Continued high HIV-1 incidence in a vaccine trial preparatory cohort of injection drug users in Bangkok, Thailand

Risk factors associated with human immunodeficiency virus infection in blood donors in Iran: A case-control study

BACKGROUND

Despite setting the stringent criteria for the selection of safe donors, some human immunodeficiency virus (HIV)-positive volunteers manage to give blood. Considering the window period of screening tests, this could endanger the safety of blood supply.

MATERIALS AND METHODS

A frequency match case-control study was conducted on HIV-positive and negative blood donors in Iran from 2007 to 2008. Overall, 61 HIV-positive and 224 HIV-negative blood donors were selected as cases and controls, respectively. Two groups were matched for confounding factors. An identical questionnaire was used to assess risk factors. Univariate regression analysis for calculating crude odds ratio (OR) and 95% confidence interval (CI) was used for detecting eligibility of risk factors to enter the final model. The exposures with P < 0.1 were entered in the logistic regression model. Adjusted ORs with P < 0.05 and 95% CIs were reported for statistically significant variables.

RESULTS

Significant effects were detected for the following variables: education, job, tattoo, intravenous (IV) drug abuse, imprisonment, and risky sexual behavior. However, based on multiple analyses, education, IV drug abuse, imprisonment, and risky sexual behavior remain significant.

CONCLUSION

The majority of our findings are in parallel with the other studies performed in other countries. To increase blood safety, special attention should be paid to illiterate, first-time blood donors who are in the 25-40 age range. In addition, having the history of IV drug abuse, imprisonment and risky sexual behaviors put the blood donors more at risk of infecting HIV.

Adaptive lasso for the Cox regression with interval censored and possibly left truncated data

We propose a penalized variable selection method for the Cox proportional hazards model with interval censored data. It conducts a penalized nonparametric maximum likelihood estimation with an adaptive lasso penalty, which can be implemented through a penalized EM algorithm. The method is proven to enjoy the desirable oracle property. We also extend the method to left truncated and interval censored data. Our simulation studies show that the method possesses the oracle property in samples of modest sizes and outperforms available existing approaches in many of the operating characteristics. An application to a dental caries data set illustrates the method's utility.

Hepatitis C virus infection among people who inject drugs in Bangkok, Thailand, 2005-2010

BACKGROUND

Approximately 1% of adults in Thailand are infected with hepatitis C virus (HCV). New direct-acting antiviral agents achieve sustained virologic responses in >95% of HCV-infected patients and are becoming available in countries around the world. To prepare for new HCV treatment options in Thailand, this study characterized HCV infections among people who inject drugs (PWID) in Bangkok.

METHODS

The Bangkok Tenofovir Study (BTS) was a pre-exposure prophylaxis trial conducted among PWID, 2005-2013. Blood specimens were randomly selected from PWID screened for the BTS, to test for anti-HCV antibody and HCV RNA. The HVR1 region was amplified by polymerase chain reaction, using multiplex primer sets with unique identifier sequences; amplification products were pooled in sets of 25; and consensus sequencing was performed to characterize individual HCV genotypes.

RESULTS

The median age of 3679 participants tested for anti-HCV antibody was 31 years, 3016 (82.0%) were male and 447 (12.2%) were HIV infected. The prevalence of anti-HCV antibody was 44.3%. The adjusted odds of testing positive for anti-HCV antibody were higher in men (adjusted odds ratio [aOR] 3.2, 95% confidence interval [CI] 2.4-4.3), those aged 40 years or older (aOR 2.7, 95% CI 2.1-3.5), those who had more than a primary school education (aOR 1.7, 95% CI 1.4-2.1), and those who tested HIV positive (aOR 5.2, 95% CI 3.7-7.4). HCV RNA was detected in 644 (81.3%) of the 792 anti-HCV antibody-positive specimens, yielding an HCV RNA-positive prevalence of 36.0% (95% CI 33.8-38.2). Among a random sample of 249 of the 644 specimens, 218 could be characterized, and the most common HCV subtypes were 1a (30.3%), 1b (12.8%), 3a (35.8%), 3b (6.9%) and 6n (8.7%).

CONCLUSION

The prevalence of anti-HCV antibody among PWID was 44.3% and more than one third (36.0%) were HCV RNA positive. Genotypes 1, 3 and 6 accounted for all typable infections. As the government of Thailand considers introduction of direct-acting antiviral medications for people with hepatitis C, it will be important to ensure that the medications target these subtypes.

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.

High HIV seroconversion rate in hepatitis C virus-infected drug users followed in a harm reduction unit: a lost opportunity for preexposure prophylaxis

OBJECTIVES

Current harm reduction strategies will probably remain insufficient to eliminate HIV transmission among drug users. We aimed to estimate the HIV seroconversion rate among drug users followed at a harm reduction unit (HRU) to evaluate the potential use of preexposure prophylaxis as a prevention tool.

DESIGN AND METHODS

A cohort of drug users has been followed at an HRU in Madrid between 2013 and 2016. Individuals who were HIV negative at baseline and who had at least one retest for HIV infection were eligible. Kaplan-Meier methods were employed to estimate the incidence density.

RESULTS

A total of 954 drug users had at least an HIV test. At baseline, 260 were HIV negative and had at least one follow-up HIV test. After 330.89 person-years of risk for HIV infection, 10 (3.8%) seroconverted. Overall incidence density of HIV seroconversion was 3.02 [95% confidence interval (CI); 1.4-5.5] per 100 person-years, with differences according to hepatitis C virus (HCV) serostatus: 1.17 (95% CI; 0.1-4.2) per 100 person-years in negative HCV individuals and 4.98 (95% CI; 2.1-9.8) per 100 person-years in positive HCV individuals. In the multivariable analysis, infection with HCV remained independently associated with time to HIV seroconversion (adjusted hazard ratio = 6.43; 95% CI; 1.1-36.5, P = 0.035).

CONCLUSION

Despite efforts in HIV prevention in a HRU, a high incidence of HIV was found among active drug users. Positive HCV status is a strong predictor of HIV seroconversion. In this context, preexposure prophylaxis implementation should be considered as an additional tool for HIV prevention in this population.

