The epidemiology of HIV infection and AIDS in Thailand

Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia

BACKGROUND

Universal access to first-line antiretroviral therapy (ART) for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce.

METHODS AND FINDINGS

We developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. We show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains.

CONCLUSIONS

If viral load testing of people on ART is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.

An HIV epidemic is ready to emerge in the Philippines

Background

The state of the HIV epidemic in the Philippines has been described as "low and slow", which is in stark contrast to many other countries in the region. A review of the conditions for HIV spread in the Philippines is necessary.

Methods

We evaluated the current epidemiology, trends in behaviour and public health response in the Philippines to identify factors that could account for the current HIV epidemic, as well as to review conditions that may be of concern for facilitating an emerging epidemic.

Results

The past control of HIV in the Philippines cannot be attributed to any single factor, nor is it necessarily a result of the actions of the Filipino government or other stakeholders. Likely reasons for the epidemic's slow development include: the country's geography is complicated; injecting drug use is relatively uncommon; a culture of sexual conservatism exists; sex workers tend to have few clients; anal sex is relatively uncommon; and circumcision rates are relatively high.

In contrast, there are numerous factors suggesting that HIV is increasing and ready to emerge at high rates, including: the lowest documented rates of condom use in Asia; increasing casual sexual activity; returning overseas Filipino workers from high-prevalence settings; widespread misconceptions about HIV/AIDS; and high needle-sharing rates among injecting drug users.

There was a three-fold increase in the rate of HIV diagnoses in the Philippines between 2003 and 2008, and this has continued over the past year. HIV diagnoses rates have noticeably increased among men, particularly among bisexual and homosexual men (114% and 214% respective increases over 2003-2008). The average age of diagnosis has also significantly decreased, from approximately 36 to 29 years.

Conclusions

Young adults, men who have sex with men, commercial sex workers, injecting drug users, overseas Filipino workers, and the sexual partners of people in these groups are particularly vulnerable to HIV infection. There is no guarantee that a large HIV epidemic will be avoided in the near future. Indeed, an expanding HIV epidemic is likely to be only a matter of time as the components for such an epidemic are already present in the Philippines.

Inconsistent condom use among young men who have sex with men, male sex workers, and transgenders in Thailand

Young men who have sex with men (MSM) are at risk for HIV infection. We investigated inconsistent condom use among 827 sexually active young MSM (15-24 years), enrolled using venue-day-time sampling in Bangkok, Chiang Mai and Phuket, Thailand. Data was collected using palmtop computer-assisted self-interviewing. Of participants, 33.1% were regular MSM, 37.7% were male sex workers (MSWs) and 29.1% were transgenders (TGs). Of MSM, 46.7%, of MSWs, 34.9% and of TGs, 52.3% reported recent inconsistent condom use. In multivariate analysis, receptive anal intercourse (MSM, MSWs), receptive and insertive anal intercourse, living alone and a history of sexual coercion (MSWs), not carrying a condom when interviewed (MSM, TGs), lower education, worrying about HIV infection and a history of sexually transmitted infections (TGs) were significantly and independently associated with inconsistent condom use. Interventions for young MSM are needed and must consider the distinct risk factors of MSM, MSWs, and TGs.

Regional variations in HIV disclosure in Thailand: implications for future interventions

People living with HIV (PLH) in Thailand face tremendous challenges, including HIV disclosure. With the advent of antiretroviral (ARV) therapy in Thailand, the positive benefits of HIV disclosure are becoming more salient. However, there are regional variations in the levels of HIV disclosure in Thailand. We examined and compared the levels of HIV disclosure in Northern and Northeastern Thailand. PLH (N = 410) were recruited from four district hospitals in the North and the Northeast. More PLH in the North reported disclosing HIV status to at least one family member in the household. PLH in the Northeast reported significantly lower levels of HIV disclosure within family and outside of family. HIV disclosure remains a significant challenge in Thailand, especially in the Northeast. We propose future interventions focusing on HIV disclosure to address the specific concerns and barriers to HIV disclosure, taking into account the regional differences in HIV disclosure.

HIV type 1 molecular epidemiology among high-risk clients attending the Thai Red Cross Anonymous Clinic in Bangkok, Thailand

Several studies have reported an increasing number of non-CRF01_AE infections in high-risk groups in Thailand suggesting a more complex HIV-1 epidemic. This study assessed the complexity of the HIV epidemic among high-risk clients tested for HIV-1 at the Thai Red Cross Anonymous Clinic (TRCAC) between July 1, 2006 and February 28, 2007. HIV-1 genotypes were determined from plasma of infected subjects (n = 401) by the multiregion hybridization assay (MHAbce, v.2). Univariate and multivariate logistic regression analyses were used to determine risk factors associated with HIV prevalence and non-CRF01_AE infection. The estimated overall HIV prevalence was 14.1%: 25.3% among men who have sex with men (MSM), 18.4% among heterosexual women, and 9.6% among heterosexual men. Among the risk factors found to be associated with HIV prevalence were age (25-29 years), risk behavior (MSM), marital status (not single), education (less than high school), and inconsistent condom use. Overall, non-CRF01_AE strains accounted for 18.9% of the infections: 25.3% among MSM and 14.8% and 20.4% among heterosexual women and men, respectively. Our results indicate a concentrated and genetically complex HIV epidemic among Thai MSM. These findings advocate for targeted intervention and prevention measures among high-risk populations in Thailand.

Incarceration experiences among a community-recruited sample of injection drug users in Bangkok, Thailand

Background

Since 2003 Thailand has waged an aggressive "war on drugs" campaign focused on arresting and incarcerating suspected drug users and dealers. However, little is known about incarceration experiences among IDU in the wake of the recent war on drugs. Therefore, we sought to examine incarceration experiences among IDU in Bangkok, Thailand.

Methods

We examined the prevalence of incarceration among community-recruited IDU participating in the Mitsampan Community Research Project. Multivariate logistic regression was used to identify factors associated with a self-reported history of incarceration. We also examined the prevalence of injection drug use and syringe sharing within prisons.

Results

252 IDU were recruited in August 2008; 66 (26.2%) were female and the median age was 36.5 years. In total, 197 (78.2%) participants reported a history of incarceration. In multivariate analyses, reporting a history of incarceration was associated with a history of compulsory drug treatment (adjusted odds ratio [AOR] = 4.93; 95% confidence interval [CI]: 1.95 - 12.48), non-fatal overdose (AOR = 3.69; 95%CI: 1.45 - 9.39), syringe sharing (AOR = 2.20; 95%CI: 1.12 - 4.32), and female gender (AOR = 0.41; 95%CI: 0.20 - 0.82). Among those who reported a history of incarceration, 59 (29.9%) reported injection drug use in prison, and 48 (81.4%) of these individuals reported sharing syringes in prison. Incarceration was not associated with the number of injections performed in the previous week (p = 0.202).

Conclusion

Over three-quarters of the IDU participating in this study reported a history of incarceration, and 30% of these individuals reported injection drug use within prison. Further, an alarmingly high level of syringe sharing within prison was reported, and incarceration was not associated with reductions in drug use. These findings provide further evidence of the need for community diversion strategies, as well as harm reduction programs, in Thai prisons.

