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1.  In Peru, reporting male sex partners imparts significant risk of incident HIV/STI infection: all men engaging in same-sex behavior need prevention services 
Sexually transmitted diseases  2013;40(7):569-574.
Detailed information on the sexual behavior of bisexual, non-gay identified men and the relationship between same-sex behavior and HIV/STI incidence are limited. This study provides information on the sexual behavior with male partners of non-gay identified men in urban, coastal Peru and the relationship of this behavior with HIV/STI incidence.
We analyzed data from 2146 non-gay identified men with a baseline and then two years of annual follow-up, including detailed information on sexual behavior with up to 5 sex partners, to determine characteristics associated with bisexual behavior. Discrete time proportional hazards models were used to determine the effect of self-reported sex with men on subsequent HIV/STI incidence.
Over the three study visits, sex with a man was reported by 18.9% of men, 90% of whom also reported sex with a female partner. At baseline, reported bisexual behavior was associated with other sexual risk behaviors such as exchanging sex for money and increased risk of HIV, HSV-2, and gonorrhea. The number of study visits in which recent sex with men was reported was positively correlated with risk of other sexual risk behaviors and incident HIV, HSV-2, and gonorrhea. Recent sex with a man was associated with increased HIV/STI incidence, HR 1.79 (95% CI 1.19 – 2.70), after adjusting for socio-demographics and other sexual risk behaviors.
Given the prevalence of recent sex with men and the relationship of this behavior with HIV/STI incidence, interventions with non-gay identified men who have sex with men and their partners are warranted.
PMCID: PMC3752699  PMID: 23965772
Bisexual men; Men who have sex with men; sexual risk behavior; HIV/STI prevention; Peru
2.  A comparison of HIV/AIDS-related stigma in four countries: Negative attitudes and perceived acts of discrimination towards people living with HIV/AIDS☆ 
Social science & medicine (1982)  2009;68(12):2279-2287.
HIV/AIDS-related stigma and discrimination have a substantial impact on people living with HIV/AIDS (PLHA). The objectives of this study were: (1) to determine the associations of two constructs of HIV/AIDS-related stigma and discrimination (negative attitudes towards PLHA and perceived acts of discrimination towards PLHA) with previous history of HIV testing, knowledge of antiretroviral therapies (ARVs) and communication regarding HIV/AIDS and (2) to compare these two constructs across the five research sites with respect to differing levels of HIV prevalence and ARV coverage, using data presented from the baseline survey of U.S. National Institute of Mental Health (NIMH) Project Accept, a four-country HIV prevention trial in Sub-Saharan Africa (Tanzania, Zimbabwe and South Africa) and northern Thailand. A household probability sample of 14,203 participants completed a survey including a scale measuring HIV/AIDS-related stigma and discrimination. Logistic regression models determined the associations between negative attitudes and perceived discrimination with individual history of HIV testing, knowledge of ARVs and communication regarding HIV/AIDS. Spearman's correlation coefficients determined the relationships between negative attitudes and perceived discrimination and HIV prevalence and ARV coverage at the site-level. Negative attitudes were related to never having tested for HIV, lacking knowledge of ARVs, and never having discussed HIV/AIDS. More negative attitudes were found in sites with the lowest HIV prevalence (i.e., Tanzania and Thailand) and more perceived discrimination against PLHA was found in sites with the lowest ARV coverage (i.e., Tanzania and Zimbabwe). Programs that promote widespread HIV testing and discussion of HIV/AIDS, as well as education regarding and universal access to ARVs, may reduce HIV/AIDS-related stigma and discrimination.