HIV infection among persons who inject drugs: ending old epidemics and addressing new outbreaks

AIDS among persons who inject drugs, first identified in December 1981, has become a global epidemic. Injecting drug use has been reported in 148 countries and HIV infection has been seen among persons who inject drugs in 61 countries. Many locations have experienced outbreaks of HIV infection among persons who inject drugs, under specific conditions that promote very rapid spread of the virus. In response to these HIV outbreaks, specific interventions for persons who inject drugs include needle/syringe exchange programs, medicated-assisted treatment (with methadone or buprenorphine) and antiretroviral therapy. Through a 'combined prevention' approach, these interventions significantly reduced new HIV infections among persons who inject drugs in several locations including New York City, Vancouver and France. The efforts effectively ended the HIV epidemic among persons who inject drugs in those locations. This review examines possible processes through which combined prevention programs may lead to ending HIV epidemics. However, notable outbreaks of HIV among persons who inject drugs have recently occurred in several countries, including in Athens, Greece; Tel-Aviv, Israel; Dublin, Ireland; as well as in Scott County, Indiana, USA. This review also considers different factors that may have led to these outbreaks. We conclude with addressing the remaining challenges for reducing HIV infection among persons who inject drugs.

HIV pre-exposure prophylaxis and health and community systems in the Global South: Thailand case study

INTRODUCTION

Pre-exposure prophylaxis (PrEP) is recommended by the World Health Organization as an effective method of HIV prevention for individuals at risk for infection. In this paper, we describe the unique role that Thailand has played in the global effort to combat the HIV epidemic, including its role in proving the efficacy of PrEP, and discuss the opportunities and challenges of implementing PrEP in a middle-income country.

DISCUSSION

Thailand was one of the first countries in the world to successfully reverse a generalized HIV epidemic. Despite this early success, HIV prevalence has remained high among people who inject drugs and has surged among men who have sex with men (MSM) and transgender women (TGW). Two pivotal trials that showed that the use of oral antiretroviral medication as PrEP can reduce HIV transmission were conducted partially or entirely at Thai sites. Demonstration projects of PrEP, as well as clinical trials of alternative PrEP regimens, began or will begin in 2014-2015 in Thailand and will provide additional data and experience on how to best implement PrEP for high-risk individuals in the community. Financing of drug costs, the need for routine laboratory monitoring and lack of awareness about PrEP among at-risk groups all present challenges to the wider implementation of PrEP for HIV prevention in Thailand.

CONCLUSIONS

Although significant challenges to wider use remain, PrEP holds promise as a safe and highly effective method to be used as part of a combined HIV prevention strategy for MSM and TGW in Thailand.

High Mortality Among Non-HIV-Infected People Who Inject Drugs in Bangkok, Thailand, 2005-2012

OBJECTIVES

We examined the causes of hospitalization and death of people who inject drugs participating in the Bangkok Tenofovir Study, an HIV preexposure prophylaxis trial.

METHODS

The Bangkok Tenofovir Study was a randomized, double-blind, placebo-controlled trial conducted during 2005 to 2012 among 2413 people who inject drugs. We reviewed medical records to define the causes of hospitalization and death, examined participant characteristics and risk behaviors to determine predictors of death, and compared the participant mortality rate with the rate of the general population of Bangkok, Thailand.

RESULTS

Participants were followed an average of 4 years; 107 died: 22 (20.6%) from overdose, 13 (12.2%) from traffic accidents, and 12 (11.2%) from sepsis. In multivariable analysis, older age (40-59 years; P = .001), injecting drugs (P = .03), and injecting midazolam (P < .001) were associated with death. The standardized mortality ratio was 2.9.

CONCLUSIONS

People who injected drugs were nearly 3 times as likely to die as were those in the general population of Bangkok and injecting midazolam was independently associated with death. Drug overdose and traffic accidents were the most common causes of death, and their prevention should be public health priorities.

Influence of different drugs on HIV risk in people who inject: systematic review and meta-analysis

AIMS

To assess systematically the risk of HIV acquisition by type of drug injected across different settings.

METHODS

A systematic review and meta-analysis were conducted. Databases were searched for studies of HIV incidence in people who inject different drugs (PWID). Pooled HIV incidence rate ratio (IRR) was used to compare HIV risk between injecting and not-injecting a given drug, when possible, or otherwise with those reported not to have injected the substance. Pooled estimates of crude IRR were derived using random-effects models. Variations in IRR were assessed in subgroup analyses, by drug and geographical region.

RESULTS

Of 5779 studies screened, 15 were included. HIV incidence was reported for people injecting cocaine (eight: North America, Europe), amphetamine-type stimulants (ATS) (four: Western and Eastern Europe, Asia), heroin (11: all settings), opiate-stimulants (four: North America, Western and Eastern Europe) and opiates-sedatives (five: Europe, Asia). HIV risk in cocaine injectors was 3.6 times 95% confidence interval (CI) = 2.8-4.7, I(2)  = 0%; n = 4) that of non-injectors and 3.0 for ATS injectors (95% CI = 2.2-4.1, I(2)  = 0%; n = 2). Higher sexual risk was reported in cohorts injecting stimulants. Compared to not-injecting, HIV IRR was 2.8 (95% CI = 1.7-4.7, I(2)  = 77%; n=6) for all heroin injectors and 3.5 (95% CI = 2.3-5.2, I(2)  = 40%; n=5) for heroin injectors in Asia and Europe.

CONCLUSION

The risk of HIV acquisition in people who inject drugs appears to vary by drug type but differences are not statistically significant, precluding conclusive grading of risk.

Methadone maintenance treatment program in prisons from the perspective of medical and non-medical prison staff: a qualitative study in Iran

BACKGROUND

As one of the most important components of harm reduction strategy for high-risk groups, following the HIV epidemics, Methadone Maintenance Treatment (MMT) has been initiated in prisoners since 2003. In this paper, we aimed to assess the advantages and shortcomings of the MMT program from the perspective of people who were involved with the delivery of prison healthcare in Iran.

METHODS

On the basis of grounded theory and through conducting 14 Focus Group Discussions (FGDs), 7 FGDs among physicians, consultants, experts, and 7 FGDs among directors and managers of prisons (n= 140) have been performed. The respondents were asked about positive and negative elements of the MMT program in Iranian prisons.

RESULTS

This study included a total of 48 themes, of which 22 themes were related to advantages and the other 26 were about shortcomings of MMT programs in the prisons. According to participants' views "reduction of illegal drug use and high-risk injection", "reduction of potentially high-risk behaviors" and "making positive attitudes" were the main advantages of MMT in prisons, while issues such as "inaccurate implementation", "lack of skilled manpower" and "poor care after release from prison" were among the main shortcomings of MMT program.