Vaccination with ALVAC and AIDSVAX to prevent HIV-1 infection in Thailand

BACKGROUND

The development of a safe and effective vaccine against the human immunodeficiency virus type 1 (HIV-1) is critical to pandemic control.

METHODS

In a community-based, randomized, multicenter, double-blind, placebo-controlled efficacy trial, we evaluated four priming injections of a recombinant canarypox vector vaccine (ALVAC-HIV [vCP1521]) plus two booster injections of a recombinant glycoprotein 120 subunit vaccine (AIDSVAX B/E). The vaccine and placebo injections were administered to 16,402 healthy men and women between the ages of 18 and 30 years in Rayong and Chon Buri provinces in Thailand. The volunteers, primarily at heterosexual risk for HIV infection, were monitored for the coprimary end points: HIV-1 infection and early HIV-1 viremia, at the end of the 6-month vaccination series and every 6 months thereafter for 3 years.

RESULTS

In the intention-to-treat analysis involving 16,402 subjects, there was a trend toward the prevention of HIV-1 infection among the vaccine recipients, with a vaccine efficacy of 26.4% (95% confidence interval [CI], -4.0 to 47.9; P=0.08). In the per-protocol analysis involving 12,542 subjects, the vaccine efficacy was 26.2% (95% CI, -13.3 to 51.9; P=0.16). In the modified intention-to-treat analysis involving 16,395 subjects (with the exclusion of 7 subjects who were found to have had HIV-1 infection at baseline), the vaccine efficacy was 31.2% (95% CI, 1.1 to 52.1; P=0.04). Vaccination did not affect the degree of viremia or the CD4+ T-cell count in subjects in whom HIV-1 infection was subsequently diagnosed.

CONCLUSIONS

This ALVAC-HIV and AIDSVAX B/E vaccine regimen may reduce the risk of HIV infection in a community-based population with largely heterosexual risk. Vaccination did not affect the viral load or CD4+ count in subjects with HIV infection. Although the results show only a modest benefit, they offer insight for future research. (ClinicalTrials.gov number, NCT00223080.)

Gender and access to HIV testing and antiretroviral treatments in Thailand: why do women have more and earlier access?

In the recent scale-up of antiretroviral treatment, gender differences in access to treatment have been reported. In Thailand, as the HIV epidemic became more generalised, there has been a shift from men being disproportionately affected to increased vulnerability of women. In 2007, the Living with Antiretrovirals (LIWA-ANRS 12141) study investigated the gender distribution of all adult patients receiving antiretroviral therapy (N=513 patients) in four community hospitals in northern Thailand and factors influencing the disparities observed. From this retrospective life-event history survey, we found that proportionately more women (53%) were receiving antiretroviral therapy than men, an unexpected result for a country with a higher proportion of infections among men. They were more likely to initiate treatment within one year of diagnosis and were at a more advanced stage of the disease compared to women. This gender distribution is partly explained by the evolving dynamics of the HIV epidemic, initial prioritization of mothers for treatment and earlier access to HIV testing for women. These issues are also entangled with gender differences in the reasons and timing to HIV testing at the individual level. This study found that the majority of men underwent HIV testing for health reasons while the majority of women were tested following family events such as a spouse/child death or during pregnancy. Further qualitative research on gender specific barriers to HIV testing and care, such as perceived low risk of infection, poor access to medical care, lack of social support, actual or anticipated HIV/AIDS-related stigma would provide greater insight. In the meantime, urgent efforts are needed to increase access to voluntary counselling and testing inside and outside the family setting with targeted interventions for men.

Twenty-five years of HIV: lessons for low prevalence scenarios

During the initial quarter century since the discovery of HIV, international response has focused on high prevalence scenarios and concentrated epidemics. Until recently, the theoretical underpinnings of HIV prevention were largely based on these responses-the assumption that inadequate responses to concentrated epidemics within low prevalence populations could rapidly lead to generalized epidemics. The limits of these assumptions for HIV prevention in low prevalence scenarios have become evident. While examples of rapid HIV diffusion in once low prevalence scenarios exist, emergence of generalized epidemics are less likely for much of the world. This paper reviews several key issues and advances in biomedical and behavioural HIV prevention to date and highlights relevance to low prevalence scenarios.

Incidence of HIV and sexually transmitted infections and risk factors for acquisition among young methamphetamine users in northern Thailand

BACKGROUND

Southeast Asia is experiencing an epidemic of methamphetamine use, a drug associated with risky sexual behaviors, putting a large segment of the population at increased risk for sexually transmitted infections (STIs) and HIV and in need of prevention efforts. Incidence estimates of STIs are rare in Southeast Asia, especially among newer risk groups.

STUDY DESIGN

We enrolled methamphetamine users aged 18 to 25 years in a 12-month randomized behavioral intervention trial in Chiang Mai, Thailand in 2005. Behavioral questionnaires were administered at visits every 3 months, and biologic specimens were collected at baseline and 12 months to test for common STIs (chlamydia, gonorrhea, HSV-2, and HIV). Poisson regression with robust variance was used to determine risk factors for incident STIs.

RESULTS

Overall, 12.7% of 519 participants acquired at least 1 STI. Chlamydia was the most common (10.6%), followed by HSV-2 (4.0%), gonorrhea (2.9%), and HIV (0.6%). Risk factors for both men and women included self-reported incarceration and having a casual sex partner during follow-up, and having a prevalent STI at baseline. Additionally, among women, having 2 or more heterosexual partners, and among men, having a greater frequency of drunkenness were risk factors for STI acquisition.

CONCLUSIONS

Although HIV incidence is low in this population, incidence of other STIs is high compared with previous studies of young Thai adults. Risk factors for acquisition emphasize the need for new prevention strategies targeted toward current populations at risk.

Estimating the date of origin of an HIV-1 circulating recombinant form

HIV is capable of frequent genetic exchange through recombination. Despite the pandemic spread of HIV-1 recombinants, their times of origin are not well understood. We investigate the epidemic history of a HIV-1 circulating recombinant form (CRF) by estimating the time of the recombination event that lead to the emergence of CRF33_01B, a recently described recombinant descended from CRF01_AE and subtype B. The gag, pol and env genes were analyzed using a combined coalescent and relaxed molecular clock model, implemented in a Bayesian Markov chain Monte Carlo framework. Using linked genealogical trees we calculated the time interval between the common ancestor of CRF33_01B and the ancestors it shares with closely related parental lineages. The recombination event that generated CRF33_01B (t(rec)) occurred sometime between 1991 and 1993, suggesting that recombination is common in the early evolutionary history of HIV-1. The proof-of-concept approach provides a new tool for the investigation of HIV molecular epidemiology and evolution.