PMCID: PMC4029331  PMID: 19427086
Sub-Saharan Africa; Thailand; HIV/AIDS; Stigma; Discrimination; Tanzania; Zimbabwe; South Africa
3.  Prevalence and Seroincidence of Hepatitis B and Hepatitis C Infection in High Risk People Who Inject Drugs in China and Thailand 
We determined the prevalence and incidence of HBV and HCV infection in people who inject drugs (PWIDs) at high risk for HIV in China and Thailand and determined the association of HBV and HCV incidence with urine opiate test results and with short-term versus long-term buprenorphine-naloxone (B-N) treatment use in a randomized clinical trial (HPTN 058). 13.8% of 1049 PWIDs in China and 13.9% of 201 PWIDs in Thailand were HBsAg positive at baseline. Among HBsAg negative participants, the HBsAg incidence rate was 2.7/100 person years in China and 0/100 person years in Thailand. 81.9% of 1049 PWIDs in China and 59.7% of 201 in Thailand were HCV antibody positive at baseline. The HCV confirmed seroincidence rate among HCV antibody negative PWIDs was 22/100 person years in China and 4.6/100 person years in Thailand. Incident HBsAg was not significantly different in the short-term versus long-term B-N arm in China or Thailand. Participants with positive opiate results in at least 75% of their urines during the time period were at increased risk of incident HBsAg (HR = 5.22; 95% CI, 1.08 to 25.22; P = 0.04) in China, but not incident HCV conversion in China or Thailand.
PMCID: PMC3985324  PMID: 24860664
4.  Sexually transmitted infection risk behaviors in rural Thai adolescents and young adults: Support for gender- and age-specific interventions 
Sexually transmitted diseases  2013;40(3):216-220.
STI prevalence and risks in a sample of rural Thai adolescents and young adults (14–29 years old) were examined. Unprotected sex with a casual partner conferred the greatest risk for prevalent STIs, particularly for younger adolescents and alcohol use increased the STI risk for women but not for men.
PMCID: PMC3572507  PMID: 23403603
Thailand; adolescents; sexually transmitted infections; gender; social norms
5.  Effects of an HIV peer prevention intervention on sexual and injecting risk behaviors among injecting drug users and their risk partners in Thai Nguyen, Vietnam: A randomized controlled trial 
Globally, 30% of new HIV infections outside sub-Saharan Africa involve injecting drug users (IDU) and in many countries, including Vietnam, HIV epidemics are concentrated among IDU. We conducted a randomized controlled trial in Thai Nguyen, Vietnam, to evaluate whether a peer oriented behavioral intervention could reduce injecting and sexual HIV risk behaviors among IDU and their network members. 419 HIV-negative index IDU aged 18 years or older and 516 injecting and sexual network members were enrolled. Each index participant was randomly assigned to receive a series of six small group peer educator-training sessions and three booster sessions in addition to HIV testing and counseling (HTC) (intervention; n = 210) or HTC only (control; n = 209). Follow-up, including HTC, was conducted at 3, 6, 9 and 12 months post-intervention. The proportion of unprotected sex dropped significantly from 49% to 27% (SE (difference) = 3%, p < 0.01) between baseline and the 3-month visit among all index-network member pairs. However, at 12 months, post-intervention, intervention participants had a 14% greater decline in unprotected sex relative to control participants (Wald test = 10.8, df = 4, p = 0.03). This intervention effect is explained by trial participants assigned to the control arm who missed at least one standardized HTC session during follow-up and subsequently reported increased unprotected sex. The proportion of observed needle/syringe sharing dropped significantly between baseline and the 3-month visit (14% vs. 3%, SE (difference) = 2%, p < 0.01) and persisted until 12 months, but there was no difference across trial arms (Wald test = 3.74, df = 3, p = 0.44).
PMCID: PMC3938286  PMID: 24034963
Vietnam; Injecting drug use; HIV; Randomized controlled trial; Peer network; Intervention; Evaluation
6.  Elevated alcohol and sexual risk behaviors among young Thai lesbian/bisexual women 
Drug and alcohol dependence  2012;127(1-3):53-58.
Little empirical data have been published about drinking or sexual behaviors among Thai lesbians. We examine the association of sexual identity with established indicators of alcohol- and sexual-related health behaviors among female bar patrons.