CONCLUSION

MMT program in Iran's prisons has achieved remarkable success in the field of harm reduction, but to obtain much more significant results, its shortcomings and weaknesses must be also taken into account by policy-makers.

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.

Can HIV and Hepatitis C Virus Infection be Eliminated Among Persons Who Inject Drugs?

HIV and hepatitis C virus (HCV) infection are readily transmitted among persons who inject drugs. The HIV and HCV epidemics have expanded rapidly, becoming global health issues. Combined prevention has been implemented to reduce injection and sexual transmission of HIV and HCV among persons who inject drugs. Reductions in risky injection and sexual behavior have led to dramatic reductions in HIV in many countries. Whether comparable reductions in HCV transmission can be achieved has yet to be determined. Eliminating HIV and HCV among persons who inject drugs will require considerable resources and commitment, particularly in low and middle income countries.

Global Dispersal Pattern of HIV Type 1 Subtype CRF01_AE: A Genetic Trace of Human Mobility Related to Heterosexual Sexual Activities Centralized in Southeast Asia

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) subtype CRF01_AE originated in Africa and then passed to Thailand, where it established a major epidemic. Despite the global presence of CRF01_AE, little is known about its subsequent dispersal pattern.

METHODS

We assembled a global data set of 2736 CRF01_AE sequences by pooling sequences from public databases and patient-cohort studies. We estimated viral dispersal patterns, using statistical phylogeographic analysis run over bootstrap trees estimated by the maximum likelihood method.

RESULTS

We show that Thailand has been the source of viral dispersal to most areas worldwide, including 17 of 20 sampled countries in Europe. Japan, Singapore, Vietnam, and other Asian countries have played a secondary role in the viral dissemination. In contrast, China and Taiwan have mainly imported strains from neighboring Asian countries, North America, and Africa without any significant viral exportation.

DISCUSSION

The central role of Thailand in the global spread of CRF01_AE can be probably explained by the popularity of Thailand as a vacation destination characterized by sex tourism and by Thai emigration to the Western world. Our study highlights the unique case of CRF01_AE, the only globally distributed non-B clade whose global dispersal did not originate in Africa.

Screening for acute HIV infections and estimating HIV incidence among female sex workers from low-grade venues in Guangxi, China

Background

Guangxi has become one of the provinces with the most severe HIV-1 epidemic in China, where heterosexual contact is the dominant transmission route. However, data of acute HIV infections and HIV incidence among female sex workers (FSWs) from low-grade venues are scant.

Methods

A cross-sectional survey was performed among FSWs from low-grade venues in Guangxi. HIV antibody screening was performed by rapid testing (RT). HIV antibody–negative specimens were screened by pooled nucleic acid amplification testing (NAAT) for acute HIV infections. HIV antibody-positive specimens were further analyzed by Western blot (WB), followed by an HIV-1 BED capture enzyme immunoassay (BED-CEIA) to identify the recent infections. HIV-1 incidence was estimated by the data of pooled NAAT and BED-CEIA, respectively.

Results

A total of 7936 FSWs were recruited and answered the questionnaires. We successfully collected the blood samples from 6469 (81.5%) participants, of which 139 (2.1%) were HIV antibody–positive and 6330 (97.9%) were HIV antibody-negative by RT. With pooled NAAT, 7 cases were found to be HIV RNA positive, representing an additional 5.0% of HIV-infected persons and an estimated HIV incidence of 1.45 (95% CI: 1.17–1.76) per 100 person years. There were 137 positive and 2 indeterminate by WB, of which 124 (90.5%) positive specimens were subjected to BED-CEIA testing identifying 28 recent infections. The HIV incidence determined by BED-CEIA testing was 1.04 (95% CI: 0.65–1.43) per 100 person years. The overall prevalence of HIV among FSWs from low-grade venues in Guangxi was 2.2% (95% CI: 1.9–2.6).

Conclusions

We found that the addition of HIV RNA screening to routine HIV antibody testing significantly improved the detection of HIV infection among FSWs from low-grade venues in Guangxi. Our findings also provided the useful baseline data of HIV incidence among this population for targeting local HIV prevention, intervention, monitoring and treatment.

High HIV incidence in a cohort of male injection drug users in Delhi, India

BACKGROUND

India has an estimated 177,000 injection drug users (IDU) with a national HIV prevalence of 7.14%. Reliable estimates of HIV incidence are not available for this population.

METHODS

We report HIV incidence in a cohort of male, HIV-negative IDUs recruited through peer-referral, targeted outreach and as walk-in clients in Delhi from May to October, 2011. Fourth-generation Antigen-Antibody tests were used to diagnose new infections and results were confirmed using Western blot tests. HIV incidence based on HIV seroconversion was calculated as number of events/person-years. Cox regression was used to identify significant (p<0.05) seroconversion predictors.

RESULTS

A total of 2790 male HIV-negative IDUs were recruited at baseline; 67.4% (n=1880) returned for their first follow-up visit and 96% (n=1806) underwent HIV testing. Participants were followed for a median of 9.7 months. A total of 112 new HIV infections occurred over a cumulative 1398.5 person-years of follow-up resulting in an incidence rate of 8.01 new infections/100 person-years (95% CI: 6.65-9.64); 74% of these participants reported risky injection practices in the past month. In multivariate analysis, moderate-high risk injection behaviors (Adjusted Hazard Ratio [AHR] 2.59; 95% CI 1.45-4.62) were associated with a higher risk of new infections.

CONCLUSIONS

Male IDUs in Delhi continue to practice unsafe injection practices leading to high sero-incidence despite the availability of HIV prevention services offered through targeted intervention programs.

Higher risk of incident hepatitis C virus among young women who inject drugs compared with young men in association with sexual relationships: a prospective analysis from the UFO Study cohort

BACKGROUND

Female injection drug users (IDUs) may report differences in injection behaviours that put them at greater risk for hepatitis C virus (HCV). Few studies have examined these in association with HCV incidence.

METHODS

Longitudinal data from a cohort of 417 HCV-uninfected IDU aged 30 or younger were analysed. Cox proportional hazards was used to model female sex as a predictor of new HCV infection. General estimating equation (GEE) analysis was used to model female sex as a predictor of HCV-associated risk behaviour prospectively.

RESULTS

Women were significantly more likely than men to become infected with HCV during study follow-up (HR 1.4, p<0.05), and were also more likely than men to report high-risk injecting behaviours, especially in the context of sexual and injecting relationships. Sex differences in injecting behaviours appeared to explain the relationship between sex and HCV infection.

