Chawalit Natpratan

Epidemiologic and biologic characterization of a cohort of human immunodeficiency virus type 1 highly exposed, persistently seronegative female sex workers in northern Thailand

Characterization of persons highly exposed to human immunodeficiency virus (HIV)-1 who remain uninfected may help define protective immunity. Seventeen HIV-1-seronegative Thai female sex workers (CSWs) with epidemiologic evidence of exposure to HIV-1 were studied for humoral immune responses and phenotypic and genotypic analyses of HLA class I and CCR5 allelic profiles. Infected CSWs and low-risk HIV-1-seronegative Thai women were controls. Highly exposed, persistently seronegative (HEPS) CSWs did not differ from HIV-infected CSWs in HIV risks, condom use, or sexually transmitted diseases. Significant differences were seen in humoral immune responses: gp160-specific IgA responses were detected in cervicovaginal lavage fluids in 6 of 13 HEPS CSWs but 0 of 21 seronegative subjects. All women had wild-type CCR5. HEPS CSWs were more likely to have the HLA-B18 phenotype and genotype than were matched controls (corrected P=.018). Epidemiologic exposure to HIV-1 without apparent infection, an unusual distribution of HLA class I alleles, and HIV-1 gp160-specific IgA responses suggest a biologic basis for this phenomenon.

Molecular methods for the diagnosis of genital ulcer disease in a sexually transmitted disease clinic population in Northern Thailand: Predominance of herpes simplex virus infection

A multiplex polymerase chain reaction (M-PCR) assay that simultaneously detects the three major causes of genital ulcer disease (GUD), Haemophilus ducreyi, Treponema pallidum, and herpes simplex virus, was used to evaluate swab specimens for 38 sequential patients with GUD at a Thai sexually transmitted disease clinic. Subjects received clinical diagnoses and syndromic treatment. Swab specimens for H. ducreyi cultures and M-PCR were obtained. No H. ducreyi cultures were positive. Of 38 M-PCR specimens, 31 (81.6%) were positive for HSV, 1 (2.3%) for both HSV and T. pallidum, and none for H. ducreyi or T. pallidum alone; 6 (15.8%) were negative for all 3 pathogens. Clinical diagnoses corresponded poorly to M-PCR findings; none of 5 suspected cases of chancroid were positive by M-PCR and none of 1 for syphilis, but 21 of 24 suspected herpes lesions were confirmed by M-PCR. Human immunodeficiency virus infection status was known for 24 of 38 subjects; 11 (45.8%) were seropositive, and all 11 had HSV by M-PCR. HSV appeared to be the most common pathogen overall.

Human immunodeficiency virus infection and self-treatment for sexually transmitted diseases among northern Thai men.

Background and Objectives: Self‐treatment for sexually transmitted diseases (STD) is common, but little studied, in Thailand, and its influence on human immunodeficiency virus (HIV) infection is unknown. Goals: To assess STD self‐treatment and self‐prophylaxis behaviors as well as HIV risks and serostatus among northern Thai men. Study Design: Cross‐sectional report from a cohort of military conscripts (N = 869). HIV and STD seroprevalence and reported risk behaviors, including STD history and antibiotic self‐treatment, were obtained. Associations between STDs and self‐treatment or prophylaxis and HIV infection were analyzed using t‐tests, odds ratios, and logistic regression. Results: The prevalence rate for HIV was 12.3%, and for syphilis it was 2.2%. Men who were seropositive for HIV were more likely to report having sex with commercial sex workers (OR 9.1), to have had an STD (OR 5.96), and to report inconsistent condom use with commercial sex workers (OR 3.13). Of 282 men reporting any STD, 65.2% treated themselves with antibiotics, and 8.5% used them before commercial sex. Among those who frequented commercial sex workers, 98.7% took preventive steps after sex by increasing urine output (69.2%), washing the genital area (28.9%), and using antibiotics (0.9%). Men reporting STD self‐treatment were less likely to be HIV infected (OR 0.53; 95% CI 0.31, 0.93). Conclusions: These men are attempting to prevent HIV and STDs. Self‐treatment with antibiotics may lower HIV risks associated with bacterial STD in a high‐prevalence population.

