Lifetime correlates associated with amphetamine use among northern Thai men attending STD and HIV anonymous test sites.

AIMS: To investigate the demographic, sexual, and other substance use risk correlates of amphetamine use among men in northern Thailand prior to the current epidemic of amphetamine use in the Kingdom. DESIGN: Cross-sectional quantitative behavioral questionnaires. SETTING: Thai Ministry of Health STD and HIV Anonymous Test Sites in the upper northern provinces of Chiang Mai and Lamphun. PARTICIPANTS: Adult Thai men recruited at clinics for enrollment in an HIV seroincidence cohort study (The Thai HIVNET). All men were HIV negative at enrollment, and had at least one self-reported sexual risk for HIV infection (a recent STD, use of sex workers, multiple sexual partners, low or absent condom use, sex with men). MEASUREMENTS: Participants answered a structured questionnaire. FINDINGS: Lifetime history of amphetamine use was reported by 133/914 men, 14.5%. Older age was protective for use (odds ratio (OR) 0.5) and use was associated with use of other substances; heroin (OR 7.1), thinner (OR 6.2), opium (OR 5.9), and marijuana (OR 5.7). Several STDs were associated with amphetamine use: gonorrhea (OR 2.3) and genital warts (OR 2.4), and any STD (OR 1.9). In multivariate analysis, use of heroin (OR 3.1), soft drugs (OR 4.9), and a history of gonorrhea (OR 2.0) were independently associated with amphetamine use in northern Thai men. CONCLUSIONS: Associations between young age, gonorrhea, other substance use and amphetamines indicate that prevention measures could occur at STD clinics and be incorporated into school programs when individuals are entering adolescence.

The molecular epidemiology of HIV-1 among male sex workers in northern Thailand.

Male commercial sex workers (CSWs) in northern Thailand are at high risk for HIV-1 infection and may be exposed to multiple subtypes of HIV-1 through sexual contact with men and women from Thailand, other Asian nations, and the West. We studied 103 male Thai nationals working in gay bars and clubs in Chiang Mai city who participated in the 1994 sentinel surveillance of the Thai Ministry of Public Health using HIV serologic testing, DNA polymerase chain reaction methods, molecular cloning, differential colony hybridization, nucleotide sequencing, and a third hypervariable region (V3) peptide enzyme-linked immunoabsorbent assay to differentiate subjects infected with HIV-1 subtypes B, E, both, or neither. The majority (58%) reported heterosexual orientation, and 35 (34%) were married. Seventeen (16.5%) were HIV infected: 16 (94%) of 17 had HIV-1 subtype E; 1 had HIV-1 subtype B. Two subjects had dually reactive results by molecular techniques but colony hybridization sequencing revealed only HIV-1 subtype E. HIV-1 subtype E appears to be the predominant clade among male CSWs in northern Thailand. This may have important implications for the global kinetics of the HIV epidemic.

PIP: Male prostitutes in northern Thailand are at high risk for HIV-1 infection and may be exposed to multiple subtypes of HIV-1 through sexual contact with men and women from Thailand and elsewhere. Blood samples of 103 male Thai nationals working in gay bars and clubs in Chiang Mai collected during the Thai Ministry of Public Health's 1994 sentinel surveillance were studied to determine the prevalences of HIV-1 subtypes B and E in the population. The men reported having an average of 2.5 male clients per week and had been in the business from 1 month to 7 years, with a median duration of 4 months. HIV serologic testing, DNA polymerase chain reaction methods, molecular cloning, differential colony hybridization, nucleotide sequencing, and a third hypervariable region (V3) peptide enzyme-linked immunoabsorbent assay were used to differentiate subjects infected with HIV-1 subtypes B, E, both, or neither. 58% of the men reported a heterosexual orientation outside of work and 34% were married. 72.1% reported inconsistent or no condom use with sex partners. 17 (16.5%) were infected with HIV. Of those infected, 16 (94%) had HIV-1 subtype E and 1 had subtype B.

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.

Measuring HIV-1 incidence in northern Thailand: prospective cohort results and estimates based on early diagnostic tests.