CONCLUSIONS

Young women's riskier injection practices lead to their higher rates of HCV infection. Further study on the impact of intimate partnership on women's risk behaviour is warranted.

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.

Risk factors for hepatitis C transmission in HIV patients, Hepacam study, ANRS 12267 Cambodia

In 2009, we conducted a case-control study to explore the routes of HCV transmission in people living with HIV/AIDS (PLHIV) in Cambodia. Cases were HCV/HIV co-infected patients (who tested RT-PCR positive for HCV-RNA or had confirmed presence of HCV antibodies) (n = 44). Controls were HIV mono-infected patients, with no HCV antibodies (n = 160). They were recruited among the PLHIV presenting at one national reference centre of HIV/AIDS. Multivariate analysis showed that factors associated with the co-infection were the age older than 50 years (OR 5.4, 95 % confidence interval (CI) 1.5-19.6), the exposure to multiple parenteral infusions before the year 2000 (OR 3.4, 95 % CI 1.5-7.6), to surgery (OR 2.6, 95 % CI 1.2-5.7) and to fibroscopy (OR 2.4, 95 % CI 1.0-5.7). These results show the need to implement HCV screening in PLHIV, to support the implementation of national infection control guidelines, and to reinforce public awareness on the risks linked to parenteral medications.

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.

High HIV incidence among persons who inject drugs in Pakistan: greater risk with needle sharing and injecting frequently among the homeless

Background

The incidence of HIV among persons who inject drugs (PWIDU) has fallen in many nations, likely due to successes of clean needle/syringe exchange and substance abuse treatment and service programs. However in Pakistan, prevalence rates for PWID have risen dramatically. In several cities, prevalence exceeded 20% by 2009 compared to a 2003 baseline of just 0.5%. However, no cohort study of PWID has ever been conducted.

Methods

We enrolled a cohort of 636 HIV seronegative PWID registered with three drop-in centers that focus on risk reduction and basic social services in Karachi. Recruitment began in 2009 (March to June) and PWID were followed for two years. We measured incidence rates and risk factors associated with HIV seroconversion.

Results

Incidence of HIV was 12.4 per 100 person-years (95% exact Poisson confidence interval [CI]: 10.3–14.9). We followed 474 of 636 HIV seronegative persons (74.5%) for two years, an annual loss to follow-up of <13 per 100 person years. In multivariable Cox regression analysis, HIV seroconversion was associated with non-Muslim religion (Adjusted risk ratio [ARR] = 1.7, 95%CI:1.4, 2.7, p = 0.03), sharing of syringes (ARR = 2.3, 95%CI:1.5, 3.3, p<0.0001), being homeless (ARR = 1.7, 95%CI:1.1, 2.5, p = 0.009), and daily injection of drugs (ARR = 1.1, 95%CI:1.0, 1.3, p = 0.04).

Conclusions

Even though all members of the cohort of PWID were attending risk reduction programs, the HIV incidence rate was very high in Karachi from 2009–2011. The project budget was low, yet we were able to retain three-quarters of the population over two years. Absence of opiate substitution therapy and incomplete needle/syringe exchange coverage undermines success in HIV risk reduction.

Experiences with policing among people who inject drugs in Bangkok, Thailand: a qualitative study

BACKGROUND

Despite Thailand's commitment to treating people who use drugs as "patients" not "criminals," Thai authorities continue to emphasize criminal law enforcement for drug control. In 2003, Thailand's drug war received international criticism due to extensive human rights violations. However, few studies have since investigated the impact of policing on drug-using populations. Therefore, we sought to examine experiences with policing among people who inject drugs (PWID) in Bangkok, Thailand, between 2008 and 2012.

METHODS AND FINDINGS

Between July 2011 and June 2012, semi-structured, in-depth interviews were conducted with 42 community-recruited PWID participating in the Mitsampan Community Research Project in Bangkok. Interviews explored PWID's encounters with police during the past three years. Audio-recorded interviews were transcribed verbatim, and a thematic analysis was conducted to document the character of PWID's experiences with police. Respondents indicated that policing activities had noticeably intensified since rapid urine toxicology screening became available to police. Respondents reported various forms of police misconduct, including false accusations, coercion of confessions, excessive use of force, and extortion of money. However, respondents were reluctant to report misconduct to the authorities in the face of social and structural barriers to seeking justice. Respondents' strategies to avoid police impeded access to health care and facilitated transitions towards the misuse of prescribed pharmaceuticals. The study's limitations relate to the transferability of the findings, including the potential biases associated with the small convenience sample.

CONCLUSIONS

This study suggests that policing in Bangkok has involved injustices, human rights abuses, and corruption, and policing practices in this setting appeared to have increased PWID's vulnerability to poor health through various pathways. Novel to this study are findings pertaining to the use of urine drug testing by police, which highlight the potential for widespread abuse of this emerging technology. These findings raise concern about ongoing policing practices in this setting.

Assisted injection among people who inject drugs in Thailand

Background

Assisted injection is common among people who inject drugs (IDU), and has been associated with elevated risk for HIV infection and overdose. However, this practice has not been explored in the Asian context, including in Thailand, where HIV prevalence among IDU remains high.

Methods

Using multivariate logistic regression, we examined the prevalence and correlates of assisted injecting among IDU participating in the Mitsampan Community Research Project in Bangkok. We also sought to identify reasons for engaging in assisted injecting and those who provide this form of assistance.

Results

In total, 430 IDU participated in this study, including 376 (87.5%) who reported having ever required assistance injecting, and 81 (18.8%) who reported assisted injecting in the previous six months. In multivariate analyses, assisted injecting in the previous six months was independently and positively associated with being female (adjusted odds ratio [AOR] = 2.42; 95% confidence interval [CI]: 1.40 – 4.18), being a weekly heroin injector (AOR = 1.78; 95% CI: 0.99 – 3.20), syringe sharing (AOR = 2.08; 95% CI: 1.18 – 3.68) and soft-tissue infection (AOR = 3.51; 95% CI: 1.43 – 2.53). Having a longer injecting career (AOR = 0.96; 95% CI: 0.94 – 0.99) was negatively associated with assisted injecting. Primary reasons given for engaging in assisted injecting included being new to injecting and lacking knowledge on how to inject. The most common providers of assistance with injecting were close friends.

