalence survey was conducted by a mobile team at worker's housing units in Lamphun Province in 1994. Follow-up HIV and syphilis incidence rates were measured 6 months later. The study was voluntary, anonymous, and included HIV pre- and post-test counseling, HIV and syphilis serology, and a self-administered fact sheet. A total of 106 men and 393 women were recruited. The median age was 22 years, and the mean 23.4 years. Educational levels were moderate; 41.9% had some secondary school and 23.6% had completed secondary school. HIV prevalence was 2.4% overall but differed by sex; among men it was 7/106, 6.6%, among women 5/393, 1.3%, OR = 5.49 (95% CI = 1.52, 20.39). Low educational levels were associated with HIV infection, OR = 7.2 (95% CI = 2.2, 23.4). Syphilis prevalence was 3.8%. Follow-up at 6 months was successful for 420/499 subjects, 84.2%, and varied by sex: 73/106 men, 68.9%, returned while 347/393 women, 88.3%, did so, RR = 1.21 (95% CI = 1.07, 1.37). There were 5 incident HIV-1 infections, a rate of 2.1/100 person years. The HIV seroconversion rate differed by sex, but not significantly; it was 4.1/100 person years for men and 1.5/100 person years for women. This population is largely young, female, and at considerable HIV risk. If follow-up could be improved, factory workers in northern Thailand could be an appropriate population in which to mount HIV preventive efficacy studies, including vaccine trials.

Duke Scholars

Author Christopher Charles Beyrer Medicine, Infectious Diseases