Diversification of Subtype E Human Immunodeficiency Virus Type 1 env in Heterosexual Seroconverters from Northern Thailand

The C2-V3 region of the human immunodeficiency virus (HIV)-1 env was determined from 15 northern Thailand seroconverters between 1993 and 1995. Similar sequences were also determined from 18 seroconverting injection drug users in Baltimore. All seroconverters from northern Thailand were infected with subtype E HIV-1 on the basis of env sequences. Intersubject viral DNA distances increased from 2.3% in asymptomatic HIV-1-infected subjects characterized between 1990 and 1992 to 7.8% in these more recent seroconverters from Thailand. On the other hand, sequences from 18 seroconverters from Baltimore had a mean intersubject distance of 13.2%. The genetic diversity within HIV-1 subtype E in seroconverters in Thailand has increased significantly but is still less than that observed in HIV-1 from seroconverters in the United States, where the epidemic of HIV-1 infection is more mature. These results suggest that continued monitoring of the molecular epidemiology of HIV-1 infection in Thailand will be important for HIV vaccine development and evaluation.

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.

Addressing the high prevalence of gonorrhoea and chlamydia among female sex workers in Indonesia: results of an enhanced, comprehensive intervention

Objectives The authors developed a comprehensive STI-control programme to decrease gonorrhoea and chlamydia prevalence, and increase consistent condom use among brothel-based sex workers in Indonesia. Methods The STI-control programme for brothel-based sex workers in Bintan Island (Riau Islands) and Salatiga (Central Java) included (1) provision of adequate drugs for gonorrhoea and chlamydia as periodic presumptive treatment (PPT) followed by syndromic treatment; (2) condom-use promotion by involving the local community and ensuring sufficient condom supply. Endocervical samples were collected and tested for gonorrhoea and chlamydia by PCR. Cross-sectional assessments of gonorrhoea and chlamydia prevalence, and consistent condom use with clients in the last week were made at several time points for sex workers attending the STI clinic. Results 580 sex workers participated in the programme. A steady decrease in prevalence was observed for gonorrhoea (36.1–7.6%) and chlamydia (33.7–10.2%) (both p<0.01) among sex workers in Bintan from March 2008 until June 2009. Sex workers in Salatiga showed a sharp initial decrease in prevalence, followed by an increase after provision of the old drug regimen. Gonorrhoea and/or chlamydia prevalence among those who had received at least one PPT round was lower compared with that in newcomers (p<0.01). The proportion of sex workers reporting consistent condom use doubled to 40% in June 2009 compared with November 2007 (p<0.01). Conclusion The STI-control programme was effective in reducing infection prevalence and increasing condom use among sex workers. This intervention has been scaled up and may decrease national STI levels and reduce HIV transmission.

Personal History of Voluntary HIV Counseling and Testing (VCT) Among Adults Aged 19–35 Years Living in Peri-urban Communities, Chiang Mai, Northern Thailand

This study investigates the self-reported history of HIV voluntary counseling and testing (VCT) among adults, aged 19–35 years, in northern Thailand. Participants were interviewed about their HIV testing history and risk behavior. Overall, 47% of 2251 participants had previously been tested, of whom 64% were tested at government clinics. Of those tested at private clinics, 50% reported not receiving pre- and post-test counseling, compared to 15% of those tested in government clinics. Ten percent of those tested had not received their test results. Among those who had never been previously tested for HIV, 66% believed they were not at risk, although 1.5% (2.7% among men) were HIV infected. Although VCT is widely available and utilized by the population of northern Thailand, substantial numbers of HIV infected persons have not been tested for HIV and among those tested many have not received comprehensive counseling. A Thai government policy enforcing effective counseling to accompany HIV testing is urgently needed.