Conclusion

We found a high prevalence of assisted injecting among IDU in Bangkok, with females, frequent heroin injectors, those with shorter injecting careers being more likely to engage in this practice. Those who require help with the injecting process are more likely to share syringes, and have skin infections. These findings indicate the need for interventions focused on promoting safer and self-administered injections.

High uptake of HIV testing in a cohort of male injection drug users in Delhi, India: prevalence and correlates of HIV infection

We report baseline findings from a longitudinal cohort study to examine HIV incidence, high-risk injection and sexual behaviors of 3,792 male injection drug users (IDUs) in Delhi. The majority (95.4 %) accepted HIV testing; HIV prevalence was 21.9 %. In multivariate analysis, belonging to states adjacent to Delhi (AOR: 1.23; 95 % CI: 1.07-1.52), earning INR 500-1,500 (AOR: 2.38; 95 % CI: 1.43-3.96); duration of drug use 2-5 years (AOR: 2.02; 95 % CI: 1.09-3.73), 6-10 years (AOR: 2.81; 95 % CI: 1.55-5.11), ≥11 years (AOR: 3.35; 95 % CI: 1.84-6.11); prior HIV testing (AOR: 1.60; 95 % CI: 1.35-1.91), self-reported risky-injection behavior (AOR: 1.60; 95 % CI: 1.33-1.92), and utilization of harm-reduction services (AOR: 1.32; 95 % CI: 1.11-1.58) were positively associated with HIV infection. Alcohol use ≤2 times/week (AOR: 0.67; 95 % CI: 0.55-0.82) or ≥3 times/week (AOR: 0.74; 95 % CI: 0.54-1.01), unit increase in age (AOR: 0.99; 95 % CI: 0.98-1.00), ≥7 years of schooling (AOR: 0.82; 95 % CI: 0.66-1.02) and unsafe sex with any female partner (AOR: 0.69; 95 % CI: 0.55-0.86) were negatively associated with HIV infection. HIV prevalence remains high among male IDUs in Delhi. HIV prevention programs should include comprehensive package of services for IDUs.

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.

Baseline findings of an HIV incidence cohort study to prepare for future HIV prevention clinical trials in Kisumu, Kenya

Introduction

In an analysis of baseline findings of an HIV incidence cohort study, an assessment was made of HIV prevalence among persons presenting for enrollment and any differences in demographic characteristics between persons not enrolled compared to those enrolled. We also described and compared HIV risk behaviors in males and females enrolled in the study.

Methodology

A computer-assisted survey was administered to collect baseline demographic and HIV risk data from 1,277 men and women aged 18–34 years. Testing for HIV and other sexually transmitted infections (STI) was conducted. Out of 1,277 persons prescreened for eligibility, 625 were enrolled.

Results

HIV prevalence of all persons who completed screening was 14.8% (females: 21.1%; males: 8.1%). The odds of being enrolled in the study were higher for persons 18–24 years compared to those 30–34 years of age [adjusted odds ratio (AOR)=2.18, CI=1.13, 4.21] and males compared to females [AOR=2.07, CI=1.43, 2.99]. Among those enrolled in the study, the most prevalent HIV risk behaviors were unprotected sex (49%), alcohol use (45%), and transactional sex (30%) in the last three months. Compared to females, a significantly greater proportion of males reported using any alcohol or recreational drug in the last three months, a history of oral sex, sex with partner other than a spouse or main partner, ever having a blood transfusion, ever being treated for an STI, and having knowledge of their last HIV test result.

Conclusion

The Kisumu Field Station successfully recruited individuals with HIV risk characteristics for the HIV incidence cohort study.

Opiate substitution treatment and HIV transmission in people who inject drugs: systematic review and meta-analysis

OBJECTIVE

To quantify the effect of opiate substitution treatment in relation to HIV transmission among people who inject drugs.

DESIGN

Systematic review and meta-analysis of prospective published and unpublished observational studies.

DATA SOURCES

Search of Medline, Embase, PsychINFO, and the Cochrane Library from the earliest year to 2011 without language restriction.

REVIEW METHODS

We selected studies that directly assessed the impact of opiate substitution treatment in relation to incidence of HIV and studies that assessed incidence of HIV in people who inject drugs and that might have collected data regarding exposure to opiate substitution treatment but not have reported it. Authors of these studies were contacted. Data were extracted by two reviewers and pooled in a meta-analysis with a random effects model.

RESULTS

Twelve published studies that examined the impact of opiate substitution treatment on HIV transmission met criteria for inclusion, and unpublished data were obtained from three additional studies. All included studies examined methadone maintenance treatment. Data from nine of these studies could be pooled, including 819 incident HIV infections over 23,608 person years of follow-up. Opiate substitution treatment was associated with a 54% reduction in risk of HIV infection among people who inject drugs (rate ratio 0.46, 95% confidence interval 0.32 to 0.67; P<0.001). There was evidence of heterogeneity between studies (I(2)=60%, χ(2)=20.12, P=0.010), which could not be explained by geographical region, site of recruitment, or the provision of incentives. There was weak evidence for greater benefit associated with longer duration of exposure to opiate substitution treatment.

CONCLUSION

Opiate substitution treatment provided as maintenance therapy is associated with a reduction in the risk of HIV infection among people who inject drugs. These findings, however, could reflect comparatively high levels of motivation to change behaviour and reduce injecting risk behaviour among people who inject drugs who are receiving opiate substitution treatment.

HIV incidence and risk behaviours after voluntary HIV counselling and testing (VCT) among adults aged 19–35 years living in peri-urban communities around Chiang Mai city in northern Thailand, 1999

The Thai government began HIV voluntary counselling and testing (VCT) in all provinces in 1992. We evaluated HIV incidence after participants utilized VCT and its effect on risk behaviours among northern Thai adults aged 19-35 years. A total of 924 men and 1,327 women volunteered to participate in the study. Subjects were counseled, interviewed (socio-demographic, HIV risk behaviour, and HIV testing history), and tested for HIV infection at baseline and at 6 months follow-up. All participants were provided group pre-test counselling; HIV test results were provided in individual confidential post-test counselling. Overall, 329 of 391 men and 621 of 669 women who reported a prior HIV test before participating in our study reported negative results at the previous test. Of these, nine men and 13 women tested positive at baseline, giving incidence rates of 1.04 and 0.69 per 100 person years (PY), respectively. Recent risk behaviour was rare; as a result, the effects of VCT on risk behaviours among the study participants could not be determined. The HIV incidence after VCT among this study population is substantial. Studies to investigate factors associated with HIV incidence among VCT clients could provide insights for more effective HIV prevention.

