The epidemiology of HIV infection and AIDS in Thailand

The AIDS Epidemic Model 2023 for Estimating HIV Trends and Transmission Dynamics in Asian Epidemic Settings

BACKGROUND

Thirteen Asian countries use the AIDS Epidemic Model (AEM) as their HIV model of choice. This article describes AEM, its inputs, and its application to national modeling.

SETTING

AEM is an incidence tool used by Spectrum for the Joint United Nations Programme on HIV/AIDS global estimates process.

METHODS

AEM simulates transmission of HIV among key populations (KPs) using measured trends in risk behaviors. The inputs, structure and calculations, interface, and outputs of AEM are described. The AEM process includes (1) collating and synthesizing data on KP risk behaviors, epidemiology, and size to produce model input trends; (2) calibrating the model to observed HIV prevalence; (3) extracting outputs by KP to describe epidemic dynamics and assist in improving responses; and (4) importing AEM incidence into Spectrum for global estimates. Recent changes to better align AEM mortality with Spectrum and add preexposure prophylaxis are described.

RESULTS

The application of AEM in Thailand is presented, describing the outputs and uses in-country. AEM replicated observed epidemiological trends when given observed behavioral inputs. The strengths and limitations of AEM are presented and used to inform thoughts on future directions for global models.

CONCLUSIONS

AEM captures regional HIV epidemiology well and continues to evolve to meet country and global process needs. The addition of time-varying mortality and progression parameters has improved the alignment of the key population compartmental model of AEM with the age-sex-structured national model of Spectrum. Many of the features of AEM, including tracking the sources of infections over time, should be incorporated in future global efforts to build more generalizable models to guide policy and programs.

The Emerging of CRF01_AE: A Clinical Story and Future HIV/AIDS Situation in Thailand

The HIV epidemic in Thailand in the 1980's compromised the country's socio-economic development. The epidemic first became evident in the community of men with male sexual partners (MSM), and subsequently spread to intravenous drug users (IVDU), female commercial sex workers (CSW) and their male clients, and, ultimately, to their partners and children. The HIV epidemic has devastated the country's working-age population. The extensive negative impact and social stigma associated with the disease do not only have an impact on the victims of HIV but also on their descendants and relatives. An epicenter of the HIV epidemic has been in the northern provinces of Thailand. An HIV-1 subtype CRF01_AE, a complex chimeric virus composed of both A and E subtypes, is prevalent in Northern Thailand. The virus has quickly become a predominant viral strain circulating in Thailand, other neighboring Southeast Asian countries, and China as well as some other countries throughout the world. The epidemiology, evolution, and biology of CRF01_AE offer a unique model for further scientific investigations which would advance the knowledge of and curative strategies against HIV. In addition, Thailand has developed suitable national guidelines on HIV/AIDS treatment and prevention in order to control the epidemic. Effective antiretroviral drugs are, therefore, able to be made available to those who live with HIV. The national surveillance system has also been effective. The great efforts and resources which Thailand has dedicated to the fight against the epidemic have eventually paid off. In 2010, a plan was proposed to eliminate mother-to-child HIV transmission and Thailand has become the first country to be effective in this objective. Thailand therefore has become recognized as being the global leader in HIV prevention and treatment. The experience which Thailand has gained from the past and the current research and management strategies of the HIV epidemic has prepared the country for emerging strains of HIV-1 in the future.

Prevalence of HIV infection and related risk factors among young Thai men between 2010 and 2011

Introduction

Understanding the current epidemiology of human immunodeficiency virus (HIV) infection in Thailand will facilitate more effective national HIV prevention programs. This study aimed to determine the prevalence and risk factors for HIV infection among young Thai men.

Methods

A total survey was conducted of Royal Thai Army new conscripts, participating in the national HIV surveillance in November 2010 and May 2011. Behavioral risk factors for HIV infection were determined using a standardized survey questionnaire in the total study population and men who have sex with men (MSM) subgroup.

Results

A total of 301 (0.5%) HIV infected young Thai men were identified from the total study population (63,667). Independent risk factors associated with HIV infection among the total study population included being single (adjusted Odds Ratio [AOR] 1.6, 95% Confidence Interval [CI] 1.1–2.2), having no formal education (AOR 6.5, 95% CI 2.3–18.4) or a bachelor’s degree (AOR 1. 8, 95% CI 1.0–3.0), engaging in bisexual (AOR 3.7, 95% CI 2.4–5. 6) or exclusively homosexual activity (AOR 14.4, 95% CI 10.4–19.8), having a history of Sexually Transmitted Infection (STI) (AOR 2.3, 95% CI 1.6–3.3) and having sex in exchange for gifts/money (AOR 2.0, 95% CI 1. 5–2.8). A total of 4,594 (7.9%) MSM were identified, of which 121 (2.6%) were HIV infected. The prevalence of HIV infection among MSM in urban (2.8%) and rural (2.4%) areas were relatively comparable (p-value = 0.44). Of the identified MSM, 82.5% reported having sexual desire with females only. Risk factors associated with HIV infection in the MSM subgroup included living in the western region (AOR 3.5, 95% CI 1.2–10.4), having a bachelor’s degree (AOR 2.7, 95% CI 1.2–5.7), having a history of exclusive receptive (AOR 3.6, 95% CI 1.6–7.7) or versatile anal sex (AOR 4.7, 95% CI 3.0–7.5) and history of having sex in exchange for gifts/money (AOR 2.3, 95% CI 1.5–3.5).

Conclusion

The prevalence of HIV infection among young Thai men has continued to be below 0.5% in 2010 and 2011. High risk sexual activity, including MSM, played a major role in the HIV epidemic among this population. Effective HIV prevention programs should cover MSM who have heterosexual desire as well as having sex in exchange for gifts/money and be implemented in both urban and rural areas.

Evolving HIV epidemics: the urgent need to refocus on populations with risk

Purpose of review

To explore the comparative importance of HIV infections among key populations and their intimate partners as HIV epidemics evolve, and to review implications for guiding responses.

Recent findings

Even as concentrated epidemics evolve, new infections among current and former key population members and their intimate partners dominate new infections. Prevalent infections in the general population grow primarily because of key population turnover and infections among their intimate partners. In generalized epidemic settings, data and analysis on key populations are often inadequate to assess the impact of key population-focused responses, so they remain limited in coverage and under resourced. Models must incorporate downstream infections in comparing impacts of alternative responses.

Summary

Recognize that every epidemic is unique, moving beyond the overly simplistic concentrated/generalized epidemic paradigm that can misdirect resources. Guide HIV responses by gathering and using locally relevant data, understanding risk heterogeneity, and applying modeling at both national and sub-national levels to optimize resource allocations among different populations for greatest impact. Translate this improved understanding into clear, unequivocal advice for policymakers on where to focus for impact, breaking them free of the generalized/concentrated paradigm limiting their thinking and affecting their decisions.

Burden of communicable diseases and cost of illness: Asia pacific region

BACKGROUND

Communicable diseases such as AIDS/HIV, dengue fever, and malaria have a great burden and subsequent economic loss in the Asian region. The purpose of this article is to review the widespread burden of communicable diseases and related health-care burden for the patient in Asia and the Pacific.

AREAS COVERED

In Central Asia, the number of new AIDS cases increased by 29%. It is more endemic in the poor population with variations in the cost of illness. Dengue is prevalent in more than 100 countries, including the Asia-Pacific region. In Southeast Asia, the annual economic burden of dengue fever was between $ 610 and $ 1,384 million, with a per capita cost of $ 1.06 to $ 2.41. Globally, 2.9 billion people are at risk of developing malaria, 90% of whom are residents of the Asia and Pacific region. The annual per capita cost of malaria control ranged from $ 0.11 to $ 39.06 and for elimination from $ 0.18 to $ 27.