We conducted a cross-sectional study among women (N=121) aged 18–24 who frequented popular drinking establishments in Chiang Mai, Thailand. We used general linear modeling techniques to estimate associations between sexual identity and positive alcohol expectancy, harmful drinking, age at sexual debut, and number of lifetime sexual partners.
Nearly one-third of women aged 18–24 recruited from Chiang Mai drinking venues identified as lesbian/bisexual. As compared to their heterosexual counterparts, lesbian/bisexuals reported higher positive alcohol expectancy scores, more harmful drinking, earlier age at sexual debut, and higher number of lifetime sexual partners. In adjusted models, lesbian/bisexual identity was associated with higher positive alcohol expectancy (β=1.94 points; 95% CI: 0.75,3.13), earlier age at sexual debut (β = −0.85 years; 95% CI:−1.46,−0.23), and higher number of lifetime sexual partners (Rate Ratio=1.7; 95% CI:1.22, 2.37).
Lesbian/bisexual women in this study engaged in multiple behaviors that are potentially harmful to health, which may in turn place this group at heightened risk for alcohol abuse and sexually transmitted infections in Thailand. The clustering of alcohol- and sexual-related risk behaviors, and its consequences for health outcomes in this population, should be explored in future research and may be an important point of intervention.
PMCID: PMC3486947  PMID: 22770462
Lesbian health; Adolescent women; Alcohol use; Sexual health risk; Thailand
7.  Changes in sexual and drug-related risk behavior following antiretroviral therapy initiation among HIV-infected injection drug users 
AIDS (London, England)  2012;26(18):2383-2391.
To evaluate whether HAART is associated with subsequent sexual and drug-related risk behavior compensation among injection drug users (IDUs).
A community-based cohort study of 362 HIV-infected IDUs initiating HAART in Baltimore, Maryland.
HAART use and risk behavior was assessed at 8316 biannual study visits (median 23). Using logistic regression with generalized estimating equations (GEE), we examined the effect of HAART initiation on changes in risk behavior while adjusting for sociodemographics, alcohol use, CD4+ cell count, year of initiation and consistency of HAART use.
At HAART initiation, participants were a median of 44.4 years old, 71.3% men and 95.3% African–American. In multivariable analysis, HAART initiation was associated with a 75% reduction in the likelihood of unprotected sex [adjusted odds ratio (aOR) 0.25; 95% confidence interval (CI), 0.19–0.32] despite no change in overall sexual activity (aOR 0.95; 0.80–1.12). Odds of any injecting decreased by 38% (aOR 0.62; 0.51–0.75) after HAART initiation. Among the subset of persistent injectors, needle-sharing increased nearly two-fold (aOR 1.99; 1.57–2.52). Behavioral changes were sustained for more than 5 years after HAART initiation and did not differ by consistency of HAART use. Reporting specific high-risk behaviors in the year prior to initiation was a robust predictor of engaging in those behaviors subsequent to HAART.
Overall, substantial declines in sexual risk-taking and active injecting argue against significant behavioral compensation among IDUs following HAART initiation. These data also provide evidence to support identifying persons with risky pre-HAART behavior for targeted behavioral intervention.
PMCID: PMC3678983  PMID: 23079804
antiretroviral therapy; HIV prevention; injecting; injection drug users; risk compensation; sexual behavior
8.  The association between cervical HPV infection and HIV acquisition among women in Zimbabwe 
AIDS (London, England)  2010;24(7):1035-1042.
The prevalence of HPV is higher among HIV+ women, but the prevalence of HPV prior to HIV acquisition has not been carefully evaluated.
This study evaluated whether HPV infection is independently associated with heterosexual HIV acquisition in a cohort of Zimbabwean women.
Case-control study nested within a large multi-center cohort study (HC-HIV).
Cases consisted of Zimbabwean women with incident HIV infection observed during follow-up (n=145). HIV-uninfected controls were selected and matched to cases (n=446). The prevalence of cervical HPV infections was compared at the visit prior to HIV infection in the cases and at the same follow-up visit in the matched controls.
