Methamphetamine users in northern Thailand: changing demographics and risks for HIV and STD among treatment-seeking substance abusers.

Our objective was to determine sociodemographic, sexual and drug-use-related risk factors among methamphetamine (MA) users presenting for drug treatment in northern Thailand. Patients admitted for drug detoxification for MA and other drugs were studied cross-sectionally for risk factors associated with substance abuse and blood-borne and sexually transmitted pathogens. In all, 1865 (200 women) patients treated for MA, opiate, and mixed substance abuse between 1 February 1999 and 31 January 2000 completed all study procedures. Among 1865 participants, 750 (40.2%) were admitted for MA detoxification and 1115 (59.8%) for opiate (heroin, opium, or both) treatment. MA users were significantly younger, better educated, more likely to be Thai than highland ethnic minorities, and had significantly different sexual risks and sexually transmitted disease rates, including lower syphilis seropositivity and higher chlamydial prevalence, than persons admitted for opiate or mixed drug treatment. For those who reported MA use only, use by injection was rare and HIV infections significantly less common than among all other drug users. Thailand is undergoing an epidemic of MA use. These young users are a strikingly different population from opiate/heroin users in northern Thailand. MA users had higher rates of chlamydia infection than opiate users, reflecting their young age, and HIV rates in this population were lower than injecting drug users, but still elevated. MA use is a serious public health problem in Thailand and both improved prevention and treatment methodologies are urgently needed.

Risk analysis of the exposure to GB virus C/hepatitis G virus among populations of intravenous drug users, commercial sex workers and male outpatients at STD clinic in Chiang Mai, Thailand: a cross-sectional case-control study.

An exposure to GB virus C/hepatitis G virus (GBV-C/HGV) was studied among populations at risk for blood and sexual exposure to analyze risk factor of the transmission of the virus. Blood samples were drawn from 98 intravenous drug users (IVDU), 100 female high-class commercial sex workers (CSW) and 50 male outpatients (MOP) at a sexually transmitted diseases (STD) clinic in Chiang Mai, Thailand. These blood samples were analyzed for GBV-C/HGV RNA; antibodies against second envelope protein of GBV-C/HGV (anti-E2); anti-hepatitis C virus antibody (HCV-Ab); hepatitis B core antibody (HBcAb); and antibodies against human immunodeficiency virus (HIV-Ab). Prevalences of GBV-C/HGV RNA, anti-E2, HCV-Ab, HBcAb and HIV-Ab were 27.6%, 16.3%, 84.7%, 76.5% and 45.0% in IVDU; 0%, 21.5%, 2.0%, 72.0% and 11.0% in CSW; 6.0%, 13.6%, 0%, 64.0% and 14.0% in MOP. While the prevalence of GBV-C/HGV RNA was higher in IVDU than in CSW and MOP, comparable prevalences of anti-E2 among the three populations were found. Intravenous drug injection showed association with GBV-C/HGV RNA, while history of STD associated with anti-E2. In conclusion, intravenous drug injection and STD were found to be risk factors for the previous exposure to GBV-C/HGV, but STD did not increase the risk of the GBV-C/HGV viraemia.

Socio-demographic and drug use factors associated with HIV-1 recombinants and dual infections in Northern Thai drug users: associations of risk with genetic complexity.