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.

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

BACKGROUND

Dual infection with diverse HIV strains can foster the emergence of recombinants. The resulting increase in viral genetic diversity is a major challenge for vaccine development HIV treatment. In this study we aim to investigate the socio demographic factors associated with an increasing level of genetic diversity among HIV strains in a population of drug-users in Northern Thailand.

METHODS

From 1999 through 2000, 2231 volunteers were enrolled in the Opiate-Users Research in Chiang Mai, Thailand. HIV subtype analysis was conducted among those HIV-1 seropositive (n=347) using a multi-region hybridization assay. Social and demographic variables were assessed using a structured questionnaire.

RESULTS

Overall, 336/347 (96.8%) of the samples could be typed. 81.8% were CRF01_AE, 3.9% were subtype B, 9.2% were recombinants (mostly between CRF01_AE and B) and 5.1% were dual infections. Dual infections were more frequent among those with a lower education level (AOR: 5.2; 95% CI 1.4-20.3), those who have initiated injecting in the last 3 years (AOR: 3.9; 95% CI 1.1-14.6), and those reporting frequent needle sharing in the last 3 months (AOR: 7.0; 95% CI 1.5-34.1). Both recombinant strains and dual infection were more frequent among those reporting frequent needle sharing in the last 3 months (AOR: 5.3; 95% CI 1.6-17.1).

CONCLUSION

To limit the expanding complexity of HIV-1 strains, early intervention should be aimed at reduction in needle sharing, especially among new intravenous drug users.

Nonparametric inference for competing risks current status data with continuous, discrete or grouped observation times

New methods and theory have recently been developed to nonparametrically estimate cumulative incidence functions for competing risks survival data subject to current status censoring. In particular, the limiting distribution of the nonparametric maximum likelihood estimator and a simplified naive estimator have been established under certain smoothness conditions. In this paper, we establish the large-sample behaviour of these estimators in two additional models, namely when the observation time distribution has discrete support and when the observation times are grouped. These asymptotic results are applied to the construction of confidence intervals in the three different models. The methods are illustrated on two datasets regarding the cumulative incidence of different types of menopause from a cross-sectional sample of women in the United States and subtype-specific HIV infection from a sero-prevalence study in injecting drug users in Thailand.

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.

Assessment of BED HIV-1 incidence assay in seroconverter cohorts: effect of individuals with long-term infection and importance of stable incidence

Background

Performance of the BED assay in estimating HIV-1 incidence has previously been evaluated by using longitudinal specimens from persons with incident HIV infections, but questions remain about its accuracy. We sought to assess its performance in three longitudinal cohorts from Thailand where HIV-1 CRF01_AE and subtype B′ dominate the epidemic.

Design

BED testing was conducted in two longitudinal cohorts with only incident infections (a military conscript cohort and an injection drug user cohort) and in one longitudinal cohort (an HIV-1 vaccine efficacy trial cohort) that also included long-term infections.

Methods

Incidence estimates were generated conventionally (based on the number of annual serocoversions) and by using BED test results in the three cohorts. Adjusted incidence was calculated where appropriate.

Results

For each longitudinal cohort the BED incidence estimates and the conventional incidence estimates were similar when only newly infected persons were tested, whether infected with CRF01_AE or subtype B′. When the analysis included persons with long-term infections (to mimic a true cross-sectional cohort), BED incidence estimates were higher, although not significantly, than the conventional incidence estimates. After adjustment, the BED incidence estimates were closer to the conventional incidence estimates. When the conventional incidence varied over time, as in the early phase of the injection drug user cohort, the difference between the two estimates increased, but not significantly.

Conclusions

Evaluation of the performance of incidence assays requires the inclusion of a substantial number of cohort-derived specimens from individuals with long-term HIV infection and, ideally, the use of cohorts in which incidence remained stable. Appropriate adjustments of the BED incidence estimates generate estimates similar to those generated conventionally.

HIV and hepatitis B and C incidence rates in US correctional populations and high risk groups: a systematic review and meta-analysis

BACKGROUND

High Human Immunodeficiency Virus (HIV) prevalence and high risk behaviors have been well documented within United States (US) correctional systems. However, uncertainty remains regarding the extent to which placing people in prison or jail increases their risk of HIV infection, and regarding which inmate populations experience an increased incidence of HIV. Describing these dynamics more clearly is essential to understanding how inmates and former detainees may be a source for further spread of HIV to the general US population.

METHODS

The authors conducted a systematic review and meta-analysis of studies describing HIV incidence in US correctional facility residents and, for comparison, in high risk groups for HIV infection, such as non-incarcerated intravenous drug users (IVDU) and men who have sex with men (MSM) in the US. HIV incidence rates were further compared with Hepatitis B and Hepatitis C Virus rates in these same populations.

RESULTS

Thirty-six predominantly prospective cohort studies were included. Across all infection outcomes, continuously incarcerated inmates and treatment recruited IVDU showed the lowest incidence, while MSM and street recruited IVDU showed the highest. HIV incidence was highest among inmates released and re-incarcerated. Possible sources of heterogeneity identified among HIV studies were risk population and race.

CONCLUSIONS

Although important literature gaps were found, current evidence suggests that policies and interventions for HIV prevention in correctional populations should prioritize curtailing risk of infection during the post-release period. Future research should evaluate HIV incidence rates in inmate populations, accounting for proportion of high risk sub-groups.

Low incidences of human immunodeficiency virus and hepatitis C virus infection and declining risk behaviors in a cohort of injection drug users in Chennai, India

The authors characterized human immunodeficiency virus (HIV) and hepatitis C virus (HCV) incidence and prospective changes in self-reported risk behavior over 2 years among 1,158 injection drug users (IDUs) recruited in Chennai, India, in 2005-2006. At baseline, HIV prevalence was 25.3%, and HCV prevalence was 54.5%. Seropositive persons with prevalent HIV infection were used to estimate baseline HIV incidence by means of the Calypte HIV-1 BED Incidence EIA (Calypte Biomedical Corporation, Portland, Oregon). Longitudinal HIV and HCV incidence were measured among 865 HIV-negative IDUs and 519 HCV antibody-negative IDUs followed semiannually for 2 years. Participants received pre- and posttest risk reduction counseling at each visit. Estimated HIV incidence at baseline was 2.95 per 100 person-years (95% confidence interval (CI): 1.21, 4.69) by BED assay; observed HIV incidence over 1,262 person-years was 0.48 per 100 person-years (95% CI: 0.17, 1.03). HCV incidence over 645 person-years was 1.71 per 100 person-years (95% CI: 0.85, 3.03). Self-reported risk behaviors declined significantly over time, from 100% of participants reporting drug injection at baseline to 11% at 24 months. In this cohort with high HIV and HCV prevalence at enrollment, the authors observed low incidence and declining self-reported risk behavior over time. While no formal intervention was administered, these findings highlight the potential impact of voluntary counseling and testing in a high-risk cohort.