EXPERT OPINION

The cost of AIDS, dengue, and malaria varies from country to country due to different health-care systems. The literature review has shown that the cost of dengue disease and malaria is poorly documented.

Disclosure of HIV status among Shan female migrant workers living with HIV in Northern Thailand: A qualitative study

BACKGROUND

Disclosure of HIV status is a critical gateway to HIV prevention. Despite many studies on this topic, there is a gap in knowledge regarding HIV status disclosure and risky sexual behavior in HIV-infected female migrant workers. The current study addressed this research gap, and focused on HIV-infected Shan female migrant workers in Northern Thailand.

METHODS

This study conducted in-depth interviews with 18 HIV-infected Shan female migrants (aged between 23-54 years old) and 29 healthcare workers in district hospitals in Chiang Mai. Content analysis was employed to identify particular themes related to HIV status disclosure, sexual risk behavior, and ART adherence.

RESULTS

We found that non-disclosure to husbands/partners was mostly related to fear of marital conflict and of losing social and financial support. Non-disclosure prevented Shan female migrant workers from negotiating condom use with their partners. Reasons for not disclosing to friends, family and other community members were mostly related to feared rejection and discrimination due to HIV-related stigma. Accounts of condomless sex in the context of HIV status disclosure suggest that gender norms and male dominance over women influenced decision-making for safe sex. Lastly, some female migrant workers perceived low risk of HIV transmission with good adherence to the ART.

CONCLUSIONS

This study highlighted the complex challenges of HIV status disclosure among HIV-positive Shan female migrant workers and the link between disclosure/non-disclosure and condom use. There is a pressing need to create realistic disclosure mechanisms that take into account the socio-cultural barriers to disclosure including marital conflicts, stigma, and gender norms. Messages to encourage condom use should be delivered carefully so that knowledge of the HIV transmission reduction qualities of good ART adherence does not serve as a barrier to condom use.

HIV Incidence and Risk Behaviours of People Who Inject Drugs in Bangkok, 1995-2012

BACKGROUND

Three consecutive prospective studies were conducted among people who inject drugs (PWID) from May 1995 through June 2012 in Bangkok, Thailand. We examined data from these studies to evaluate HIV incidence and explore trends in risk behaviours.

METHODS

We used data from a 1995-1998 cohort study, a 1999-2004 HIV vaccine trial, and a 2005-2012 HIV pre-exposure prophylaxis (PrEP) study to examine per-quarter trends in HIV incidence, using a restricted cubic spline function for time in a Poisson regression. We also examined temporal trends in HIV-associated risk behaviours.

FINDINGS

HIV incidence declined from 5.7 per 100 person-years during the cohort study, to 2.7 per 100 person-years in the vaccine trial, to 0.7 per 100 person-years among PrEP study placebo recipients. Incidence peaked at 12.1 per 100 person-years in 1996 and declined to < 1 per 100 person-years during 2005-2012. Reports of injecting drugs and sharing needles also declined from the cohort study to the PrEP study (p < 0.0001). Heroin was the most common drug injected during the cohort study and the vaccine trial, but stimulants (e.g., methamphetamine) and sedatives (e.g., midazolam) were injected more often during the PrEP study.

INTERPRETATION

HIV incidence among PWID declined during 2005-2012. Several factors likely contributed to the decline, including decreases in the frequency of injecting and sharing, improved access to HIV testing and antiretroviral therapy, and the use of PrEP. Expanding access to effective HIV prevention tools can hasten control of the HIV epidemic among PWID.

FUNDING

The Bangkok Metropolitan Administration and U.S. Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention.

Molecular epidemiology of a primarily MSM acute HIV-1 cohort in Bangkok, Thailand and connections within networks of transmission in Asia

INTRODUCTION

Thailand plays a substantial role in global HIV-1 transmission of CRF01_AE. Worldwide, men who have sex with men (MSM) are at elevated risk for HIV-1 infection. Hence, understanding HIV-1 diversity in a primarily Thai MSM cohort with acute infection, and its connections to the broader HIV-1 transmission network in Asia is crucial for research and development of HIV-1 vaccines, treatment and cure.

METHODS

Subtypes and diversity of infecting viruses from individuals sampled from 2009 to 2015 within the RV254/SEARCH 010 cohort were assessed by multiregion hybridization assay (MHAbce), multiregion subtype-specific PCR assay (MSSPbce) and full-length single-genome sequencing (SGS). Phylogenetic analysis was performed by maximum likelihood. Pairwise genetic distances of envelope gp160 sequences obtained from the cohort and from Asia (Los Alamos National Laboratory HIV Database) were calculated to identify potential transmission networks.

RESULTS

MHAbce/MSSPbce results identified 81.6% CRF01_AE infecting strains in RV254. CRF01_AE/B recombinants and subtype B were found at 7.3% and 2.8% respectively. Western subtype B strains outnumbered Thai B' strains. Phylogenetic analysis revealed one C, one CRF01_AE/CRF02_AG recombinant and one CRF01_AE/B/C recombinant. Asian network analysis identified one hundred and twenty-three clusters, including five clusters of RV254 participants. None of the RV254 sequences clustered with non-RV254 sequences. The largest international cluster involved 15 CRF01_AE strains from China and Vietnam. The remaining clusters were mostly intracountry connections, of which 31.7% included Thai nodes and 43.1% included Chinese nodes.

CONCLUSION

While the majority of strains in Thailand are CRF01_AE and subtype B, emergence of unique recombinant forms (URFs) are found in a moderate fraction of new HIV-1 infections. Approaches to vaccine design and immunotherapeutics will need to monitor and consider the expanding proportion of recombinants and the increasing genetic diversity in the region. Identified HIV-1 transmission networks indicate ongoing spread of HIV-1 among MSM. As HIV-1 epidemics continue to expand in other Asian countries, transmission network analyses can inform strategies for prevention, intervention, treatment and cure.

Do HIV prevention interventions in Asia lead to increase in condom utilization?: A meta-analysis study

This meta-analytic review synthesizes the findings of published independent studies that assessed the effectiveness of HIV prevention interventions in promoting condom usage in Asia. We focused on 20 studies that used randomized control studies to establish whether HIV prevention interventions lead to increased condom utilization. As compared with the average control group client, we found that 68% of the clients who participated in an intervention group increased their condom usage. The effectiveness of HIV prevention intervention is not related to country and rural-urban contexts, to male-female samples, to the type of outcome measured, or the timing of the latest follow-up assessment. The implications of these findings are that policy-makers, health administrators, and international donors should view behavioral HIV prevention interventions as an effective approach through which to increase condom usage in order to reduce the HIV infection rate in Asia.

Socio-behavioral risk factors among older adults living with HIV in Thailand

BACKGROUND

There has been a global increase in HIV infection in persons 50 years of age and older. This group is at risk for development of chronic illness that may be exacerbated by socio-behavioral risk factors such as smoking, unhealthy alcohol use, and sedentary lifestyle. However, socio-behavioral risk factors in this older HIV infected population are not well described. The current study aims to describe and document factors related to alcohol use, tobacco smoking, and physical exercise in older adults living with HIV (OALHIV).

METHODS

This cross-sectional quantitative study was conducted between August and September 2015, and enrolled HIV-infected participants aged 50 years and older from 12 community hospitals in Chiang Mai Province, Northern Thailand.

RESULTS

Of the 364 participants recruited in the study, 57.1% were female, and 67.3% were between 50-59 years of age. Respectively, 15.1%, 59.1%, and 18.7% were current smokers, currently engaged in physical exercises, and reported ever drank alcohol in the past year. 22.1% of those who drank alcohol reported experience of heavy episodic drinking. Male gender was one of the strongest predictors of ever drank alcohol in the past year (AOR, 4.66; CI, 2.28-9.49; P<0.001) and of being a current smoker (AOR, 13.41; CI, 7.23-24.87; P<0.001). Lower household income was associated with increased odds of ever drank alcohol in the past year (household income (1 USD = 35 THB) of ≤ 5,000 Baht versus > 20,000 Baht: AOR, 5.34; CI, 1.28-22.25; P = 0.021). Lower educational level was associated with decreased odds of physical exercises (no education versus secondary and higher: AOR, 0.22; CI, 0.08-0.55; P = 0.001).