The changing face of the HIV epidemic in Taiwan: a new challenge for public health policy strategies

The goals of this study were to examine trends, risk factors, and survival rates of people diagnosed with HIV/AIDS. We used national surveillance data reported to the Taiwan Center for Disease Control (Taiwan CDC). The subjects of this study were all confirmed HIV and AIDS cases in Taiwan. From 1990 through 2005, the number of people that have been reported to have HIV/AIDS is 9961. Among individuals with HIV/AIDS, the male-to-female ratio was 11:1, the median age was 32 years. The number of HIV and AIDS diagnoses increased significantly for both men and women during the study period. The number of HIV cases among men who have sex with men (MSM) increased from 24 in 1990 to 527 in 2005, while diagnoses among injection drug users (IDUs) rose rapidly from 3 in 1990 to 2450 in 2005. The incidence-to-prevalence ratio (IPR) has risen sharply in recent years and has exceeded the epidemic threshold (IPR(t) = 0.1) for IDUs, indicating a growing epidemic. The corresponding hazard ratios for the highly active antiretroviral therapy (HAART) era versus pre-HAART era in the earlier and late HIV diagnosis groups were 0.45 (95% confidence interval [CI] 0.36-0.54) and 0.39 (95% CI 0.31-0.49), respectively. There was no significant difference in the survival rate of HIV testers. The increasing number of HIV infection places Taiwan among the worst IDU-concentrated epidemic areas in Asia. HIV intervention and prevention strategies, especially targeting IDUs, are urgently needed to reduce the ongoing spread of HIV infections in Taiwan.

Factors associated with incarceration and incident human immunodeficiency virus (HIV) infection among injection drug users participating in an HIV vaccine trial in Bangkok, Thailand, 1999-2003

AIMS

To determine if incarceration was associated with human immunodeficiency virus (HIV) infection and identify risk factors for incarceration among injection drug users (IDUs) participating in an HIV vaccine trial in Bangkok.

DESIGN

The AIDSVAX B/E HIV vaccine trial was a randomized, double-blind, placebo-controlled study. A proportional hazards model was used to evaluate demographic characteristics, risk behavior and incarceration as predictors of HIV infection and generalized estimation equation logistic regression analysis to investigate demographic characteristics and risk behaviors for predictors of incarceration.

SETTING

The trial was conducted in Bangkok Metropolitan Administration drug-treatment clinics, 1999-2003.

PARTICIPANTS

A total of 2546 HIV-uninfected IDUs enrolled in the trial.

MEASUREMENTS

HIV testing was performed and an interviewer-administered questionnaire was used to assess risk behavior and incarceration at baseline and every 6 months for a total of 36 months.

FINDINGS

HIV incidence was 3.4 per 100 person-years [95% confidence interval (CI), 3.0-3.9] and did not differ among vaccine and placebo recipients. In multivariable analysis, being in jail (P < 0.04), injecting (P < 0.0001), injecting daily (P < 0.0001) and sharing needles (P = 0.02) were associated with HIV infection and methadone maintenance was protective (P = 0.0006). Predictors of incarceration in multivariable analysis included: male sex (P = 0.04), younger age (P < 0.0001), less education (P = 0.001) and being in jail (P < 0.0001) or prison (P < 0.0001) before enrollment.

CONCLUSIONS

Among IDUs in the AIDSVAX B/E trial, incarceration in jail was associated with incident HIV infection. IDUs in Thailand remain at high risk of HIV infection and additional prevention tools are needed urgently. HIV prevention services, including methadone, should be made available to IDUs.

Cross-reactive T cell responses in HIV CRF01_AE and B'-infected intravenous drug users: implications for superinfection and vaccines

Abstract We previously observed limited cross-reactive T cell responses in two HIV-1-superinfected injection drug users (IDUs) before superinfection [Ramos A, et al.: J Virol 2002;76(15):7444-7452]. To elucidate the role of such responses in superinfection we examined cross-reactive T cell responses in IDUs infected with a single HIV-1 subtype. In this study, IFN-gamma ELISPOT assays were performed using recombinant vaccinia constructs and peripheral blood mononuclear cells (PBMCs) from 43 IDUs singly infected with CRF01_AE or B' from the same cohort as the superinfected IDUs. PBMCs were from time points corresponding to pre- (early) or post- (late) superinfection in the superinfected IDUs. We observed that most singly infected IDUs had cross-reactivity in samples from early (84% of CRF01_AE and 78% of B'-infected IDUs) and late (96% of CRF_01AE and 77% of B'-infected IDUs) time points. Frequent homologous reactivity at early (67% of CRF-01AE and 100% of B') and late (84% of CRF01_AE-infected and 100% of B'-infected IDUs) time points was also observed. Cross-reactive responses were predominantly to Pol and were broader and higher in CRF01_AE than in B'-infected IDUs (medians of 825 vs. 90 and 585 vs. 60 spot-forming units/10(6) PBMCs at early and late time points, respectively). Our results show that cross-reactive responses were more prevalent with greater height and breadth in singly infected IDUs than previously observed in corresponding collection time points of superinfected IDU. Thus, low or absent cross-reactivity may have contributed to the previously observed superinfections. These data are relevant for understanding superinfection and improving vaccine design.

"HIV is irrelevant to our company": everyday practices and the logic of relationships in HIV/AIDS management by Japanese multinational corporations in northern Thailand

Multinational corporations (MNCs) are important participants in workplace initiatives on HIV/AIDS as they collaborate with international organizations to globally promote various policies and guidelines. To date, MNCs have enacted the majority of such initiatives in North America, Europe and South Africa, but we have little information on how MNCs elsewhere, especially in Japan, have responded to the issue of HIV/AIDS in the workplace. This study examines the actual on the ground situation of HIV/AIDS management in Japanese MNCs, specifically investigating everyday corporate practices in the context of internal interactions and relationships and the resulting practices and outlook concerning HIV/AIDS. It is based on a secondary analysis of ethnographic case studies conducted in 10 Japanese-affiliated companies in northern Thailand. Japanese managers, Thai managers and ordinary Thai workers all considered HIV/AIDS to be "irrelevant" to their company and/or themselves. HIV/AIDS measures in the companies were limited to provision of information. This perception and management of HIV/AIDS developed from their everyday interactions governed by the logic of relationships in the companies. In these interactions, they categorized others based on their ascriptive status, primarily based on class, ethnicity and nationality. They sought scapegoat groups that were lower than them in the class- and ethnicity/nationality-based hierarchical system, and cast the risk of HIV infection upon the scapegoat groups, thus reducing their own sense of risk. The paper shows that the relational logic, not ideals or principles, influences their views of and actions concerning HIV/AIDS management in the companies. This is why Japanese companies are unable to deal with HIV/AIDS in terms of international policies and guidelines that are based on the logic of human rights and the logic of business principles. The results suggest a need for international policymakers to pay more attention to everyday practices in the actual field of policy dissemination.

The epidemic origin and molecular properties of B': a founder strain of the HIV-1 transmission in Asia

OBJECTIVE

To clarify the epidemic origin and molecular properties of the B' subtype that is an important strain in the HIV-1 epidemic in Asia.

DESIGN

The genealogical relationship between the B' and B subtype was investigated with two globally representative datasets covering the gag and env regions. B' sequences were identified, from which the epidemic origin, population genetics and the signature mutation sites of the B' subtype were inferred.