Prevalence and risk factors for hepatitis C virus infection among young Thai men

Epidemiologic studies of hepatitis C virus (HCV) infection are unusual in developing countries, especially Thailand. We evaluated the prevalence and risk factors for HCV among military conscripts, including a sample of 5,246 men (1:30 sample), and human immunodeficiency virus (HIV)-1 positive men (N = 500) between 2005 and 2008. The HCV prevalence was 2.2% in the sampled group and 8.4% in HIV-1 sero-positives. Among the sampled group, HIV-1 infection, injection drug use (IDU) history, and unsafe injections were associated with HCV infection; adjusted prevalence rate ratios [RRs; 95% confidence intervals (CIs)] were 3.7 (1.04-12.77), 1.9 (1.04-3.54), and 1.8 (1.02-3.11), respectively. Among HIV-1 sero-positives, an IDU history and residence in southern Thailand were associated with HCV prevalence; adjusted RRs (95% CIs) were 3.5 (1.71-7.24) and 2.6 (1.18-5.61), respectively. Public health measures to prevent HCV in Thailand should focus on reducing injection drug use and other exposures to unsafe injections among young Thai men.

Difficulty accessing syringes and syringe borrowing among injection drug users in Bangkok, Thailand

INTRODUCTION AND AIMS

Thailand's longstanding HIV epidemic among injection drug users (IDU) has been attributed, in part, to the Thai government's unwillingness to implement evidence-based HIV prevention interventions. This study was undertaken to examine risk factors for syringe borrowing among a community-recruited sample of Thai IDU.

DESIGN AND METHODS

We examined the prevalence of syringe borrowing among 238 IDU participating in the Mit Sampan Community Research Project, Bangkok. Multivariate logistic regression was used to identify independent predictors of syringe borrowing in the past 6 months.

RESULTS

A total of 238 IDU participated in this study; 66 (26.2%) were female, and the median age was 36.5 years. In total, 72 (30.3%) participants reported borrowing a used syringe in the past 6 months, with 47 (65.3%) of these individuals reporting multiple borrowing events. In multivariate analyses, syringe borrowing was positively associated with difficulty accessing syringes [adjusted odds ratio (AOR) = 2.46; 95% confidence interval (CI): 1.08-5.60] and injecting with other people on a frequent basis (AOR = 3.17; 95% CI: 1.73-5.83). Primary reasons offered for experiencing difficulty accessing syringes included being too far from syringe outlets (34.1%), pharmacies being closed (13.6%) and being refused syringes at pharmacies (9.1%).

DISCUSSION AND CONCLUSIONS

We observed an alarmingly high rate of syringe borrowing among a community-recruited sample of Thai IDU. Various lines of evidence indicate that poor access to sterile syringes is driving the high rate of syringe borrowing observed in this study. Immediate action should be taken to increase access to sterile syringes among Thai IDU.

HIV and risk environment for injecting drug users: the past, present, and future

We systematically reviewed reports about determinants of HIV infection in injecting drug users from 2000 to 2009, classifying findings by type of environmental influence. We then modelled changes in risk environments in regions with severe HIV epidemics associated with injecting drug use. Of 94 studies identified, 25 intentionally examined risk environments. Modelling of HIV epidemics showed substantial heterogeneity in the number of HIV infections that are attributed to injecting drug use and unprotected sex. We estimate that, during 2010-15, HIV prevalence could be reduced by 41% in Odessa (Ukraine), 43% in Karachi (Pakistan), and 30% in Nairobi (Kenya) through a 60% reduction of the unmet need of programmes for opioid substitution, needle exchange, and antiretroviral therapy. Mitigation of patient transition to injecting drugs from non-injecting forms could avert a 98% increase in HIV infections in Karachi; whereas elimination of laws prohibiting opioid substitution with concomitant scale-up could prevent 14% of HIV infections in Nairobi. Optimisation of effectiveness and coverage of interventions is crucial for regions with rapidly growing epidemics. Delineation of environmental risk factors provides a crucial insight into HIV prevention. Evidence-informed, rights-based, combination interventions protecting IDUs' access to HIV prevention and treatment could substantially curtail HIV epidemics.

Overdose experiences among injection drug users in Bangkok, Thailand

Background

Although previous studies have identified high levels of drug-related harm in Thailand, little is known about illicit drug overdose experiences among Thai drug users. We sought to investigate non-fatal overdose experiences and responses to overdose among a community-recruited sample of injection drug users (IDU) in Bangkok, Thailand.

Methods

Data for these analyses came from IDU participating in the Mit Sampan Community Research Project. The primary outcome of interest was a self-reported history of non-fatal overdose. We calculated the prevalence of past overdose and estimated its relationship with individual, drug-using, social, and structural factors using multivariate logistic regression. We also assessed the prevalence of ever witnessing an overdose and patterns of response to overdose.

Results

These analyses included 252 individuals; their median age was 36.5 years (IQR: 29.0 - 44.0) and 66 (26.2%) were female. A history of non-fatal overdose was reported by 75 (29.8%) participants. In a multivariate model, reporting a history of overdose was independently associated with a history of incarceration (Adjusted Odds Ratio [AOR] = 3.83, 95% Confidence Interval [CI]: 1.52 - 9.65, p = 0.004) and reporting use of drugs in combination (AOR = 2.48, 95% CI: 1.16 - 5.33, p = 0.019). A majority (67.9%) reported a history of witnessing an overdose; most reported responding to the most recent overdose using first aid (79.5%).

Conclusions

Experiencing and witnessing an overdose were common in this sample of Thai IDU. These findings support the need for increased provision of evidence-based responses to overdose including peer-based overdose interventions.

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.