CONCLUSION

Smoking and alcohol use is common among OALHIV, with a substantial proportion not engaging in physical exercises. Interventions for OALHIV should particularly target males and those of lower socio-economic status to deter smoking and alcohol use and to promote physical exercises.

Burden of HIV, Syphilis, and Hepatitis B and C Among Inmates in a Prison State System in Mexico

We studied the prevalence of HIV, syphilis, hepatitis B virus (HBV), and hepatitis C virus (HCV) infection and associated risk behaviors in the prison state system of Guanajuato, Mexico between September 2011 and February 2012. Blood samples were drawn from adult inmates in all State prisons who agreed to participate in this cross-sectional study. Data on risk behaviors were collected by using self-administered questionnaires. The prevalence of HIV, syphilis, HBV, and HCV infection was 0.6% [95% confidence interval (CI) = 0.2-1.1], 0.7% (95% CI = 0.4-1.0), 0.4 (95% CI = 0.04-0.74), and 4.8 (95% CI = 3.6-5.9), respectively. Female inmates had a higher prevalence of HIV (1.5% vs. 0.6%, p = .05), whereas male inmates had a higher prevalence of HCV (1% vs. 5%, p = .008). Twenty percent (n = 443, 95% CI = 15-26) of the participants were tattooed during incarceration, and most of them were tattooed with recycled materials. Around 60% (57%, 95% CI = 49-65) used drugs before incarceration, and 9.2% (n = 205) used injected drugs. During incarceration, 30% (95% CI = 23-39) used drugs and 43 continued injecting (20% of users). Consistent condom use was low among men before incarcerations but decreased by half during incarceration. The highest consistent condom use before incarceration was among men who have sex with men (MSM) (17.7%, 95% CI = 14-22), but it decreased (9%, 95% CI = 3-14) during incarceration. The prevalence of HIV, HBV, HCV, and syphilis in these inmates is higher than that of the local adult population. Most inmates had sex in prison, but few used condoms consistently. Access to condoms is apparently harder for MSM. Interventions to increase condom use, reduce use of shared or recycled materials for tattooing and injecting drugs, and treatment for drug abuse are needed.

Sex Exchange and HIV-related Risk Behaviors among Female Heroin Users in China

This study examines differences in demographic characteristics and HIV-related risk behaviors between Chinese female heroin users who exchanged sex for drugs or money and those who were never involved in sex exchange. A sample of 171 female heroin users was recruited from a detoxification center in China. Female heroin users who exchanged sex for drugs or money were more likely to be unemployed and were at higher risk in both sexual behaviors and injection drug use. Number of sexual partners in the previous year, unemployment, and injection drug use were independently associated with exchange of sex for drugs or money; adjusted odds ratios were 1.2, 3.8, and 2.6, respectively. Findings show that HIV-related risk behaviors are common among female heroin users in China and that HIV harm reduction should be focused on female heroin users who exchange sex for drugs or money.

Moral Panic and the Construction of National Order

This article examines some of the major concepts used to model the Thai AIDS epidemic and to direct interventions, in particular, the concepts of discrete risk groups and of the sequential spread of HIV from group to group in a wave-like fashion which, although they have been largely discredited in the international AIDS literature, retain a high degree of currency in Thailand. I argue that Thailand’s HIV/AIDS epidemic had the effect of bringing sexual practices from the private sphere into the public arena, where the concept of risk group rendered visible the social body of modern Thailand as a hierarchy of risk, with specific groups attributed behaviours necessitating control. This notion found enduring favour in Thailand because it reinforced existing social prejudices about members of groups such as the male underclass, prostitutes and injecting drug users, and legitimated the claims of government and non-government organizations for the monitoring and control of these groups. There has been a high level of consensus over this strategy, and a lack of competing discourses. Thus Thai AIDS discourse has not only failed to transcend state and middle-class notions of morality and normativity, but it has also failed to come to terms with Thailand’s changing sexual cultures.

HIV Sentinel Surveillance in Thailand — An Example for Developing Countries

The intent of the HIV sentinel surveillance program in Thailand, as in other countries, is to provide early warning of pending epidemics so that public health of ficials can intensify prevention and control activities to protect their communities. While the intention is clear, questions remain as to how sentinel groups should be selected and if they predict future HIV occurrence. Every six months, serum is collected in Thailand from a sample of six sentinel groups in all provinces of Thailand for determining the prevalence of HIV infection. Among the sentinel groups, the HIV epidemic is rapidly increasing in female sex-workers, males at STD clinics, and females at antenatal clinics, increasing less rapidly among blood donors, and remaining high among IV drug addicts. Two sentinel groups were found to be useful for predicting the future spread of the epidemic to women attending clinics: lower-class female sex-workers and males attending STD clinics.

Correlates of HIV Testing Experience among Migrant Workers from Myanmar Residing in Thailand: A Secondary Data Analysis

BACKGROUND

Thailand continues to attract an increasing number of migrant workers (MW) from neighboring countries including mainly Myanmar, Cambodia, and Laos; however, little is known about the extent to which MWs from these countries have access to HIV prevention, treatment, and care services. We used data from the baseline survey of the Prevention of HIV/AIDS among MWs in Thailand (PHAMIT-2) project to document the prevalence of, and factors associated with, HIV testing among MWs from Myanmar, the largest group of MWs in Thailand.

METHODS AND FINDINGS

The baseline survey of PHAMIT-2 was conducted in 2010 among MWs from Myanmar, Cambodia, and Laos in 10 purposely-selected provinces of Thailand. Of the 1,034 participants who qualified for the analysis to identify correlates of HIV testing, only 5.3% reported ever having been tested for HIV. Factors associated with HIV testing included having a secondary or higher education level (AOR, 2.58; CI, 1.36-4.90; P = 0.004), being female (AOR, 1.96; CI, 1.05-3.66; P = 0.033), knowing someone who died of AIDS (AOR, 1.81; CI, 1.00-3.27; P = 0.048), working in the fishery sector (AOR, 2.51; CI, 1.28-4.92; P = 0.007), and not having a work permit (AOR, 3.71; CI, 1.36-10.13; P = 0.010).

CONCLUSION

Our study, in addition to revealing significantly low HIV testing among MWs from Myanmar, identifies important barriers to HIV testing which could be addressed through interventions that promote migrants' culturally-sensitive and friendly service, for example by facilitating flow of information about places for HIV testing, availability of language assistance, and ensuring confidentiality of HIV testing.

Prevalence and Correlates of HIV Testing among Young People Enrolled in Non-Formal Education Centers in Urban Chiang Mai, Thailand: A Cross-Sectional Study

BACKGROUND

HIV testing is the gateway to HIV prevention, treatment, and care. Despite the established vulnerability of young Thai people to HIV infection, studies examining the prevalence and correlates of HIV testing among the general population of Thai youth are still very limited. This study investigates socio-demographic, behavioral, and psychosocial factors associated with HIV testing among young Thai people enrolled in Non-formal Education Centers (NFEC) in urban Chiang Mai, Northern Thailand.

METHODS

This was a cross-sectional quantitative study conducted among young unmarried Thai youth--between the ages of 15 and 24--who were enrolled in NFEC in urban Chiang Mai. Multiple logistic regressions were used to identify correlates of "ever tested for HIV" among the sexually active participants.