METHODS

Two globally representative datasets were compiled, using phylogenetic methods. Through coalescent-based analysis, the genealogical relationship between the B' and B subtypes was investigated. The divergence times and population genetic parameters of B' were estimated in a Bayesian framework using Markov Chains Monte Carlo sampling under a relaxed molecular clock method. Additionally, molecular properties of the B' were identified by performing comparative sequence analysis with the HIV-1 M group.

RESULTS

About 15 years later after the B subtype began to spread, the B' diverged from the B subtype. The demographic history of B' was reconstructed, and the epidemic of B' was estimated to originate around 1985. Eight and nine distinct signature mutation sites, unique to B', were found around the p17 and V3 regions, respectively.

CONCLUSION

Our research is the first large-scale investigation on HIV-1 B' at a global level and provides a deep insight into one of the founder strains of HIV-1 epidemic in Asia. Our results provide an important reference for HIV scientists, public health officials and HIV vaccine designers.

Clinical presentations of newly diagnosed HIV-infected patients at a university hospital in Bangkok, Thailand

BACKGROUND

Epidemiology and clinical features of newly diagnosed HIV-infected patients vary and depend on period of time and geographical area.

METHODS

A retrospective review was conducted in adults with positive HIV antibody testing between January and December 2006 at a university hospital setting.

RESULTS

Prevalence of HIV infection was 1.0%. There were 221 patients with a median age of 35.5 (range, 15.8-72.3) years, and 57% were males. The most common risk of HIV acquisition was heterosexual (63.8%). The most common reason for HIV testing was preoperative screening (41.2%). Of all, 52.9%, 37.1%, and 10% were diagnosed as AIDS, asymptomatic, and symptomatic patients, respectively. Median CD4 count at HIV diagnosis was 260 (range, 6-1284) cells/mm(3). AIDS-defining illnesses were found in 35.7%. Overall mortality rate was 1.8%.

CONCLUSIONS

More than half of newly diagnosed HIV-infected patients have advanced HIV disease and are unaware of their HIV status. These results reflect inadequate education of HIV risks and voluntary HIV testing in Thailand.

Coverage to curb the emerging HIV epidemic among injecting drug users in Pakistan: delivering prevention services where most needed

BACKGROUND

HIV Surveillance data from IDUs is suggestive of an escalating epidemic in major cities of Pakistan. The relatively widespread presence and interlinking of IDU and high-risk sexual networks, combined with low levels of HIV knowledge and prevention methods, indicate that there is potential for a rapid spread of HIV to other high-risk groups and its further expansion to general population through bridging groups.

METHODS

We reviewed Second Generation Surveillance data which provides mapping, biological and behavioural information from IDUs in eight major cities across Pakistan. Geographic mapping provided information about the location and size of the population, which was followed by a behavioural survey, conducted with a representative sample of 2432 IDUs. In addition, blood samples were also obtained which were tested for HIV.

RESULTS

Despite availability of syringe and needle exchange programmes in larger cities, drug users continued to reuse syringes (78.1%), injected in groups (73.3%) where extensive sharing of needle and injecting paraphernalia took place (50%). 12.6% of the respondents reported to having sexual relationships with female sex workers and 14.7% had sex with males in the past 6 months. 65% never used condoms. In addition 5.3% reported exchange of sex for money and drugs. Fairly low levels of coverage were reported from most of the cities.

CONCLUSION

Despite an existing nationwide harm reduction programme, increasing rates of HIV infection among IDUs underscore the need to identify gaps in the existing prevention strategy. Data available on coverage shows that effective harm reduction activities are unable to reach a substantial number of IDUs to actually avert or delay the emerging IDUs epidemic. There is an urgent need to expand coverage, and to integrate harm reduction in the mainstream of public health.

HIV drug resistance transmission threshold survey in Bangkok, Thailand

Background

Antiretroviral therapy (ART) began in Thailand in the Bangkok Metropolitan Area (BMA) in 1988 and scale-up began in 2001. The national first-line regimen is stavudine, lamivudine and nevirapine in fixed-dose combination, which is a regimen with a low genetic barrier for resistance. Because viral load and resistance testing are not widely available, unidentified HIV drug resistance (HIVDR) may occur during treatment and could be transmitted.

Methods

We undertook a threshold survey to assess HIVDR transmission in two subsets of recently infected individuals in the BMA. The first group consisted of returning blood donors tested at the Thai Red Cross National Blood Centre who seroconverted within the past 12 months. The second group comprised recently infected (as defined by BED assay) clients of the Thai Red Cross voluntary counselling and testing centre (VCT).

Results

Genotyping of 50 consecutive specimens each from blood donors and VCT clients during 2005–2006 showed no mutations associated with HIVDR in the reverse transcriptase or protease regions of the HIV pol gene. These results are categorized by the WHO HIV drug resistance threshold survey method as representing a low prevalence (<5%) of transmitted HIV drug resistance.

Conclusions

Every effort should be made to minimize the emergence of resistance in treated individuals and to prevent primary and secondary HIV transmission. To continue to monitor HIVDR transmission, Thailand has planned additional surveys – including longitudinal surveys – in these and additional groups of individuals.

The Thai HIV/AIDS epidemic at 15 years: sustained needle sharing among southern Thai drug injectors

To explore perceptions and attitudes towards needle sharing among clinic-based injecting drug abusers (IDUs) at a drug-treatment clinic in Hat Yai City, Songkla Province, Southern Thailand. Qualitative methods were used to gather data, including: in-depth interviews with 17 active IDUs and with three nurses, participant observation, review of the IDUs' files, and validation after interview completion to ensure data triangulation. A form of comparative content analysis, including thematic analysis, was used for data analysis. After 15 years of the Thai HIV/AIDS epidemic, most southern Thai IDUs still occasionally engaged in needle sharing although they reported reductions in sharing frequency. Withdrawal symptoms and craving were most commonly cited as compelling reasons to share. Misconceptions about how to determine "healthy" from the "sick" was another key factor underlying sharing. Pooling money for drugs (with subsequent cost-savings) was given priority over purchasing new needles/syringes among disadvantaged IDUs. Receiving HIV voluntary counseling and testing (VCT), however, promotes reduced sharing. Our findings suggest that southern Thai IDUs remain at high risk of acquiring HIV infection, primarily through needle sharing. Harm reduction strategies, such as, providing VCT to all IDUs and promoting needle exchange programs might be beneficial approaches to curbing the rapid spread of HIV.

Risk of syphilis in STI clinic patients: a cross-sectional study of 11,500 cases in Guangxi, China

OBJECTIVE

To measure prevalence of syphilis among the STI clinic population in Guangxi, China, and to assess the socioeconomic and behavioural characteristics associated with the infection.

METHODS

We undertook a cross-sectional survey and syphilis and HIV serologic testing among 11 473 patients attending 14 community and hospital-based dermatovenereal clinics across eight cities in Guangxi between December 2004 and February 2006.