The odds of acquiring HIV were 2.4 times higher in women with prior cervical HPV infection after adjustment for behavioral and biologic risk factors. There was no statistically significant difference in the risk of HIV acquisition between women infected with high versus low risk HPV types. Loss of detection of at least one HPV DNA type was significantly associated with HIV acquisition (OR =5.4 [95%CI, 2.9–9.9] (p<.0001).
Cervical HPV infection is associated with HIV acquisition among women residing in a region with a high prevalence of both infections. Further studies are required to evaluate whether the observed association is causal.
PMCID: PMC3831602  PMID: 20397287
HPV; heterosexual HIV transmission; HIV prevention; cervical HPV; STI
9.  HIV among People Who Inject Drugs in the Middle East and North Africa: Systematic Review and Data Synthesis 
PLoS Medicine  2014;11(6):e1001663.
Laith Abu-Raddad and colleagues assess the current state of knowledge of the HIV epidemic among people who inject drugs in the Middle East and North Africa.
Please see later in the article for the Editors' Summary
It is perceived that little is known about the epidemiology of HIV infection among people who inject drugs (PWID) in the Middle East and North Africa (MENA). The primary objective of this study was to assess the status of the HIV epidemic among PWID in MENA by describing HIV prevalence and incidence. Secondary objectives were to describe the risk behavior environment and the HIV epidemic potential among PWID, and to estimate the prevalence of injecting drug use in MENA.
Methods and Findings
This was a systematic review following the PRISMA guidelines and covering 23 MENA countries. PubMed, Embase, regional and international databases, as well as country-level reports were searched up to December 16, 2013. Primary studies reporting (1) the prevalence/incidence of HIV, other sexually transmitted infections, or hepatitis C virus (HCV) among PWIDs; or (2) the prevalence of injecting or sexual risk behaviors, or HIV knowledge among PWID; or (3) the number/proportion of PWID in MENA countries, were eligible for inclusion. The quality, quantity, and geographic coverage of the data were assessed at country level. Risk of bias in predefined quality domains was described to assess the quality of available HIV prevalence measures. After multiple level screening, 192 eligible reports were included in the review. There were 197 HIV prevalence measures on a total of 58,241 PWID extracted from reports, and an additional 226 HIV prevalence measures extracted from the databases.
We estimated that there are 626,000 PWID in MENA (range: 335,000–1,635,000, prevalence of 0.24 per 100 adults). We found evidence of HIV epidemics among PWID in at least one-third of MENA countries, most of which are emerging concentrated epidemics and with HIV prevalence overall in the range of 10%–15%. Some of the epidemics have however already reached considerable levels including some of the highest HIV prevalence among PWID globally (87.1% in Tripoli, Libya). The relatively high prevalence of sharing needles/syringes (18%–28% in the last injection), the low levels of condom use (20%–54% ever condom use), the high levels of having sex with sex workers and of men having sex with men (15%–30% and 2%–10% in the last year, respectively), and of selling sex (5%–29% in the last year), indicate a high injecting and sexual risk environment. The prevalence of HCV (31%–64%) and of sexually transmitted infections suggest high levels of risk behavior indicative of the potential for more and larger HIV epidemics.
Our study identified a large volume of HIV-related biological and behavioral data among PWID in the MENA region. The coverage and quality of the data varied between countries. There is robust evidence for HIV epidemics among PWID in multiple countries, most of which have emerged within the last decade and continue to grow. The lack of sufficient evidence in some MENA countries does not preclude the possibility of hidden epidemics among PWID in these settings. With the HIV epidemic among PWID in overall a relatively early phase, there is a window of opportunity for prevention that should not be missed through the provision of comprehensive programs, including scale-up of harm reduction services and expansion of surveillance systems.