FINDINGS

Of the 295 sexually active participants, 27.3% reported "ever tested for HIV;" 65.4% "did not consistently use condom;" and 61.7% "had at least 2 lifetime partners." We found that "self-efficacy" (AOR, 4.92; CI, 1.22-19.73); "perception that it is easy to find a location nearby to test for HIV" (AOR, 4.67; CI, 1.21-18.06); "having at least 2 lifetime sexual partners" (AOR, 2.05; CI, 1.09-3.85); and "ever been pregnant or made someone pregnant" (AOR, 4.06; CI, 2.69-9.15); were associated with increased odds of having ever been tested. On the other hand, "fear of HIV test results" (AOR, 0.21; CI, 0.08-0.57) was associated with lower odds of ever having been tested for HIV.

CONCLUSION

The main finding is that a substantially high proportion of Thai youth is engaged in risky sexual behaviors--yet reports low rates of ever having been tested for HIV. This highlights an urgent need to develop appropriate interventions--based on the identified correlates of HIV testing. There is also an urgent need to enhance HIV testing and to promote safer sexual behaviors among young Thai people--particularly those who are out-of-school.

Risk Factors for HIV Infection among Young Thai Men during 2005-2009

Background

Thailand is one of several countries with a continuing generalized HIV epidemic. We evaluated the risk factors for HIV prevalence among 17–29 year old men conscripted by a random process into the Royal Thai Army (RTA) in 8 cohorts from 2005–2009.

Methods

A series of case-cohort studies were conducted among the male RTA conscripts who had been tested for HIV seroprevalence after they were inducted. Men who were HIV positive were compared with a systematic random sample (1 in 30–40) of men from the total population of new conscripts. Each subject completed a detailed risk factor questionnaire.

Results

A total of 240,039 young Thai men were conscripted into the RTA and were screened for HIV seroprevalence between November 2005 and May 2009. Of 1,208 (0.5%) HIV positive cases, 584 (48.3%) men were enrolled into the study. There were 7,396 men who were enrolled as a comparison group. Among conscripts who had an education lower than a college-level, the independent risk factors for HIV infection were age in years (AOR 1.38, 95% CI 1.28–1.48), a history of sex with another man (AOR 3.73, 95% CI 2.70–5.13), HCV infection (AOR 3.89, 95% CI 2.56–5.90), and a history of sex with a female sex worker (FSW) (AOR 1.35, 95% CI 1.10–1.66). Among conscripts who had a college degree, the independent risk factor for HIV infection was a history of sex with another man (AOR 23.04, 95% CI 10.23–51.90). Numbers of sexual partners increased and the age at first sex, as well as the use of condoms for sex with a FSW decreased in successive cohorts.

Conclusion

The HIV seroprevalence among cohorts of 17–29 years old men has remained at about 0.5% overall during 2005–2009. The most significant behavior associated with HIV prevalence was a history of sex with another man. Our data indicate continuing acquisition of HIV among young men in Thailand in recent years, especially among men with a history of same sex behavior.

Epidemiology of HIV/AIDS in the East Azerbaijan Province, Northwest of Iran

Background:

This study was performed in response to the rapid propagation of HIV/AIDS across Iran and its status in this region. Accordingly, an evidence-based program is required to combat this disease.

Objectives:

The present study estimated the prevalence of HIV/AIDS in East Azerbaijan (population: 3,724,000).

Materials and Methods:

We created a database of all positive cases from 1987 to 2012. We also analyzed and described the epidemiological status of HIV/AIDS during a 25-year period by using SPSS.

Results:

In East Azerbaijan, 371 HIV/AIDS cases have been reported, i.e. 1 case per 10,000 population. The vast majority of reported cases (91%, n =338) were men, whereas only 9% (n = 33) were women. The mean age of patients was 30.8 ± 12.3 years. Unsafe drug injection (59%, n = 219) and sexual interaction (13%, n = 48) were the two major modes of HIV transmission. In addition, 7% (n = 25) of patients have been diagnosed with HIV, hepatitis B Virus, and hepatitis C virus simultaneously. Moreover, 60% (n = 205) of men were infected via drug injection, while 82% (n = 27) of women were infected via unprotected sexual interaction (P < 0.001).

Conclusions:

The results indicate a rapid increase in the number of HIV/AIDS cases in East Azerbaijan, necessitating immediate attention and strategies to combat the rapid spread of the disease. Development of provincial and national HIV/AIDS strategies demands more accurate and comprehensive HIV/AIDS surveillance.

Diverse HIV epidemics among people who inject drugs in Thailand: evidence from respondent-driven sampling surveys in Bangkok and Chiang Mai

BACKGROUND

Thailand's long-standing HIV sero-sentinel surveillance system for people who inject drugs (PWID) is confined to those in methadone-based drug treatment clinics and representative data are scarce, especially outside of Bangkok.

METHODS

We conducted probability-based respondent-driven sampling (RDS) surveys in Bangkok (n=738) and Chiang Mai (n=309) to increase understanding of local HIV epidemics and to better inform the planning of evidence-based interventions.

RESULTS

PWID had different epidemiological profiles in these two cities. Overall HIV prevalence was higher in Bangkok (23.6% vs. 10.9%, p<0.001) but PWID in Bangkok are older and appear to have long-standing HIV infections. In Chiang Mai, HIV infections appear to be more recently acquired and PWID were younger and had higher levels of recent injecting and sexual risk behaviors with lower levels of intervention exposure. Methamphetamine was the predominant drug injected in both sites and polydrug use was common although levels and patterns of the specific drugs injected varied significantly between the sites. In multivariate analysis, recent midazolam injection was significantly associated with HIV infection in Chiang Mai (adjusted odds ratio=8.1; 95% confidence interval: 1.2-54.5) whereas in Bangkok HIV status was not associated with recent risk behaviors as infections had likely been acquired in the past.

CONCLUSION

PWID epidemics in Thailand are heterogeneous and driven by local factors. There is a need to customize intervention strategies for PWID in different settings and to integrate population-based survey methods such as RDS into routine surveillance to monitor the national response.

An effective tool for identifying HIV-1 subtypes B, C, CRF01_AE, their recombinant forms, and dual infections in Southeast Asia by the multi-region subtype specific PCR (MSSP) assay

The RV144 Thai vaccine trial has been the only vaccine study to show efficacy in preventing HIV infection. Ongoing molecular surveillance of HIV-1 in Southeast Asia is vital for vaccine development and evaluation. In this study a novel tool, the multi-region subtype specific PCR (MSSP) assay, that was able to identify subtypes B, C, CRF01_AE for Thailand, other Southeast Asian countries, India and China is described. The MSSP assay is based on a nested PCR strategy and amplifies eight short regions distributed along the HIV-1 genome using subtype-specific primers. A panel of 41 clinical DNA samples obtained primarily from opiate users in northern Thailand was used to test the assay performance. The MSSP assay provided 73-100% sensitivity and 100% specificity for the three subtypes in each genome region. The assay was then field-tested on 337 sera from HIV infected northern Thai drug users collected between 1999 and 2002. Subtype distribution was CRF01_AE 77.4% (n=261), subtype B 3.3% (n=11), CRF01_AE/B recombinant 12.2% (n=41), CRF01_AE/C recombinant 0.6% (n=2), and non-typeable 6.5% (n=22). The MSSP assay is a simple, cost-effective, and accurate genotyping tool for laboratory settings with limited resources and is sensitive enough to capture the recombinant genomes and dual infections.

Transmitted HIV drug resistance at the Thai Red Cross anonymous clinic in Bangkok: results from three consecutive years of annual surveillance

OBJECTIVES

The aim of this study was to prospectively survey transmitted drug resistance (TDR) among recently infected individuals (mostly MSM).

METHODS

TDR was determined in prospective annual cohorts of recently HIV-1-infected individuals consecutively recruited from 2008 to 2010. Resistance interpretation was carried out using Stanford Database tools and the WHO surveillance drug resistance mutation list. Kruskal-Wallis and Fisher's exact tests were used to compare demographic and laboratory outcomes.