Syphilis among female sex workers in Indonesia: need and opportunity for intervention

Objective To study the prevalence and factors associated with syphilis among female sex workers (FSWs) in Indonesia. Methods Direct and indirect FSWs were sampled in 10 major cities in Indonesia. A behavioural survey was conducted and samples obtained and tested for HIV (Bioline and Determine) and syphilis (RPR and Determine). Syphilis prevalence and potential factors associated with syphilis were assessed in bivariable and multivariable analysis. Syphilis prevalence among brothel-based sex workers from previous surveillance in 2003 and 2005 was compared to 2007. Results A total of 2436 direct and 1888 indirect FSWs participated in both the behavioural and biomarker surveys. Prevalence of active syphilis (RPR≥1:8) was high among direct and indirect FSWs (7.5% vs 3.1%) and was not lower among those who had visited an STI clinic in the last 3 months. Prevalence of active syphilis was lower among those who had received at least one dose of a prior periodic presumptive treatment programme (PPT) for chlamydia and gonorrhoea with 1 g azithromycin and 400 mg cefixime compared to those who had not received PPT (3.9% vs 6.0%; p=0.008). Older age (AOR=1.4), longer duration of sex work (AOR=1.7) and PPT (AOR=0.6) were associated with active syphilis in multivariable analysis. Syphilis prevalence among brothel-based FSWs increased from 2005 to 2007 (7.8% vs 14.5%; p<0.001). Conclusions Syphilis prevalence among FSWs in Indonesia was high and increased from 2005 to 2007. Receipt of PPT was associated with lower syphilis prevalence. Current syphilis control programmes need to be evaluated and the possibility of alternative syphilis treatment with azithromycin explored.

Simultaneous use of multiple condoms among male cambodian military personnel visiting female sex workers

Objectives: To estimate the prevalence of simultaneous use of multiple condoms (SUMC) and identify the characteristics of the multiple condoms users. Study Design: Cross-sectional survey among military men from a purposively selected Cambodian military region. Military men were interviewed face to face. Results: From the 1638 respondents, 40% never had sex with female sex workers (FSWs), 55% had used condom(s), and 5% had unprotected sex at their last encounter with a FSW. Among those reporting sex with FSWs, 21% had used multiple condoms simultaneously at their last sex with a FSW. Conclusion: Compared with single condom users, multiple condom users were younger, had lower rank, had first sex more recently, had lower knowledge of HIV transmission, had received less HIV peer-education sessions, were more likely to have visited multiple FSWs, and were more likely to have sought their HIV serostatus. As it is unknown if SUMC increases or decreases condom effectiveness, more research is needed to investigate the effect of SUMC on condom failure rates.

Hepatitis B immunization: a potential incentive to HIV vaccine trial participation in Thailand?

To assess the effectiveness of hepatitis B immunization as an incentive to retention in HIV seroincidence studies and future HIV vaccine trials in northern Thailand, subjects enrolled in three HIV seroincidence cohorts were screened for hepatitis B markers and seronegatives were offered free hepatitis B immunization. Cohorts studied included female commercial sex workers (CSWs), male sexually transmitted disease (STD) patients, and recently discharged military conscripts. Subjects who agreed to the immunization program were compared with those not enrolled to determine the utility of immunization as an incentive to cohort retention. Full immunization was achieved for 273 (89.5%) of 305 vaccinees; only 323 (60.6%) of 533 subjects not immunized completed the same follow-up visits (OR = 1.49, 95% and CI = 1.27, 1.75). Hepatitis B vaccination was a significant incentive for completion of the follow-up program. The vaccination program had the greatest effect on the CSWs; a similar effect was seen for male STD patients, but not for discharged conscripts. Despite the immunization program, follow-up rates at 12 months were similar in the immunized and nonimmunized groups.