RESULTS

1297 (11.9%) patients demonstrated positive toludine red unheated serum test and Treponema pallidum particle agglutination results with serologic testing. A total of 58% (752) of seropositive subjects presented with a genital ulcer, palmar/plantar rash or inguinal lymphadenopathy. Female sex (OR = 2.23, 95% confidence intervals (CI) = 1.69 to 3.00, p<0.001), less education (middle school, OR = 1.70, 95% CI = 1.11 to 2.62, p = 0.023; primary school or less, OR = 1.98, 95% CI = 1.13 to 3.46, p = 0.017) and high annual income (OR = 1.91, 95% CI = 1.18 to 3.10, p = 0.009 for >30 000 RMB yuan) were associated with serologically positive status. Syphilis infection was significantly more prevalent in city 2 (19.5%, OR = 3.07, 95% CI = 1.83 to 5.16, p<0.001), city 4 (16.6%, OR = 1.90, 95% CI = 1.10 to 3.28, p = 0.011) and city 8 (13.8%, OR = 1.83, 95% CI = 1.13 to 2.97, p = 0.006). A total of 40.1% (532) of infected subjects engaged in commercial sex and increased rates of the infection was associated with multiple sexual partners (OR = 1.54, 95% CI = 1.16 to 2.06, p = 0.003). A total of 1.2% (133) of participants carried laboratory markers for HIV and 1.8% (23) of patients with syphilis were positive for HIV.

CONCLUSIONS

Syphilis infection has reached alarming rates in China's STI clinic population, suggesting a generalised spread of the disease through commercial sex and bridging populations. Syphilis control is deserving of China's highest priority. Universal screening for syphilis and HIV testing in STI clinics should be considered as measures for control.

Complete genomes for hepatitis C virus subtypes 6f, 6i, 6j and 6m: viral genetic diversity among Thai blood donors and infected spouses

In this study, the first complete genome sequences for hepatitis C virus (HCV) subtypes 6f, 6i, 6j and 6m, obtained from infected blood donors in Chiang Mai, Thailand, are reported. Pairwise genome-wide nucleotide similarities between some of these isolates were higher than the 75-80% value used previously to define different HCV subtypes. To investigate further, the entire genomes of four prototype isolates, Th602 (6i), Th553 (6j), B4/92 (6m) and D86/93 (6n), were sequenced. Pairwise comparison of these sequences gave a similar range of nucleotide similarities, thereby providing new information for HCV subtype classification. In order to study the hypothesis of interspousal HCV transmission, four additional complete HCV genome sequences were obtained from two infected Thai blood donors and their spouses, C-0044 and C-0046 (6f), and C-0192 and C-0185 (6m). Pairwise comparison of the sequences revealed that C-0044 and C-0046 share a nucleotide similarity of 98.1%, whilst C-0185 and C-0192 have a similarity of 97.8%. Several other studies of partial HCV sequences of different genomic regions from HCV-infected couples have shown nucleotide similarities ranging from 96.3 to 100%. The similarities of the complete genome sequences from the two couples in the current study are consistent with HCV transmission between spouses.

Unequal evolutionary rates in the human immunodeficiency virus type 1 (HIV-1) pandemic: the evolutionary rate of HIV-1 slows down when the epidemic rate increases

HIV-1 sequences in intravenous drug user (IDU) networks are highly homogenous even after several years, while this is not observed in most sexual epidemics. To address this disparity, we examined the human immunodeficiency virus type 1 (HIV-1) evolutionary rate on the population level for IDU and heterosexual transmissions. All available HIV-1 env V3 sequences from IDU outbreaks and heterosexual epidemics with known sampling dates were collected from the Los Alamos HIV sequence database. Evolutionary rates were calculated using phylogenetic trees with a t test root optimization of dated samples. The evolutionary rate of HIV-1 subtype A1 was found to be 8.4 times lower in fast spread among IDUs in the former Soviet Union (FSU) than in slow spread among heterosexual individuals in Africa. Mixed epidemics (IDU and heterosexual) showed intermediate evolutionary rates, indicating a combination of fast- and slow-spread patterns. Hence, if transmissions occur repeatedly during the initial stage of host infection, before selective pressures of the immune system have much impact, the rate of HIV-1 evolution on the population level will decrease. Conversely, in slow spread, where HIV-1 evolves under the pressure of the immune system before a donor infects a recipient, the virus evolution at the population level will increase. Epidemiological modeling confirmed that the evolutionary rate of HIV-1 depends on the rate of spread and predicted that the HIV-1 evolutionary rate in a fast-spreading epidemic, e.g., for IDUs in the FSU, will increase as the population becomes saturated with infections and the virus starts to spread to other risk groups.

The importance of militaries from developing countries in global infectious disease surveillance

Military forces from developing countries have become increasingly important as facilitators of their government's foreign policy, taking part in peacekeeping operations, military exercises and humanitarian relief missions. Deployment of these forces presents both challenges and opportunities for infectious disease surveillance and control. Troop movements may cause or extend epidemics by introducing novel agents to susceptible populations. Conversely, military units with disease surveillance and response capabilities can extend those capabilities to civilian populations not served by civilian public health programmes, such as those in remote or post-disaster settings. In Peru and Thailand, military health organizations in partnership with the military of the United States use their laboratory, epidemiological, communications and logistical resources to support civilian ministry of health efforts. As their role in international affairs expands, surveillance capabilities of militaries from developing countries should be enhanced, perhaps through partnerships with militaries from high-income countries. Military-to-military and military-to-civilian partnerships, with the support of national and international civilian health organizations, could also greatly strengthen global infectious disease surveillance, particularly in remote and post-disaster areas where military forces are present.

Inconsistent condom use with steady and casual partners and associated factors among sexually-active men who have sex with men in Bangkok, Thailand

HIV/STD risk behavior has not been examined in community samples of men who have sex with men (MSM) in Thailand. The sexually-active sample (n=927) was recruited from bars, saunas, and parks; 20% identified as bisexual and 17% tested HIV-positive. Inconsistent (<100%) condom use was reported by 45% of those with steady partners and 21% of those with casual partners in the prior three months. 21% had heard of effective HIV treatments (n=194), among whom 44% believed HIV was less serious and 36% said their risk behavior had increased after hearing about the treatments. In multivariate analysis, HIV-positive status, gay-identification, getting most HIV information from the radio, believing HIV can be transmitted by mosquito bite, and concern about acquiring an STD were associated with inconsistent condom use during anal sex; slightly older age (25-29 vs. 18-24 years) was associated with more consistent condom use. HIV/STD risk-reduction strategies for MSM in Bangkok should clearly state sexual risk to individuals in this population.

Background demographics and risk behaviors of injecting drug users in Karachi, Pakistan

OBJECTIVE

To find the prevalence of HIV infection and risk behaviors among injecting drug users (IDUs) in Karachi, Pakistan.

DESIGN

A cross-sectional study of IDUs conducted in Karachi, Pakistan from February through June 1996.