Please see later in the article for the Editors' Summary
Editors' Summary
About 35 million people worldwide are currently infected with HIV, the virus that causes AIDS, and around 2.3 million people become newly infected every year. HIV is mainly transmitted through unprotected sex with an infected partner. However, people who inject drugs (PWID) have a particularly high risk of HIV infection because blood transfer through needle and syringe sharing can transmit the virus. Worldwide, 5%–10% of all HIV-positive people are PWID but in some regions of the world the fraction of all HIV-positive people that are PWID is even higher. To meet the global health challenge of the high HIV prevalence (the proportion of a population that has a specific disease) among PWID, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and other international bodies endorse harm reduction strategies to prevent risky injection behaviors among PWID. These strategies include education and the provision of clean needles, syringes, and opioid substitution therapy.
Why Was This Study Done?
To maximize the effect of these harm-reduction strategies in specific regions, it is important to understand the status of the HIV epidemic among PWID. Although surveillance systems provide the information on HIV infection needed to track the progress of HIV epidemics among PWID in many regions, little is known about the HIV epidemic among PWID in the Middle East and North Africa (MENA, a geographical region that encompasses countries that share historical, socio-cultural, linguistic, and religious characteristics). Several factors contribute to the likelihood of individuals injecting drugs in MENA. For example, Afghanistan (a MENA country) produces most of the world's supply of heroin, which is largely trafficked through Iran and Pakistan (also MENA countries). In this systematic review and data synthesis, the researchers use predefined criteria to identify all the published and unpublished data on HIV prevalence and incidence (the number of new cases of a disease in a population in a given time) among PWID in MENA and combine (synthesize) these data to assess the status of the HIV epidemic in this key population for HIV transmission in MENA.
What Did the Researchers Do and Find?
The researchers identified 192 reports that reported the prevalence/incidence of HIV, other sexually transmitted infections and infection with hepatitis C virus (HCV, another virus transmitted through drug injection) among PWID, the prevalence of injecting or sexual risk behaviors among PWID, or the number/proportion of PWID in MENA. From these data, the researchers estimated that there are about 600,000 PWID in MENA (a prevalence of 0.24 per 100 adults, which is comparable with figures from other regions). The data provided evidence for HIV epidemics among PWID in at least a third of MENA countries, mainly emerging concentrated epidemics (epidemics that are still growing but in which HIV infection and transmission are already considerable). HIV prevalence among PWID in MENA varied considerably, reaching an extremely high prevalence of 87.1% in Tripoli, Libya. The data also revealed a high injecting and sexual risk environment among PWID in MENA (for example, on average, about a quarter of PWID shared a needle or syringe in their most recent injection and only a third reported ever using condoms) that, together with a high prevalence of HCV and sexually transmitted infections among PWID, indicates the potential for more and larger HIV epidemics.
What Do These Findings Mean?
These findings indicate that substantial amounts of HIV-related data have been collected from PWID in MENA but that the coverage and quality of these data vary widely between countries. They provide robust evidence for growing HIV epidemics, most of which have emerged within the past decade, among PWID in several MENA countries, but do not preclude the possibility of hidden epidemics among PWID in additional MENA countries. Overall, these findings suggest that the HIV epidemic among PWID in MENA is at a relatively early stage. This window of opportunity to control the emerging epidemics should not be missed, warn the researchers. HIV surveillance among PWID in MENA must be expanded to detect and monitor emerging and growing HIV epidemics, they suggest, and to inform effective HIV policy and programming. Improvements in HIV prevention and treatment among PWID in MENA are essential, they conclude, to confront the growing HIV problem in this population and, to prevent the onward transmission of HIV from PWID to other population groups.