Reports of evidence planting by police among a community-based sample of injection drug users in Bangkok, Thailand

Background

Drug policy in Thailand has relied heavily on law enforcement-based approaches. Qualitative reports indicate that police in Thailand have resorted to planting drugs on suspected drug users to extort money or provide grounds for arrest. The present study sought to describe the prevalence and factors associated with this form of evidence planting by police among injection drug users (IDU) in Bangkok.

Methods

Multivariate logistic regression was used to identify factors associated with evidence planting of drugs by police among a community-based sample of IDU in Bangkok. We also examined the prevalence and average amount of money paid by IDU to police in order to avoid arrest.

Results

252 IDU were recruited between July and August, 2008, among whom 66 (26.2%) were female and the median age was 36.5 years. In total, 122 (48.4%) participants reported having drugs planted on them by police. In multivariate analyses, this form of evidence planting was positively associated with midazolam use (Adjusted Odds Ratio [AOR] = 2.84; 95% Confidence Interval [CI]: 1.58 - 5.11), recent non-fatal overdose (AOR = 2.56; 95%CI: 1.40 - 4.66), syringe lending (AOR = 2.08; 95%CI: 1.19 - 3.66), and forced drug treatment (AOR = 1.88; 95%CI: 1.05 - 3.36). Among those who reported having drugs planted on them, 59 (48.3%) paid police a bribe in order to avoid arrest.

Conclusion

A high proportion of community-recruited IDU participating in this study reported having drugs planted on them by police. Drug planting was found to be associated with numerous risk factors including syringe sharing and participation in government-run drug treatment programs. Immediate action should be taken to address this form of abuse of power reportedly used by police.

Mortality among injection drug users in Chennai, India (2005-2008)

BACKGROUND

Injection drug users (IDUs) have estimated mortality rates over 10 times higher than the general population; much of this excess mortality is HIV-associated. Few mortality estimates among IDUs from developing countries, including India, exist.

METHODS

IDUs (1158) were recruited in Chennai from April 2005 to May 2006; 293 were HIV positive. Information on deaths and causes was obtained through outreach workers and family/network members. Mortality rates and standardized mortality ratios were calculated; multivariate Poisson regression was used to identify predictors of mortality.

RESULTS

We observed 85 deaths over 1998 person-years (p-y) of follow-up [mortality rate (MR) 4.25 per 100 p-y; 95% confidence interval (CI) = 3.41-5.23]. The overall standardized mortality ratio was 11.1; for HIV-positive IDUs, the standardized mortality ratio was 23.9. Mortality risk among HIV-positive IDUs (MR: 8.88 per 100 p-y) was nearly three times that of negative IDUs (MR: 3.03 per 100 p-y) and increased with declining immune status (CD4 cells > 350: 5.44 per 100 p-y vs. CD4 cells < or = 200: 34.5 per 100 p-y). This association persisted after adjustment for confounders. The leading causes of mortality in both HIV negative and positive IDUs were overdose (n = 22), AIDS (n = 14), tuberculosis (n = 8) and accident/trauma (n = 9).

CONCLUSION

Substantial mortality was observed in this cohort with the highest rates among HIV-positive IDUs with CD4 counts of less than 350 cells/microl. Although, in these 2 years, non-AIDS deaths outnumbered 0002030-related deaths, the relative contribution of 0002030-associated mortality is likely to increase with advancing HIV disease progression. These data reinforce the need for interventions to reduce the harms associated with drug use and increase HAART access among IDUs in Chennai.

Risks for HIV, HBV, and HCV infections among male injection drug users in northern Vietnam: a case-control study

Injection drug use (IDU) and HIV infection are important public health problems in Vietnam. The IDU population increased 70% from 2000 to 2004 and is disproportionately affected by HIV and AIDS -- the country's second leading cause of death. Hepatitis B virus (HBV) and hepatitis C virus (HCV) share transmission routes with HIV and cause serious medical consequences. This study aimed to determine risk factors for acquisition of HIV, HBV, and HCV infections among IDUs in a northern province. We conducted a matched case-control study among active IDUs aged 18-45 who participated in a community-based survey (30-minute interview and serologic testing). Each HIV-infected IDU (case) was matched with one HIV-uninfected IDU (control) by age, sex (males only), and study site (128 pairs). Similar procedures were used for HBV infection (50 pairs) and HCV infection (65 pairs). Conditional logistic regression models were fit to identify risk factors for each infection. Among 309 surveyed IDUs, the HIV, HBV, and HCV prevalence was 42.4%, 80.9%, and 74.1%, respectively. Only 11.0% reported having been vaccinated against hepatitis B. While 13.3% of the IDUs reported sharing needles (past six months), 63.8% engaged in indirect sharing practices (past six months), including sharing drug solutions, containers, rinse water, and frontloading drugs. In multivariable models, sharing drugs through frontloading was significantly associated with HIV infection (odds ratio [OR]=2.8), HBV infection (OR=3.8), and HCV infection (OR=4.6). We report an unrecognized association between sharing drugs through frontloading and higher rates of HIV, HBV and HCV infections among male IDUs in Vietnam. This finding may have important implications for bloodborne viral prevention for IDUs in Vietnam.

A qualitative inquiry into methadone maintenance treatment for opioid-dependent prisoners in Tehran, Iran

BACKGROUND

This study aimed to investigate the context in which methadone maintenance treatment (MMT) is provided for opioid-dependent prisoners, and to identify barriers against further scale-up of MMT in Ghezel Hesar prison in Tehran.

METHODS

This was a cross-sectional qualitative study using field observations, focus group discussions, and individual interviews. In total, 30 prisoners and 15 prison staff and health policymakers participated in this study in November 2006.

RESULTS

The rate of drug injecting in the prison unit was unanimously reported to have decreased drastically since introducing the MMT program. In addition to the health benefits to MMT recipients, interview data indicates that MMT has had positive effects on socio-economic status of prisoners' families. Nevertheless, several impediments to the provision of MMT services and to its further expansion were also identified, including staff shortages, some degree of methadone diversion, widespread concerns over the possible side effects of methadone, and the stigma attached to methadone treatment.

CONCLUSION

MMT constitutes one of the main components of the Iran Prison Organization's comprehensive HIV prevention package and is becoming increasingly accessible to opioid-dependent prisoners in Iran. Our findings indicate that the MMT program in Ghezel Hesar prison has been helpful for many opioid-dependent prisoners to reduce their risk of drug-related harm and to ease social and financial burden over their families. Meanwhile, existing barriers against provision of MMT should be properly addressed before further scale up of the program.