RESULTS

Of the 242 IDUs, 11 (4%) refused HIV testing. One (0.4%; 95% confidence interval (CI) = 0.37-0.48%) was HIV positive. All subjects were male. Over the past 6 months 47% had engaged in receptive needle sharing, 38% had perceived a change in their social network, 22% had had sexual intercourse, of whom only 7% always used condoms, and none had washed their needles with bleach. Younger age (28 vs. 31 years; p = 0.01), younger age at first injection (25 vs. 28 years; p = 0.001), fewer years of schooling (3 vs. 5 years; p = 0.001), lower monthly income (70 dollars vs. 80 dollars; p = 0.03), inhaling fumes of heroin from a foil in the year before injecting (OR = 4.8; CI = 2.2-10.3), injecting first time with heroin (OR = 3.6; CI = 1.2-12.6), having a temporary job (OR = 2.5; CI = 1.2-5.2), and a perceived change in one's social network (OR = 4.4; CI = 2.4-7.9) were all associated with receptive needle sharing. IDUs who knew about HIV spread through contaminated needles were less likely to share (OR = 0.4; CI 0.2-0.8). In the final logistic regression model receptive needle sharing was associated with inhaling of fumes of heroin on a foil in the year prior to injecting (adjusted OR = 5.6; CI = 2.6-12.0), a perceived change in one's social network (adjusted OR = 4.0; CI = 2.2-7.4), and inversely associated with age at first time of injection (beta = -0.07; p = 0.002).

CONCLUSION

Background HIV prevalence was low among IDUs in Karachi despite high-risk behavior in 1996. In order to control HIV transmission among IDUs in Pakistan, continual HIV surveillance with well-coordinated and effective HIV risk reduction, and drug demand reduction programs need to be implemented among drug users.

High risk populations and HIV-1 infection in China

China is currently experiencing one of the most rapidly expanding HIV epidemics in the world. Although the overall prevalence rate is still low, with a population of 1.3 billion, high-risk factors which have contributed to the HIV/AIDS epidemics worldwide continue to prevail in China, including a high rate of injecting drug use and needle sharing, commercial sex with low rates of condom use, and concurrent sex with both commercial sex workers and non-commercial casual or steady sex partners. In addition, there are increasing "double risk" populations overlapping drug users and sex workers, as well as increasing rates of STDs and HIV among high-risk populations. Sexual transmission, therefore, may serve as a bridge connecting high-risk populations with general populations. There is an urgent need to prevent the spread of HIV from these high-risk populations into the general population of China.

Correlates and Trend of HIV Prevalence Among Female Sex Workers Attending Sexually Transmitted Disease Clinics in Pune, India (1993-2002)

In India, substantial efforts have been made to increase awareness about HIV/AIDS among female sex workers (FSWs). We assessed the impact of awareness regarding safe sex in a cohort of FSWs by studying trends in HIV prevalence, sexually transmitted diseases (STDs), and risk behaviors measured from 1993 to 2002 in Pune, India. A total of 1359 FSWs attending 3 STD clinics were screened for HIV infection, and data on demographics, sexual behaviors, and past and current STDs were obtained. The overall HIV prevalence among FSWs was 54%. Not being married (adjusted odds ratio [AOR] = 1.74, 95% confidence interval [CI]: 1.17 to 2.59), being widowed (AOR = 2.10, 95% CI: 1.16 to 3.80), inconsistent condom use (AOR = 1.60, 95% CI: 1.02 to 2.50), clinical presence of genital ulcer disease (GUD; AOR = 1.66, 95% CI: 1.07 to 2.56), and genital warts (AOR = 4.70, 95% CI: 1.57 to 14.08) were independently associated with HIV infection among FSWs. The prevalence of HIV remained stable over 10 years (46% in 1993 and 50% in 2002; P = 0.80). The prevalence of GUD decreased over time (P < 0.001), whereas that of observed genital discharge remained stable. Reported consistent condom use as well as the proportion of FSWs who refused sexual contact without condoms increased over time (P < 0.001). These data collectively suggest that safe sex interventions have had a positive impact on FSWs in Pune, India.

AIDS: The Second Wave

Over two decades ago, the first cases of a new disease now known as AIDS were described in the literature. Since then, remarkable advances have been made, a new retrovirus has been discovered, promising antiviral agents have been developed and affordable and effective preventive interventions exists. Yet the AIDS pandemic continues largely unabated. AIDS is the world's leading infectious disease cause of death and threatens to devastate the economic systems of resource-poor nations. Over the next decade the HIV epidemic is expected to continue to grow with an increasing proportion of infected persons residing in developing countries and increasingly affecting young women. However, reducing the burden of HIV/AIDS is achievable, and there is some cause for cautious optimism.

Factors associated with condom use among brothel-based female sex workers in Thailand

This study sought to determine the actual levels of condom use by female sex workers (FSW) in Thailand brothels. Specifically, it examined the influence that the country of origin of the FSW patrons exerted on usage of a condom, and it assessed the relevancy of constructs from the Health Belief Model in predicting FSW requesting condom usage by their clients. A survey was administered to a cross-sectional non-randomized convenience sample of 150 FSW in four geographic locations in Thailand, which included: Bangkok, Chang Mai, Mae Hong Son and Other (comprised mainly of brothels in small villages). Statistical interpretation of the data indicated that Thai FSW requested condom use in 63% of the cases, while the overall mean of condom use was only 51%. Condom use by patrons' country of origin was as follows: westerners 76%, foreign Asians 52% and native Thai men 27%. These results fall considerably short of the Ministry of Health's goal of 100% condom use in Thai brothels. Furthermore, public health education initiatives need to effectively target the native Thai FSW patrons since they represent the clients least likely to use a condom (27%).

The natural history of HIV-1 infection in young Thai men after seroconversion

The natural history and progression of HIV-1 infection in Thailand and other developing countries in Asia and Africa have not been well defined. Nevertheless, valid data are needed to evaluate the effects of interventions, which are designed to delay progression. We evaluated the progression to AIDS and death in 235 men who seroconverted during their 2 years of service in the Royal Thai Army. The men were conscripted at age 21 and seroconverted within a 6-month window during follow-up while in the military. The seroconverters were matched with men who were seronegative when discharged. Of the HIV-positive men, 156 (66.4%) were alive, 77 (32.8%) had died, and 2 (0.8%) could not be located 5-7 years after their seroconversion and discharge from the military. The 5-year survival rate was 82.3%; the median times to clinical AIDS and a CD4 cell count of <200/microL was 7.4 years and 6.9 years, respectively. The mortality rate was 56.3 deaths per 1000 patient-years for HIV-positive men and 6.1 deaths per 1000 patient-years for HIV-negative men. Our data suggest a more rapid progression to AIDS and death after HIV-1 infection in young men in Thailand than has been reported for similarly aged cohorts in developed countries.

Heterosexual transmission of novel CRF01_AE and subtype B recombinant forms of HIV type 1 in northern Thailand

The increased proportion of CRFO1_AE/subtype B recombinant infections among injecting drug users raised a concern that such recombinant forms may also spread in a heterosexual population in Thailand. Using the BootScan method, we reanalyzed pol gene sequences among 114 heterosexually infected individuals in northern Thailand, who were tested for a drug-resistance genotype between July 2000 and July 2001. Two individuals were suspected of carrying a recombinant HIV-1. Thus we analyzed a nearly full-length HIV genome in the two individuals and their spouses. An identical recombinant form of CRF01_AE and subtype B was found in one couple, indicating that this recombinant virus was heterosexually transmitted. Interestingly, this recombinant form had multiple breakpoints in the core protein of Gag and both infected individuals had a high CD4+ cell count without antiretroviral therapy. CRFO1/subtype B recombinant forms exist in a heterosexual population in northern Thailand. Some recombinant virus may be associated with a slow rate of HIV disease progression.