Additional Information
Please access these websites via the online version of this summary at
A 2010 report produced by the World Bank, UNAIDS, and WHO provides information on the status of the HIV epidemic in the Middle East and North Africa; the UNAIDS Middle East and North Africa Regional Report on AIDS 2011 provides further information
The 2013 UNAIDS World AIDS Day Report provides up-to-date information about the AIDS epidemic and efforts to halt it
The Middle East and North Africa Harm Reduction Association (MENAHRA) provides information about harm reduction efforts, services, and programs in the Middle East and North Africa; Harm Reduction International provides information about harm reduction concepts, strategies, programs, and publications globally
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
NAM/aidsmap provides basic information about HIV/AIDS, and summaries of recent research findings on HIV care and treatment
Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on people who inject drugs and HIV/AIDS and on harm reduction and HIV prevention (in English and Spanish)
The US National Institute on Drug Abuse also provides information about drug abuse and HIV/AIDS (in English and Spanish)
Personal stories about living with HIV/AIDS are available through Avert, Nam/aidsmap, and Healthtalkonline
PMCID: PMC4061009  PMID: 24937136
10.  Incidence of HIV and Sexually Transmitted Infections and Risk Factors for Acquisition among Young Methamphetamine Users in Northern Thailand 
Sexually transmitted diseases  2009;36(5):284-289.
Southeast Asia is experiencing an epidemic of methamphetamine use, a drug associated with risky sexual behaviors, putting a large segment of the population at increased risk for STI and HIV and in need of prevention efforts. Incidence estimates of sexually transmitted infections (STIs) are rare in Southeast Asia, especially among newer risk groups.
Study Design
We enrolled methamphetamine users aged 18 to 25 years in a 12-month randomized behavioral intervention trial in Chiang Mai, Thailand in 2005. Behavioral questionnaires were administered at visits every three months and biological specimens were collected at baseline and 12 months to test for common STIs (chlamydia, gonorrhea, HSV-2, and HIV). Poisson regression with robust variance was used to determine risk factors for incident STIs.
Overall, 12.7% of 519 participants acquired at least one STI. Chlamydia was the most common (10.6%), followed by HSV-2 (4.0%), gonorrhea (2.9%), and HIV (0.6%). Risk factors for both men and women included self-reported incarceration and having a casual sex partner during follow-up, and having a prevalent STI at baseline. Additionally, among women, having 2 or more heterosexual partners, and among men, having a greater frequency of drunkenness were risk factors for STI acquisition.
While HIV incidence is low in this population, incidence of other STIs is high compared to previous studies of young Thai adults. Risk factors for acquisition emphasize the need for new prevention strategies targeted towards current populations at risk.
PMCID: PMC3682416  PMID: 19295472
Thailand; HIV; STI; methamphetamine; young adults
11.  Short-term safety of buprenorphine/naloxone in HIV-seronegative opioid-dependent Chinese and Thai drug injectors enrolled in HIV Prevention Trials Network 058 
Buprenorphine/naloxone (BUP/NX) is not licensed for use in China or Thailand and there was little clinical experience with this drug combination in these countries at the inception of HIV Prevention Trial Network (HPTN) 058, a randomized trial comparing risk reduction counseling combined with either short-term or long-term medication assisted treatment with BUP/NX to prevent HIV infection and death among opioid-dependent injectors.
We conducted a safety phase that included the first 50 subjects enrolled at each of the three initial study sites (N=150). Clinical and laboratory assessments were conducted at baseline and weekly for the first 4 weeks. Changes in laboratory parameters were estimated with random effects models.
BUP/NX was well tolerated by study subjects and opioid withdrawal scores decreased substantially during the 3-day induction. Two participants experienced grade 3 clinical adverse events, which were categorized as probably not related to the study drug. Grade 2 or 3 increases in alanine aminotransferase (ALT) occurred in 25 (17%) subjects. The magnitude of ALT increase over 4-week follow-up was strongly associated with baseline ALT elevation.
In Chinese and Thai opioid-dependent injectors, we found BUP/NX to be effective in reducing opioid withdrawal symptoms and safe during short-term use. ALT increases were observed over 4-week-follow-up, which are consistent with reports from Western populations. Long-term safety and efficacy evaluations are indicated.
PMCID: PMC3236277  PMID: 21852093
buprenorphine/naloxone; injection drug use; opioid dependence; HIV prevention; risk reduction counseling; safety; hepatic toxicity
12.  Quality of Life Among Individuals with HIV Starting Antiretroviral Therapy in Diverse Resource-Limited Areas of the World 
AIDS and Behavior  2012;16(2):266-277.