RESULTS

A total of 299 subjects were enrolled, with 89% MSM. Median viral load was significantly higher in 2010 than in 2008 (P=0.004). Of the 284 analysable reverse transcriptase/protease sequences, TDR to any drug was found in 14/284 (4.9%); 4.0% in 2008, 5.9% in 2009 and 5.3% in 2010, with an increasing trend of TDR to NRTIs and NNRTIs from 2008 to 2010 (P=0.07). Good correlation was found between our data and the WHO threshold surveillance method. Only rilpivirine had significantly higher (P<0.05) predicted resistance in 2010 than in 2008 and 2009.

CONCLUSIONS

A trend towards an increase in TDR in Thailand where the major epidemic is among MSM was observed, but did not reach the WHO-defined high-level threshold (>15%). Attention to prevent the development and spread of drug resistance is needed.

Community health nurses' HIV health promotion and education programmes: a qualitative study

BACKGROUND

Globally, nurses practice in many settings with people with human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS), taking an increasing share of the professional burden of care and helping to reduce morbidity and mortality. International literature is sparse about Thai community nurses providing primary healthcare programmes for people with HIV.

AIM

This study aimed to describe background, experiences and strategies of community nurses regarding their design and delivery of programmes for people living with HIV and AIDS in Chiang Mai Province, Thailand.

DESIGN

This study used a qualitative mixed-methods study employing a qualitative survey and in-depth interviews.

METHODS

Twenty community health nurses from 18 small community hospitals completed a survey comprising demographic data and 13 open-ended questions. Four of them later engaged in in-depth interviews using the same questions. Survey, interview data and field notes were analysed using interpretive content analysis.

FINDINGS

Four themes and six sub-themes portrayed participants' rich experiences and knowledge of HIV health promotion and education; challenges of daily work, discrimination and ethical issues; success through programme diversity comprising promotion of community volunteerism, networking and relationships; and holistic connections with Thai cultural traditions and Buddhism.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Findings help to recognize the diversity, uniqueness and contributions of Thai community nurses regarding culturally appropriate health promotion and education programmes for people living with HIV and AIDS. Findings inform nurses and health officials in and outside of the country to complement innovation in future HIV health promotion and education programmes.

LIMITATIONS

Our sample came from one province of Thailand. Findings might not be reflective of nurses elsewhere.

IMPLICATIONS FOR HEALTH AND NURSING POLICY

Three decades of collective experience in providing holistic and multifaceted HIV and AIDS nursing care, education and health promotion by community health nurses have the potential to effect new and existing policies and protocols on HIV community care in Thailand, but more research is required for this.

Marital sex among people living with HIV receiving antiretroviral treatment in northern Thailand

Before the advent of effective antiretroviral treatment (ART), the sexuality of people living with HIV was mostly discussed in terms of risk. To assess the extent to which ART allows people living with HIV to regain a regular sexual life, we surveyed all HIV-infected people treated in four hospitals in Northern Thailand and a control group from the general population matched by sex, age and residence. Data included socio-demographic and health characteristics, frequency of sexual intercourse in the last month and condom use. Our findings indicate that people living with HIV less often live in steady partnership (50% of the HIV-infected people versus 79% of the controls). After adjusting for factors known to influence sexuality, their probability of being sexually active was estimated to be about half that of the controls. When sexually active, men had a reduced sexual activity compared to controls (2.8 intercourse in the last month versus 4.0), while levels of reported sexual activity were similar among women (2.2 versus 2.8, respectively). Consistent condom use was high among people living with HIV (66% for women and 70% for men).

Risk behaviors and risk factors for HIV infection among participants in the Bangkok tenofovir study, an HIV pre-exposure prophylaxis trial among people who inject drugs

INTRODUCTION

HIV spread rapidly among people who inject drugs in Bangkok in the late 1980s. In recent years, changes in drug use and HIV-associated risk behaviors have been reported. We examined data from the Bangkok Tenofovir Study, an HIV pre-exposure prophylaxis trial conducted among people who inject drugs, to assess participant risk behavior and drug use, and to identify risk factors for HIV infection.

METHODS

The Bangkok Tenofovir Study was a randomized, double-blind, placebo-controlled trial. HIV status was assessed monthly and risk behavior every 3 months. We used generalized estimating equations logistic regression to model trends of injecting, needle sharing, drugs injected, incarceration, and sexual activity reported at follow-up visits; and proportional hazards models to evaluate demographic characteristics, sexual activities, incarceration, drug injection practices, and drugs injected during follow-up as predictors of HIV infection.

RESULTS

The proportion of participants injecting drugs, sharing needles, and reporting sex with more than one partner declined during follow-up (p<0.001). Among participants who reported injecting at enrollment, 801 (53.2%) injected methamphetamine, 559 (37.1%) midazolam, and 527 (35.0%) heroin. In multivariable analysis, young age (i.e., 20-29 years) (p = 0.02), sharing needles (p<0.001), and incarceration in prison (p = 0.002) were associated with incident HIV infection. Participants reporting sex with an opposite sex partner, live-in partner, casual partner, or men reporting sex with male partners were not at a significantly higher risk of HIV infection compared to those who did not report these behaviors.

CONCLUSION

Reports of HIV-associated risk behavior declined significantly during the trial. Young age, needle sharing, and incarceration were independently associated with HIV infection. Sexual activity was not associated with HIV infection, suggesting that the reduction in HIV incidence among participants taking daily oral tenofovir compared to those taking placebo was due to a decrease in parenteral HIV transmission.

Biomedical HIV prevention research and epidemic control in Thailand: two sides of the same coin

For a country with a moderate adult HIV prevalence of just over 1% in 2012, Thailand is widely perceived as having made some extraordinary contributions to the global management of the HIV/AIDS pandemic. It has been promoted as a model of effective HIV control and applauded for its leadership in providing access to antiretroviral treatment. Thailand has also received international recognition for its contribution to biomedical HIV prevention research, which is generally perceived as exceptional. In this paper, Thailand's global role model function as an example of effective HIV/AIDS control and high-quality biomedical HIV prevention research is re-evaluated against the background of currently available data and more recent insights. The results indicate that Thailand's initial response in raising the level of the political significance of HIV/AIDS was indeed extraordinary, which probably prevented a much larger epidemic from occurring. However, this response transpired in unusual extraconstitutional circumstances and its effectiveness declined once the country returned to political normalcy. Available data confirm the country's more than exceptional contribution to biomedical HIV prevention research. Thailand has made a huge contribution to the global management and control of the HIV/AIDS pandemic.

Field Epidemiology and One Health: Thailand’s Experience

Field epidemiology has become a major principle in public health and animal health service. Field epidemiologists are the primary group of professionals responding to outbreaks and other health emergencies who provide evidence-based recommendations for decision makers. In outbreak investigations, their duties are to identify the disease etiology, risk factors or source of an outbreak, and to contain the spread of the disease. Field epidemiology training programs (FETP) recruit professionals with training in medical, veterinary medical and other related health sciences to deal with real-life outbreaks and health problems. Joint training in surveillance and outbreak investigation has led to improved surveillance and control of zoonotic diseases by young professionals from human health and animal health sectors. Field epidemiology training programs for veterinarians (FETPV) is a living branch of a mature FETP which could support the development of wildlife and ecosystem needs under a broad One Health canopy. FETP can be a practical means of actualizing the One Health approach based upon shared needs and mutual benefit. One such model for sustainable, joint capacity development in field epidemiology under a One Health approach has been initiated in Thailand and is being adopted in other Asian countries. The Field Epidemiology Training Network of FETP in Southeast Asia is a useful platform for further strengthening regional disease surveillance and improving response to both public and animal health problems of international concern.

Antiretroviral prophylaxis for HIV infection in injecting drug users in Bangkok, Thailand (the Bangkok Tenofovir Study): a randomised, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Antiretroviral pre-exposure prophylaxis reduces sexual transmission of HIV. We assessed whether daily oral use of tenofovir disoproxil fumarate (tenofovir), an antiretroviral, can reduce HIV transmission in injecting drug users.