BACKGROUND: Dual infection with diverse HIV strains can foster the emergence of recombinants. The resulting increase in viral genetic diversity is a major challenge for vaccine development HIV treatment. In this study we aim to investigate the socio demographic factors associated with an increasing level of genetic diversity among HIV strains in a population of drug-users in Northern Thailand. METHODS: From 1999 through 2000, 2231 volunteers were enrolled in the Opiate-Users Research in Chiang Mai, Thailand. HIV subtype analysis was conducted among those HIV-1 seropositive (n=347) using a multi-region hybridization assay. Social and demographic variables were assessed using a structured questionnaire. RESULTS: Overall, 336/347 (96.8%) of the samples could be typed. 81.8% were CRF01_AE, 3.9% were subtype B, 9.2% were recombinants (mostly between CRF01_AE and B) and 5.1% were dual infections. Dual infections were more frequent among those with a lower education level (AOR: 5.2; 95% CI 1.4-20.3), those who have initiated injecting in the last 3 years (AOR: 3.9; 95% CI 1.1-14.6), and those reporting frequent needle sharing in the last 3 months (AOR: 7.0; 95% CI 1.5-34.1). Both recombinant strains and dual infection were more frequent among those reporting frequent needle sharing in the last 3 months (AOR: 5.3; 95% CI 1.6-17.1). CONCLUSION: To limit the expanding complexity of HIV-1 strains, early intervention should be aimed at reduction in needle sharing, especially among new intravenous drug users.

HIV incidence rates among drug users in northern Thailand, 1993-7.

Drug use is a major mode of HIV transmission in Thailand. This study determined HIV incidence rates among drug users in a regional drug treatment centre in northern Thailand. A retrospective cohort of repeatedly-hospitalized drug users between 1993 and 1997 was formed and HIV incidence rates were calculated. The overall incidence was 11.44 per 100 person-years of observation. Gender, age, religion, ethnicity, education, employment, income, reasons for drug use, type of drugs, mode of use, spending on drugs, and referral for treatment are associated with HIV incidence. However, there are no associations between HIV incidence and history of treatment and mode of discharge from the centre. This implies that current treatment modality has no impact on HIV infection risk and other therapeutic approaches should be explored.

HIV-1 incidence among opiate users in northern Thailand.

The incidence of human immunodeficiency virus type 1 (HIV-1) infection among opiate users was determined in a retrospective cohort of 436 patients with multiple admissions to the only inpatient drug treatment program in northern Thailand between October 1993 and September 1995. During 323.4 person-years of follow-up, 60 patients presenting for detoxification acquired HIV-1 infection, for a crude incidence rate of 18.6 per 100 person-years (95% confidence interval 14.4-23.9). All seroconverters were male. HIV-1 incidence varied by the current route of drug administration: 31.3 per 100 person-years for injectors and 2.8 per 100 person-years for noninjectors (smoking and ingestion). Significant differences were found by ethnicity: HIV-1 incidence was 29.3 per 100 person-years for Thai lowlanders and 8.5 per 100 person-years for hill tribes. Multivariate relative risk estimates showed that injecting opiates (vs. use by other routes), being unmarried, being under age 40 years, being a Thai lowlander, having a primary and secondary education, and being employed in the business sector were each independently associated with human immunodeficiency virus seroconversion. This HIV-1 incidence rate is double that reported for Bangkok and suggests that prevention and control programs for drug users need to be expanded throughout Thailand. Improved availability of more-effective treatment regimens and increased access to sterile injection equipment are needed to confront the HIV-1 epidemic among opiate users in northern Thailand.

PIP: The incidence of HIV-1 infection among opiate users was assessed in a retrospective cohort of 436 patients with multiple admissions to the only inpatient drug treatment program in northern Thailand between October 1993 and September 1995. During 323.4 person-years of follow-up, 60 patients presenting for detoxification acquired HIV-1 infection, for a crude incidence rate of 18.6/100 person-years. All seroconverters were male. HIV-1 incidence varied by the current route of drug administration: 31.3/100 person-years for injectors and 2.8/100 person-years among those who smoked or ingested the drug. HIV-1 incidence was 29.3/100 person-years for Thai lowlanders and 8.5/100 person-years for hill tribes. Multivariate analysis found that injecting opiates, being unmarried, being under age 40 years, being a Thai lowlander, having a primary and secondary education, and being employed in the business sector were each independently associated with HIV seroconversion. The HIV-1 incidence rate in this population is double that reported for Bangkok. As such, HIV prevention and control programs for drug users need to be expanded throughout Thailand. Moreover, improved availability of more effective treatment regimens and increased access to sterile injection equipment are needed to confront the HIV-1 epidemic among opiate users in northern Thailand.