As Antiretroviral Therapy (ART) is scaled up in low- and middle-income countries, it is important to understand Quality of Life (QOL) correlates including disease severity and person characteristics and to determine the extent of between-country differences among those with HIV. QOL and medical data were collected from 1,563 of the 1,571 participants at entry into a randomized clinical trial of ART conducted in the U.S. (n = 203) and 8 resource-limited countries (n = 1,360) in the Caribbean, South America, Asia, and Africa. Participants were interviewed prior to initiation of ART using a modified version of the ACTG SF-21, a health-related QOL measure including 8 subscales: general health perception, physical functioning, role functioning, social functioning, cognitive functioning, pain, mental health, and energy/fatigue. Other measures included demographics, CD4+ lymphocyte count, plasma HIV-1 RNA viral load. Higher quality of life in each of the 8 QOL subscales was associated with higher CD4+ lymphocyte category. General health perception, physical functioning, role functioning, and energy/fatigue varied by plasma HIV-1 RNA viral load categories. Each QOL subscale included significant variation by country. Only the social functioning subscale varied by sex, with men having greater impairments than women, and only the physical functioning subscale varied by age category. This was the first large-scale international ART trial to conduct a standardized assessment of QOL in diverse international settings, thus demonstrating that implementation of the behavioral assessment was feasible. QOL indicators at study entry varied with disease severity, demographics, and country. The relationship of these measures to treatment outcomes can and should be examined in clinical trials of ART in resource-limited settings using similar methodologies.
PMCID: PMC3182285  PMID: 21499794
Quality of life (QOL); Highly active antiretroviral therapy (HAART); HIV
13.  Factors associated with injection cessation, relapse and initiation in a community-based cohort of injection drug users in Chennai, India 
Addiction (Abingdon, England)  2011;107(2):349-358.
To characterize factors associated with injection cessation, relapse and initiation.
MIDACS is a prospective cohort of injection drug users (IDUs) recruited in 2005–06 with semi-annual follow-up through 2009. Discrete-time survival models were used to characterize predictors of time to first injection cessation and relapse.
Chennai, India
855 IDUs who reported injecting in the six months prior to baseline and had > 1 follow-up visit.
Cessation was defined as the first visit where no injection drug use was reported (prior six months) and relapse as the first visit where drug injection (prior six months) was reported after first cessation.
All participants were male; median age was 35. Over three years, 92.7% reported cessation (incidence rate [IR]: 117 per 100 person-years). Factors positively associated with cessation included daily injection and incarceration and factors negatively associated with cessation included marriage, alcohol and homelessness. Of those who reported cessation, 24% relapsed (IR: 19.7 per 100 person-years). Factors positively associated with relapse included any education, injection in the month prior to baseline, sex with a casual partner, non-injection drug use, incarceration and homelessness. Alcohol was negatively associated with relapse. The primary reasons for cessation were medical conditions (36%) and family pressure (22%). The majority initiated with non-injection drugs, transitioning to injection after a median 4 years.
Injection drug users in Southern India demonstrate a high rate of injection cessation over three years, but relapse is not uncommon. Compensatory increases in alcohol use indicate that cessation of injection does not mean cessation of all substance use. Family pressure, concerns about general health, fear of HIV infection, and a history of non-injection drug use are important correlates of cessation.
PMCID: PMC3222716  PMID: 21815960
natural history; drug use; India; injection drug users; cohort
14.  Combined Oral Contraceptive Use Increases HPV Persistence but Not New HPV Detection in a Cohort of Women From Thailand 
The Journal of Infectious Diseases  2011;204(10):1505-1513.
Background. Women diagnosed with cervical cancer report longer duration and more recent use of combined oral contraceptives (COCs). It is unclear how COC use impacts risk of cervical carcinogenesis.