Risk of HIV Transmission Within Marriage in Rural China: Implications for HIV Prevention at the Family Level

BACKGROUND

Little is known about HIV transmission at the family level in China.

GOAL

: We examined the risks for HIV transmission between husbands and wives and from parents to children in a rural area where HIV spread among former commercial blood donors.

STUDY

A cross-sectional study was conducted among 605 (302 couples) marriage license applicants.

RESULTS

More males (64.6%) than females (52.1%) reported having had premarital sex and multiple sex partners (12.6% and 6.9%, respectively). Among those having had multiple sex partners, 8.5% reported often or always using condoms. Only 36.8% of the couples agreed that they would not plan to have a baby after knowing the status of HIV infection. Approximately 43% of the couples agreed that they would use condoms consistently if 1 of them were HIV-positive.

CONCLUSIONS

There is an urgent need for national programs to prevent HIV infection within couples in rural areas.

Herbal medicine use and quality of life among people living with HIV/AIDS in northeastern Thailand

Many people living with HIV/AIDS (PHA) use herbal medicine as one of alternative therapies, where curative options are limited. This study aimed to examine the association between the herbal medicine use and quality of life (QOL) among PHA in northeastern Thailand. Participants were 132 HIV-positive Thai adults who attended the PHA's self-help group meetings from June to July 2002. Health-related QOL scores were measured by self-administered questionnaire from the Medical Outcomes Study-HIV Health Survey. Dimensions of physical function (PF) and mental health (MH) in QOL were assessed. Additional data were collected on herbal medicine use, socio-demographic, psychosocial and HIV-related characteristics. The herbal medicine users had significantly better MH scores than the non-users, while the herbal medicine use was not statistically associated with PF scores. When stratified, herbal medicine users with the following characteristics had significantly better MH scores than the non-users: female, widowed, having no income, reporting any HIV-related symptom, having no instrumental support or receiving subsidies. In conclusion, herbal medicine use was associated with better MH especially among socially vulnerable PHA. This study suggests that herbal medicine has a potential to improve the MH aspect of QOL among socially vulnerable PHA who cannot easily receive antiretroviral therapy in Thailand.

HIV infection among female drug users in Northern Thailand

Reports on HIV infection and risk behaviors among female drug users in developing countries, particularly in Asia, are limited. In this study, we investigated HIV prevalence and risk factors for HIV infection among 200 women admitted for 21-day inpatient drug detoxification in Chiang Mai, Thailand. Volunteers completed a face-to-face interview using a structured interview, HIV pre-test counseling, specimen collection for HIV and STD tests, and were provided test results and HIV post-test counseling 1 week later. Two-third of participants (68%) were ethnic minorities with no formal education. Overall, 14 (7%) were HIV positive: 25% among 28 heroin injectors and 4.1% among 172 opium or methamphetamine smokers (p<0.001). History of drug injection and sexual abuse were associated with HIV infection. HIV prevention strategies for drug-using women in Thailand should consider both harm reduction strategies for drug use and promoting safer sex measures in a culturally appropriate context.

Heterosexual Transmission of HIV in China: A Systematic Review of Behavioral Studies in the Past Two Decades

OBJECTIVE

The objective of this study was to address the role of heterosexual transmission of HIV in China.

GOAL

The goal of this study was to explore the prevalence of unsafe sex and the likelihood of HIV spread heterosexually from core populations to others.

STUDY

The authors conducted a review of behavioral studies.

RESULTS

Drug users were more likely to be involved in higher-risk sexual behaviors than were those who abstained from using drugs. Most female drug users (52-98%) reported having engaged in commercial sex. Most female sex workers (FSWs) and individuals with sexually transmitted diseases (STDs) had concurrent sexual partners. Many continued to have unprotected sex after noticing STD symptoms in themselves or their sexual partners. From 5% to 26% of rural-to-urban migrants had multiple sexual partners and 10% of males patronized FSWs during migration.

CONCLUSIONS

Factors such as high rates of FSW patronage, low rates of condom use during commercial sex, having sex with both commercial and noncommercial sexual partners, and high rates of STD infection may promote a heterosexual epidemic in China.

Evidence of a previously undocumented epidemic of HIV infection among men who have sex with men in Bangkok, Thailand

BACKGROUND

The HIV prevalence and associated risk behaviours in Thai men who have sex with men (MSM) are unknown. This information is crucial to inform and implement targeted preventive interventions for this population.

METHODS

A cross-sectional assessment, using venue-day-time sampling, was conducted. Participants were 1121 Thai men who were 18 years or older, were residents of Bangkok, and reported anal or oral sex with a man during the past 6 months. Oral fluid specimens were tested for HIV antibody. Demographic and behavioural data were collected using an interviewer-administered Palm based automated questionnaire.

RESULTS

HIV prevalence was 17.3% (194 of 1121). Mean age was 26.9 years (median 25 years), and university education was completed by 42.5%. Sex with men and women during the past 6 months was reported by 22.3%; sex with a woman ever, 36%; and unprotected sexual intercourse during the past 3 months, 36.0%. Alcohol use during the past 3 months was common (73.7%); drug use was rare (2.5%). Multivariate logistic regression analyses showed lower education, recruitment from a park, self-identification as homosexual, receptive and insertive anal intercourse, more years since first anal intercourse, and more male sex partners to be significantly and independently associated with HIV prevalence.

CONCLUSIONS

HIV infection is common among MSM in Bangkok. HIV prevention programs are urgently needed to prevent further spread of HIV in this young and sexually active population.

Factors associated with HIV testing, condom use, and sexually transmitted infections among female sex workers in Nha Trang, Vietnam

This study examined predictors of HIV testing, successful condom negotiation with clients, and self-reported sexually transmitted infections (STIs) among Vietnamese female sex workers (FSW). Data were collected by using face-to-face interviews from a community sample of 610 FSW from Nha Trang city during October-December, 2000. Having had an HIV test was associated with having spent time in a rehabilitation center. Consistently successful negotiation of condom use occurred most among FSW who had few clients, understood how HIV was not transmitted, and had not reported ever having any symptoms of STIs. Migration to Nha Trang for sex work was a risk factor for an STI diagnosis; successful negotiation of condom use had a protective effect. Our results suggest the need for voluntary HIV counseling and testing, further promotion of condom use among FSW populations, and better use of rehabilitation sites to promote HIV prevention.

HIV-1 subtype E progression among northern Thai couples: traditional and non-traditional predictors of survival

BACKGROUND

In the continuing effort to introduce antiretroviral therapy in resource-limited settings, there is a need to understand differences between natural history of HIV in different populations and to identify feasible clinical measures predictive of survival.

METHODS

We examined predictors of survival among 836 heterosexuals who were infected with HIV subtype CRF01_AE in Thailand.