METHODS

In this randomised, double-blind, placebo-controlled trial, we enrolled volunteers from 17 drug-treatment clinics in Bangkok, Thailand. Participants were eligible if they were aged 20-60 years, were HIV-negative, and reported injecting drugs during the previous year. We randomly assigned participants (1:1; blocks of four) to either tenofovir or placebo using a computer-generated randomisation sequence. Participants chose either daily directly observed treatment or monthly visits and could switch at monthly visits. Participants received monthly HIV testing and individualised risk-reduction and adherence counselling, blood safety assessments every 3 months, and were offered condoms and methadone treatment. The primary efficacy endpoint was HIV infection, analysed by modified intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00119106.

FINDINGS

Between June 9, 2005, and July 22, 2010, we enrolled 2413 participants, assigning 1204 to tenofovir and 1209 to placebo. Two participants had HIV at enrolment and 50 became infected during follow-up: 17 in the tenofovir group (an incidence of 0·35 per 100 person-years) and 33 in the placebo group (0·68 per 100 person-years), indicating a 48·9% reduction in HIV incidence (95% CI 9·6-72·2; p=0·01). The occurrence of serious adverse events was much the same between the two groups (p=0·35). Nausea was more common in participants in the tenofovir group than in the placebo group (p=0·002).

INTERPRETATION

In this study, daily oral tenofovir reduced the risk of HIV infection in people who inject drugs. Pre-exposure prophylaxis with tenofovir can now be considered for use as part of an HIV prevention package for people who inject drugs.

FUNDING

US Centers for Disease Control and Prevention and the Bangkok Metropolitan Administration.

Ability to access community-based needle-syringe programs and injecting behaviors among drug users: a cross-sectional study in Hunan Province, China

Background

Needle-syringe exchange programs (NSPs) have been substantially rolled-out in China since 2002. Limited studies reported effectiveness of NSPs in a Chinese setting. This study aimed to assess the association between accessibility to NSPs and drug-use risk behaviors of IDUs by investigating primary (self-reported) data of IDUs recruited from NSP sites, community settings and mandatory detoxification centers (MDCs) in Hunan province, China.

Methods

A cross-sectional survey was conducted in Hunan province in 2010. IDU recruits participated in a face-to-face interview to provide information related to their ability to access NSPs, demographic characteristics, and injecting behaviors in the past 30 days.

Results

Of the total 402 participants, 35%, 14% and 51% participants indicated low, medium and high ability to access NSPs in the past 30 days, respectively. A significantly higher proportion of IDUs (77.3%) from the high-access group reported ≤2 injecting episodes per day compared with medium- (46.3%) and low-access (58.8%) groups. Only 29.0% of high-access IDUs re-used syringes before disposal in the past 30 days, significantly lower than those in the medium- (43.1%) and low-access (41.3%) groups. Reported levels of needle/syringe sharing decreased significantly as the ability to access NSPs increased (16.3%, 12.7% and 2.5% in the low, medium and high access groups, respectively). Ninety percent of IDUs recruited from MDCs had low ability to access NSPs.

Conclusions

Increased NSP accessibility is associated with decreased levels of injecting frequency, repetitive use and sharing of injecting equipment among Chinese IDUs. Mandatory detention of IDUs remains as a major barrier for IDUs to access NSPs in China.

Dynamics of the HIV epidemic in southern China: sexual and drug-using behaviours among female sex workers and male clients in Yunnan

To examine the HIV/sexually transmitted infection (STI)-related risk behaviours among community-based female sex workers (FSWs) and their clients in Yunnan Province, China, we performed a cross-sectional study of 705 FSWs and 100 male clients. We found that HIV seroprevalence among FSWs was 13.0% and the most prevalent STI was herpes simplex virus type 2 (HSV-2) (71.1%), followed by Chlamydia trachomatis (18.1%) and syphilis (8.8%). The 20% of FSWs who reported injection drug use also reported needle-sharing behaviours in the last three months. Drug-using FSWs had substantially higher HIV and HSV-2 prevalence, serviced more clients and had a longer history of sex work than non-using FSWs. In total, 57.0% of male clients did not consistently use condoms with FSWs, 2.0% reported illicit drug use and 17.0% had STI symptoms in the last year. The dual risk behaviours of drug-using FSWs and clients place them at greater risk of HIV infection. Intervention programmes must adopt comprehensive methods.

Molecular evolution of the HIV-1 Thai epidemic between the time of RV144 immunogen selection to the execution of the vaccine efficacy trial

The RV144 HIV-1 vaccine trial (Thailand, 2003 to 2009), using immunogens genetically matched to the regional epidemic, demonstrated the first evidence of efficacy for an HIV-1 vaccine. Here we studied the molecular evolution of the HIV-1 epidemic from the time of immunogen selection to the execution of the efficacy trial. We studied HIV-1 genetic diversity among 390 volunteers who were deferred from enrollment in RV144 due to preexisting HIV-1 infection using a multiregion hybridization assay, full-genome sequencing, and phylogenetic analyses. The subtype distribution was 91.7% CRF01_AE, 3.5% subtype B, 4.3% B/CRF01_AE recombinants, and 0.5% dual infections. CRF01_AE strains were 31% more diverse than the ones from the 1990s Thai epidemic. Sixty-nine percent of subtype B strains clustered with the cosmopolitan Western B strains. Ninety-three percent of B/CRF01_AE recombinants were unique; recombination breakpoint analysis showed that these strains were highly embedded within the larger network that integrates recombinants from East/Southeast Asia. Compared to Thai sequences from the early 1990s, the distance to the RV144 immunogens increased 52% to 68% for CRF01_AE Env immunogens and 12% to 29% for subtype B immunogens. Forty-three percent to 48% of CRF01_AE sequences differed from the sequence of the vaccine insert in Env variable region 2 positions 169 and 181, which were implicated in vaccine sieve effects in RV144. In conclusion, compared to the molecular picture at the early stages of vaccine development, our results show an overall increase in the genetic complexity of viruses in the Thai epidemic and in the distance to vaccine immunogens, which should be considered at the time of the analysis of the trial results.

Sex tourist risk behaviour--an on-site survey among Swedish men buying sex in Thailand

BACKGROUND

Thailand is not only a popular destination for Swedish tourists, it is also the foreign country where the largest numbers of Swedish males contract HIV. This study investigated sexual risk-behaviour of Swedish men who have sex with commercial sex workers (CSW) in Thailand.

METHOD

Eligible men were approached on location in red-light districts of Pattaya and Bangkok with a self-administered multiple-choice questionnaire in December 2010. The data collected was analysed using SPSS version 18 generating cross-tabs, independent sample t-test, univariate and multivariate logistic regression.

RESULTS

In total, 158 questionnaires were included in the analyses. The results indicated that 63% of the study sample had lifetime experience of sexual intercourse with CSWs, while 48% of the respondents indicated that they were likely to pay for sex during their present trip. 71% of the lifetime sex-buyers reported consistent use of condoms in the past. Out of the men that were planning to have sex with a CSW in the near future, 80% reported that they would use condoms consistently. While most of these men always use, and plan on always using a condom when having sex with a CSW, some do so inconsistently or not at all. The study found that those reporting inconsistent condom use when engaging in sexual intercourse with Thai CSWs assessed the risk of becoming infected with HIV to be significantly lower than those who used condoms consistently (p < 0.005).

CONCLUSIONS

Inconsistent condom use by Swedish male tourists to Thailand when having sex with CSWs puts them at risk of contracting HIV and other STIs, and seems to be associated with a lower assessment of the risk of becoming infected with HIV.