Measuring the incidence of the human immunodeficiency virus (HIV) is of vital importance but can be difficult and costly. We compared HIV-1 incidence measured directly from prospective cohort studies with rates derived from a method using the prevalence of HIV-1 antibody-negative, p24-antigen-positive individuals. Male and female commercial sex workers (CSWs) were enrolled and followed in separate cohort studies in northern Thailand between 1989 and 1994, and HIV incidence was measured by prospective follow-up of individuals seronegative at baseline. In 1991-1992 cross-sectional serosurveys were done among male and female CSWs in the same region; all HIV-1 antibody-negative subjects in these surveys were tested for p24 antigenemia. HIV incidence was estimated using the prevalence of p24 antigen and a model based on the mean duration of p24 antigenemia before HIV antibody detection. The cohort studies showed high initial incidence rates-23.8/100 person-years (PY) among female CSWs and 11.9/100 PY among male CSWs-but poor compliance with prospective follow-up. Subjects lost to follow-up appeared to be at greater risk of HIV seroconversion than those retained. The p24 antigen method estimate among female CSWs, 25.4%/year, was quite similar to the initial incidence rate found in the cohort. The estimate by the p24 antigen method was higher, 19.9%/year, among male CSWs than that measured prospectively. In populations with high rates of HIV transmission and in whom long-term follow-up is incomplete, estimates of incidence using p24 antigen prevalence among antibody-negative subjects can give useful and economical estimates of HIV incidence and allow for estimates of whether the incidence rates are similar in subjects successfully followed and those lost to follow-up.

The epidemiology of HIV and syphilis among male commercial sex workers in northern Thailand.

OBJECTIVE: To examine the prevalence and incidence of HIV and syphilis, and risk behaviors for these infections, among 1,172 male commercial sex workers (CSW) followed prospectively from 1989 to 1994 in Chiang Mai, northern Thailand. METHODS: Twice yearly visits were conducted by the Thai Ministry of Public Health at all cooperating gay bars and clubs (17 sites) in Chiang Mai City as part of a national HIV sentinel surveillance. Men and boys who agreed were followed prospectively. Sentinel visits included an interview, HIV pre-test counseling, HIV and syphilis serology, condom distribution, and referral for post-test counseling. Participation was voluntary, confidential, and individual HIV results were available only to participating subjects. A total of 219 CSW were seen at least twice, allowing for incidence estimates based on 100 person-years (PY). RESULTS: Median age of male CSW was 20 years. Median time of work as a CSW was 4 months. Most men (57.6%) described themselves as heterosexual. Median number of clients was 2.5 per week, and reported condom use with clients was low: 42% reported inconsistent or no condom use, while 58% reported always using condoms. Reactive Venereal Disease Research Laboratory results were 7.6%, overall, but showed a declining trend. HIV prevalence was 1.4% in June 1989, 13.9% in June 1990, and 20.1% in December 1993, and showed a significant increasing trend. There were 27 incident HIV infections in 227.3 PY of observation, for an overall incidence during the 4.5-year period of 11.9 per 100 PY (95% confidence interval, 7.42-16.38). CONCLUSION: Male CSW in northern Thailand are at high risk for HIV despite current prevention efforts. The majority are heterosexual, which may be an important epidemiologic link in the spread of HIV between male CSW users and heterosexual women in Thailand.

PIP: The first confirmed case of human immunodeficiency virus (HIV) infection in Thailand was that of a Thai male commercial sex worker (CSW) in 1985. Since that time, this disease has manifested itself among injecting drug users, female sex workers, and in the general heterosexual and homosexual population. This paper reports the findings of a 5-year Thai study in which 1172 male CSWs were studied at least once. The purpose of the study was to identify the prevalence, incidence, and risk behaviors of CSWs regarding HIV and syphilis. The HIV prevalence increased from 1.4% in 1989 to 20.1% by 1993. Overall, the HIV prevalence for the 5-year period was statistically significant at 16.6%. Syphilis for this same period was 7.6% HIV infections were confirmed using enzyme-linked immunosorbent assay (ELISA). Multivariate analysis was calculated using multiple logistic regression. All CSWs in this study were provided with HIV pre-test counseling, were subjected to HIV and syphilis serology, were given condoms, and were provided with a referral for post-test counseling. Of the 1172 men seen, 219 (18.6%) were seen more than once. 27 cases of HIV infection were confirmed in the latter group (12.3%). Heterosexual men were found to be at lower risk of contracting an HIV infection than homosexual men.