RESULTS

From 1993 to 1999, 269 (49.4%) men and 65 (25.7%) women died. The median time from the estimated seroconversion to death was 7.8 years (95% confidence interval 7.0-9.1). Men and women with enrolment CD4 counts <200 cells/microl had about 2 and 11 times greater risk of death than those with CD4 counts of 200-500 and >500, respectively. Measurements available in resource-limited settings, including total lymphocyte count (TLC), anaemia, and low body mass index (BMI), also predicted survival. Men with two or more of these predictors had a median survival of 0.8 (0.5-1.8) years, compared with 2.7 (1.9-3.3) years for one predictor and 4.9 (4.1-5.2) years for no predictors.

CONCLUSIONS

The time from HIV infection to death appears shorter among this Thai population than among antiretroviral naive Western populations. CD4 count and viral load (VL) were strong, independent predictors of survival. When CD4 count and VL are unavailable, individuals at high risk for shortened HIV survival may be identified by a combination of low TLC, anaemia, and low BMI. This combination of accessible clinical measures of the disease stage may be useful for medical management in resource-limited settings.

HIV-related risk factors associated with commercial sex among female migrants in China

Data from 633 sexually experienced female migrants were analyzed to examine the sociodemographic and psychosocial factors and human immunodeficiency virus (HIV)-related behaviors associated with involvement in commercial sex. Six percent (40/633) of the participants reported having had sex for money. Compared with women who had not engaged in commercial sex, women who had sold sex were younger, less educated, and more likely to be unmarried. They were more likely to have engaged in HIV-related risk behaviors, such as becoming intoxicated with alcohol and using drugs. Among women engaged in commercial sex, only 28% of them consistently used condoms during the last three episodes of sexual intercourse. Women who had ever engaged in commercial sex demonstrated greater depressive symptoms than those without such as history (p < .01). Female migrants, especially those engaging in commercial sex, were vulnerable to HIV/sexually transmitted diseases (STDs). Sexual risk reduction and condom promotion are urgently needed among this population. Further studies are needed to examine the casual relationship between depression and HIV risk behaviors.

Insights into the role of host genetic and T-cell factors in resistance to HIV transmission from studies of highly HIV-exposed Thais

Studies of resistance to HIV-1 transmission are likely to be valuable for the design of vaccines and other efforts to prevent HIV. Here, we review the T-cell and genetic factors associated with resistance to HIV-1 transmission in studies of highly exposed but persistently seronegative (HEPS) women from northern Thailand. Women were enrolled in two sex-worker studies and in a discordant couple study. We performed Cr51 cytotoxic T lymphocyte (CTL), interferon-gamma (IFN-gamma) ELISPOT, and proliferation assays as well as genetic studies, including HLA-class I typing. CTL and ELISPOT studies showed a skewing of T-cell responses to conserved HIV-1 proteins in HEPS, but not in HIV-1-seropositive women. T-cell responses were extremely long-lived in some HEPS women. In the two sex-worker studies, HLA-A11 was associated with resistance to HIV-1 transmission. These data provide promise for the ability of CTL to control HIV and emphasize the importance of developing HIV vaccines that stimulate strong, long-lasting Tcell responses.

Frequent Human Leukocyte Antigen Class I Alleles Are Associated With Higher Viral Load Among HIV Type 1 Seroconverters in Thailand

The loss of viral control by the host may be due to the evolution of viruses with mutations that limit presentation by human leukocyte antigen (HLA) to cytotoxic T cells. The authors hypothesized that the consequence of such evolution might be that persons with common HLA class I alleles would be less able to control viremia, on average, than would those with rare alleles. HLA class I typing was completed for 128 injection drug users who seroconverted in a prospective cohort study in Bangkok, Thailand. Logistic regression was used to model viral load (greater than or equal to the median) at 9 and 12 months after seroconversion with an HLA score that profiled the relative prevalence of each individual's alleles. At 12 months after seroconversion, injection drug users with the most common HLA alleles (highest quartile HLA score) had an almost 4-fold increased risk for higher viral load (> or = 32,055 copies/mL) than injection drug users with less common HLA alleles (adjusted odds ratio, 3.92; 95% confidence interval, 1.3-11.8). These findings support the importance of frequency-dependent effects of host genes on HIV type 1 evolution in different populations and suggest that HLA-driven viral evolution critically influences control of viremia in early HIV type 1 infection.

HIV/AIDS in Asia

HIV (ie, HIV-1) epidemics in Asia show great diversity, both in severity and timing. But epidemics in Asia are far from over and several countries including China, Indonesia, and Vietnam have growing epidemics. Several factors affect the rate and magnitude of growth of HIV prevalence, but two of the most important are the size of the sex worker population and the frequency with which commercial sex occurs. In view of the present state of knowledge, even countries with low prevalence of infection might still have epidemics affecting a small percentage of the population. Once HIV infection has become established, growing needs for care and treatment are unavoidable and even the so-called prevention-successful countries of Thailand and Cambodia are seeing burgeoning care needs. The manifestations of HIV disease in the region are discussed with the aim of identifying key issues in medical management and care of HIV/AIDS. In particular, issues relevant to developing appropriate highly active antiretroviral treatment programmes in the region are discussed. Although access to antiretroviral therapy is increasing globally, making it work effectively while simultaneously expanding prevention programmes to stem the flow of new infections remains a real challenge in Asia. Genuine political interest and commitment are essential foundations for success, demanding advocacy at all levels to drive policy, mobilise sufficient resources, and take effective action.

CCR5 promoter human haplogroups associated with HIV-1 disease progression in Thai injection drug users

BACKGROUND

An evolutionary-based analysis of the CC chemokine receptor 5 gene (CCR5) promoter region has identified nine stable human haplogroups, within which certain haplogroups appear to influence HIV-1 disease progression differentially among Caucasians and African-Americans.

OBJECTIVE

To assess the influence of CCR5 haplogroups on HIV-1 disease progression in a Thai population.

DESIGN

Haplogroup analysis of HIV-1-seropositive injection drug users (IDU) participating in a prospective cohort study in Bangkok. All were documented seroconverters with a median follow-up time of 3.5 years (range, 0.2-7.0).

METHODS

From a cohort of 130 IDU, 106 (81.5%) were genotyped for the CCR2b-64I, CCR5-delta32 and seven CCR5 promoter alleles constituting the CCR5 haplogroups. Survival curves and adjusted Cox proportional hazards models were used to assess the effect of haplogroups on the time from HIV-1 infection until CD4 count < 200 x 10(6) cells/l.

RESULTS

The most common CCR5 haplogroups were HHC (61.8%), followed by HHE (15.6%) and HHF*2 (14.6%). HHE was associated with an accelerated CD4 count decline to < 200 x 10(6) cells/l (adjusted relative hazard, 1.88; 95% confidence interval, 1.05-3.36; P = 0.02).

CONCLUSIONS

This is the first evidence that the CCR5 haplogroup E speeds the decline of the CD4 cell count and may lead to accelerated disease progression among HIV-infected Thais. These new observations highlight the need for additional studies involving populations in Asia.