HIV epidemic in Asia: optimizing and expanding vaccine development

The recent evidence in Thailand for protection from acquisition of HIV through vaccination in a mostly heterosexual population has generated considerable hope. Building upon these results and the analysis of the correlates of risk remains among the highest priorities. Improved vaccine concepts including heterologous prime-boost regimens, improved proteins with potent adjuvants and new vectors expressing mosaic antigens may soon enter clinical development to assess vaccine efficacy in men who have sex with men. Identifying heterosexual populations with sufficient HIV incidence for the conduct of efficacy trials represents perhaps the main challenge in Asia. Fostering translational research efforts in Asian countries may benefit from the development of master strategic plans and program management processes.

Theory and action for effective condom promotion: illustrations from a behavior intervention project for sex workers in singapore

Acquired immunodeficiency virus (AIDS) and sexually transmitted diseases (STD) control programs targeted at sex workers have focused on condom use. Reasons for non-condom use among female brothel-based sex workers in Singapore were found to be low self-efficacy, lack of condom negotiation skills, and barriers such as fear of annoying clients. Green's PRECEDE framework and Bandura's self-efficacy theory were applied to develop a project aimed at equipping sex workers with negotiation skills, overcoming barriers to condom use, and gathering support from brothel keepers and peers. The experimental group showed significant improvements in negotiation skills and outcome behavior of always refusing sex without a condom, that were supported by a decline in gonorrhea incidence. This article describes the application of behavior change and health education theories to achieve reduction in gonorrhea risk.

The dynamics of condom use with regular and casual partners: analysis of the 2006 National Sexual Behavior Survey of Thailand

OBJECTIVE

This study aims to determine factors associated with levels of condom use among heterosexual Thai males in sex with regular partners and in sex with casual partners.

METHODS

The data used in this study are from the national probability sample of the 2006 National Sexual Behavior Study, the third nationally representative cross-sectional survey in Thailand. A subtotal of 2,281 men were analyzed in the study, including young (18-24) and older (25-59) adults who were residents of rural areas of Thailand, non-Bangkok urban areas, and Bangkok. Two outcomes of interest for this analysis are reported condom use in the past 12 months by males in relationships with the most recent regular and casual partners who were not sex workers. Chi-square statistics, bivariate regressions and the proportional odds regression models are used in the analysis.

RESULTS

Condom use for men with their regular partner is revealed to be positively related to education, knowledge of condom effectiveness, and pro-condom strategy, and negatively related to non-professional employment, status of registered marriage, and short relationship duration. Condom use with casual partner is positively determined by education, condom knowledge, non-professional occupation, short relationship duration, and lack of history of paid sex.

CONCLUSION

The national survey emphasized the importance of risk perceptions and condom motivations variables in explaining condom use among men in Thailand. These factors include not only education and knowledge of condom effectiveness and pro-condom strategy but also types of partners and their relationship context and characteristics. Program intervention to promote condom use in Thailand in this new era of predominant casual sex rather than sex with sex workers has to take into account more dynamic partner-based strategies than in the past history of the epidemics in Thailand.

Enrollment characteristics and risk behaviors of injection drug users participating in the Bangkok Tenofovir Study, Thailand

Background

The Bangkok Tenofovir Study was launched in 2005 to determine if pre-exposure prophylaxis with tenofovir will reduce the risk of HIV infection among injecting drug users (IDUs). We describe recruitment, screening, enrollment, and baseline characteristics of study participants and contrast risk behavior of Tenofovir Study participants with participants in the 1999–2003 AIDSVAX B/E Vaccine Trial.

Methods

The Bangkok Tenofovir Study is an ongoing, phase-3, randomized, double-blind, placebo-controlled, HIV pre-exposure prophylaxis trial of daily oral tenofovir. The Tenofovir Study and the Vaccine Trial were conducted among IDUs at 17 drug-treatment clinics in Bangkok. Tenofovir Study sample size was based on HIV incidence in the Vaccine Trial. Standardized questionnaires were used to collect demographic, risk behavior, and incarceration data. The Tenofovir Study is registered with ClinicalTrials.gov, number-NCT00119106.

Results

From June 2005 through July 2010, 4094 IDUs were screened and 2413 enrolled in the Bangkok Tenofovir Study. The median age of enrolled participants was 31 years (range, 20–59), 80% were male, and 63% reported they injected drugs during the 3 months before enrollment. Among those who injected, 53% injected methamphetamine, 37% midazolam, and 35% heroin. Tenofovir Study participants were less likely to inject drugs, inject daily, or share needles (all, p<0.001) than Vaccine Trial participants.

Discussion

The Bangkok Tenofovir Study has been successfully launched and is fully enrolled. Study participants are significantly less likely to report injecting drugs and sharing needles than participants in the 1999–2003 AIDSVAX B/E Vaccine Trial suggesting HIV incidence will be lower than expected. In response, the Bangkok Tenofovir Study enrollment was increased from 1600 to 2400 and the study design was changed from a defined 1-year follow-up period to an endpoint-driven design. Trial results demonstrating whether or not daily oral tenofovir reduces the risk of HIV infection among IDUs are expected in 2012.

Characteristics of HIV epidemics driven by men who have sex with men and people who inject drugs

PURPOSE OF REVIEW

To highlight the latest developments in mathematical transmission modelling of HIV epidemics among men who have sex with men (MSM) and people who inject drugs (PWID).

RECENT FINDINGS

Mathematical approaches have been applied to a wide range of topics in recent HIV research. Epidemiological models have evaluated past and forecasted future trends in prevalence and incidence, evaluated innovative behaviour modification strategies and public health programmes aimed at minimizing risk, and explored the potential impact of various biomedical interventions. MSM have developed new risk reduction strategies which models have deemed to be effective at a population level only in certain settings, such as when there are high rates of HIV testing. Modelling has also indicated that persistent circulation of drug-resistant HIV strains is likely to become an inevitable public health issue in the near future in resource-rich settings among MSM. Models have also recently been used to demonstrate that needle and syringe programmes for harm reduction among PWID are effective and cost-effective.

SUMMARY

Mathematical modelling is particularly amenable to single population groups of concentrated HIV epidemics, such as among MSM and PWID. Models have been utilized to evaluate innovative areas in clinical, biomedical and public health research that cannot be conducted in other population groups. Future directions are likely to include evaluation of specific public health programmes and providing understanding of the importance of specific treatment regimens and incidence and interaction of comorbid conditions associated with HIV.

Bridging populations-sexual risk behaviors and HIV prevalence in clients and partners of female sex workers, Bangkok, Thailand 2007

The aim of this study is to estimate HIV prevalence and assess sexual behaviors in a high-risk and difficult-to-reach population of clients of female sex workers (FSWs). A modified variation of respondent-driven sampling was conducted among FSWs in Bangkok, where FSWs recruited 3 FSW peers, 1 client, and 1 nonpaying partner. After informed consent was obtained, participants completed a questionnaire, were HIV-tested, and were asked to return for results. Analyses were weighted to control for the design of the survey. Among 540 FSWs, 188 (35%) recruited 1 client, and 88 (16%) recruited 1 nonpaying partner. Clients' median age was 38 years. HIV prevalence was 20% and was associated with younger age at first sexual experience [relative risk (RR) = 3.10, 95% confidence interval (CI) 1.16-8.24] and condom use during last sexual encounter with regular partner (RR = 3.97, 95% CI 1.09-14.61). Median age of nonpaying partners was 34 years, and HIV prevalence was 15.1%. There were 56 discordant FSW-client pairs and 14 discordant FSW-nonpaying partner pairs. Condom use was relatively high among discordant FSW-client pairs (90.1%) compared to discordant FSW-nonpaying partner pairs (18.7%). Results suggest that sexual partners of FSWs have a high HIV prevalence and can be a bridge for HIV transmission to other populations. Findings also highlight the importance of initiating surveillance and targeted programs for FSW partners, and demonstrate a recruitment method for hard-to-reach populations.

HIV prevalence, sexual and behavioral correlates among Shan, Hill tribe, and Thai male sex workers in Northern Thailand

This paper reports demographic characteristics, HIV prevalence, and correlates among male sex workers (MSW) in Chiangmai, Thailand. A behavioral assessment survey was included as part of the Thailand Ministry of Public Health HIV sentinel surveillance conducted during June 2003. A sample of 181 MSW from 14 sex establishments around Chiangmai who self-identified as sex workers were interviewed. Non-Thai MSW made up half of the sample (48.6%), with the majority being of Shan ethnicity (64.7%). Thai MSW were significantly more likely to report having had receptive anal intercourse (38.0% vs. 11.8%, p < 0.001) and to have higher HIV prevalence than non-Thai MSW(11.8% vs. 3.4%, p < 0.001). In multivariate analysis, having one or more than one steady male partner in the past month (Odds Ratio: 5.56, 95% Confidence Intervals: 1.13-27.27 and 8.29, 2.01-34.20, respectively), and being older than 21 years (2.26, 1.04-4.90) were significantly and independently associated with prevalent HIV infection. While Thai MSW had higher HIV prevalence and engage in riskier activities, culturally appropriate education and outreach activities are still needed for the large number of ethnic minority MSW, particularly Shan MSW.

Needle and syringe programs in Yunnan, China yield health and financial return

Background

As a harm reduction strategy in response to HIV epidemics needle and syringes programs (NSPs) were initiated throughout China in 2002. The effectiveness of NSPs in reducing the spread of infection in such an established epidemic is unknown. In this study we use data from Yunnan province, the province most affected by HIV in China, to (1) estimate the population benefits in terms of infections prevented due to the programs; (2) calculate the cost-effectiveness of NSPs.

Methods

We developed a mathematical transmission model, informed by detailed behavioral and program data, which accurately reflected the unique HIV epidemiology among Yunnan injecting drug users (IDUs) in the presence of NSPs. We then used the model to estimate the likely epidemiological and clinical outcomes without NSPs and conducted a health economics analysis to determine the cost-effectiveness of the program.

Results

It is estimated that NSPs in Yunnan have averted approximately 16-20% (5,200-7,500 infections) of the expected HIV cases since 2002 and led to gains of 1,300-1,900 DALYs. The total $1.04 million spending on NSPs from 2002 to 2008 has resulted in an estimated cost-saving over this period of $1.38-$1.97 million due to the prevention of HIV and the associated costs of care and management.

Conclusion

NSPs are not only cost-effective but cost-saving in Yunnan. Significant scale-up of NSPs interventions across China and removal of the societal and political barriers that compromise the effects of NSPs should be a health priority of the Chinese government.

Phylodynamics of HIV-1 from a phase III AIDS vaccine trial in Bangkok, Thailand

BACKGROUND

In 2003, a phase III placebo-controlled trial (VAX003) was completed in Bangkok, Thailand. Of the 2,546 individuals enrolled in the trial based on high risk for infection through injection drug use (IDU), we obtained clinical samples and HIV-1 sequence data (envelope glycoprotein gene gp120) from 215 individuals who became infected during the trial. Here, we used these data in combination with other publicly available gp120 sequences to perform a molecular surveillance and phylodynamic analysis of HIV-1 in Thailand.

METHODOLOGY AND FINDINGS

Phylogenetic and population genetic estimators were used to assess HIV-1 gp120 diversity as a function of vaccination treatment, viral load (VL) and CD4(+) counts, to identify transmission clusters and to investigate the timescale and demographics of HIV-1 in Thailand. Three HIV-1 subtypes were identified: CRF01_AE (85% of the infections), subtype B (13%) and CRF15_AE (2%). The Bangkok IDU cohort showed more gp120 diversity than other Asian IDU cohorts and similar diversity to that observed in sexually infected individuals. Moreover, significant differences (P<0.02) in genetic diversity were observed in CRF01_AE IDU with different VL and CD4(+) counts. No phylogenetic structure was detected regarding any of the epidemiological and clinical factors tested, although high proportions (35% to 50%) of early infections fell into clusters, which suggests that transmission chains associated with acute infection play a key role on HIV-1 spread among IDU. CRF01_AE was estimated to have emerged in Thailand in 1984.5 (1983-1986), 3-6 years before the first recognition of symptomatic patients (1989). The relative genetic diversity of the HIV-1 population has remained high despite decreasing prevalence rates since the mid 1990s.

CONCLUSIONS

Our study and recent epidemiological reports indicate that HIV-1 is still a major threat in Thailand and suggest that HIV awareness and prevention needs to be strengthened to avoid AIDS resurgence.

Current progress in the development of a prophylactic vaccine for HIV-1

Since its discovery and characterization in the early 1980s as a virus that attacks the immune system, there has been some success for the treatment of human immunodeficiency virus-1 (HIV-1) infection. However, due to the overwhelming public health impact of this virus, a vaccine is needed urgently. Despite the tireless efforts of scientist and clinicians, there is still no safe and effective vaccine that provides sterilizing immunity. A vaccine that provides sterilizing immunity against HIV infection remains elusive in part due to the following reasons: 1) degree of diversity of the virus, 2) ability of the virus to evade the hosts' immunity, and 3) lack of appropriate animal models in which to test vaccine candidates. There have been several attempts to stimulate the immune system to provide protection against HIV-infection. Here, we will discuss attempts that have been made to induce sterilizing immunity, including traditional vaccination attempts, induction of broadly neutralizing antibody production, DNA vaccines, and use of viral vectors. Some of these attempts show promise pending continued research efforts.

Injection prevalence and risks among male ethnic minority drug users in northern Thailand

Thailand's rate of HIV due to drug use is increasing, and nearly one-half of clients at a drug treatment centre in the north are from marginalized ethnic minority groups. We describe and compare socio-demographics, drug use, and sexual practices across ethnic minority people presenting for treatment at the Northern Drug Treatment Center, Mae Rim, Thailand. A prevalence study was conducted between February 1999 and January 2000. Trained interviewers administered a baseline questionnaire to 1,865 people admitted to the Northern Drug Dependence Treatment Center. Ethnic minority (Karen, Akha, Hmong, Lisu, and Lahu) males were included in this analysis (n = 629). Between 7% and 28% of each minority group had ever injected drugs (p = 0.002). Ninety-five per cent of men ever injecting had used heroin. Younger age, speaking Thai language, having a job with higher contact with Thais, and prior drug detoxification were significantly associated with injection in multivariate analysis, while Hmong and Lisu ethnicity were protective. Using occupation and language as proxies, contact with Thais and concomitant acculturation may be a risk for injection among this population. The inadvertent consequences of acculturation as it relates to injection and HIV risk must be addressed.

Essential elements of strategic information systems to guide focused HIV responses in south and south-east Asia

Strategic information is fundamental to the formulation and delivery of effective HIV programmes, but generating that information is a complex process, for which most countries in south and south-east Asia lack capacity and supporting structures. Although most countries in this region have made tremendous strides in collecting relevant data, advances in the ability to translate that data into strategic information and evidence for action, have not kept pace. To overcome these shortcomings, this paper presents a comprehensive approach to collecting strategic information and building the capacity to use it effectively, which is based on experience in the successful use of data in different countries in south and south-east Asia. The system recommended here requires that staff and resources carry out four major functions: implement an early alert and response system allowing for the timely collection, synthesis and use of information to respond quickly to emerging epidemics; carefully analyze data to develop policy scenarios and resource projections to guide decision-making; periodically evaluate the impact of the current response and make recommendations to improve it; and engage policy-makers in ways that proactively promote improvements to current programmes based on evidence. At present, countries in this region are carrying out these functions in an ad-hoc and uncoordinated manner, if at all. The establishment and resourcing of structures dedicated to fulfilling these functions in an organized and coordinated manner are required to counteract the formidable barriers and challenges that inhibit the use of Asia's wealth of data for maximum benefit.

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.