Methods. We estimated the risk of new human papillomavirus (HPV) DNA detection and persistence among 1135 human immunodeficiency virus (HIV)–negative women aged 20–37 years from Thailand who were followed for 18 months at 6-month intervals. Type-specific HPV DNA, demographic information, hormonal contraceptive use, sexual behavior, genital tract coinfection, and Papanicolaou test results were assessed at baseline and each follow-up.
Results. Women who reported current COC use during follow-up were less likely to clear HPV infection compared with nonusers, independent of sexual behavior, and Papanicolaou test diagnosis (AHR: 0.67 [95% CI: .49–.93]). Similar associations were not observed among women reporting current use of depomedroxyprogesterone acetate (DMPA). Neither COC nor DMPA use was significantly associated with new HPV DNA detection.
Conclusions. These data do not support the hypothesis that contraceptive use is associated with cervical cancer risk via increased risk of HPV acquisition. The increased risk of HPV persistence observed among current COC users suggests a possible influence of female sex hormones on host response to HPV infection.
PMCID: PMC3222104  PMID: 21964399
15.  The Effect of Neighborhood Deprivation and Residential Relocation on Long-term Injection Cessation among Injection Drug Users (IDUs) in Baltimore, Maryland 
Addiction (Abingdon, England)  2011;106(11):1966-1974.
To determine the incidence of long-term injection cessation and its association with residential relocation and neighborhood deprivation.
ALIVE (AIDS Linked to the Intravenous Experience) is a prospective cohort with semi-annual follow-up since 1988. Multi-level discrete time-to-event models were constructed to investigate individual and neighborhood-level predictors of long-term injection cessation.
Baltimore, USA
1,697 active injectors from ALIVE with at least 8 semi-annual study visits.
Long-term injection cessation was defined as three consecutive years without self-reported injection drug use.
706 (42%) injectors achieved long-term cessation (incidence = 7.6 per 100 person-years). After adjusting for individual-level factors, long-term injection cessation was 29% less likely in neighborhoods in the third quartile of deprivation (Hazard Ratio [HR] =0.71, 95% CI:0.53–0.95) and 43% less likely in the highest quartile of deprivation (HR=0.57, 95% CI:0.43, 0.76) as compared to the first quartile. Residential relocation was associated with increased likelihood of long-term injection cessation (HR=1.55, 95% CI:1.31, 1.82); however the impact of relocation varied depending on the deprivation in the destination neighborhood. Compared to those who stayed in less deprived neighborhoods, relocation from highly deprived to less deprived neighborhoods had the strongest positive impact on long-term injection cessation (HR=1.96, 95% CI:1.50, 2.57), while staying in the most deprived neighborhoods was detrimental (HR=0.76, 95% CI:0.63, 0.93).
Long-term cessation of injection of opiates and cocaine occurred frequently following a median of 9 years of injection and contextual factors appear to be important. Our findings suggest that improvements in the socio-economic environment may improve the effectiveness of cessation programs.
PMCID: PMC3189272  PMID: 21592251
16.  Validation Data-Based Adjustments for Outcome Misclassification in Logistic Regression:An Illustration 
Epidemiology (Cambridge, Mass.)  2011;22(4):589-597.
Misclassification of binary outcome variables is a known source of potentially serious bias when estimating adjusted odds ratios. Although researchers have described frequentist and Bayesian methods for dealing with the problem, these methods have seldom fully bridged the gap between statistical research and epidemiologic practice. In particular, there have been few real-world applications of readily grasped and computationally accessible methods that make direct use of internal validation data to adjust for differential outcome misclassification in logistic regression. In this paper, we illustrate likelihood-based methods for this purpose that can be implemented using standard statistical software. Using main study and internal validation data from the HIV Epidemiology Research Study, we demonstrate how misclassification rates can depend on the values of subject-specific covariates, and illustrate the importance of accounting for this dependence. Simulation studies confirm the effectiveness of the maximum likelihood approach. We emphasize clear exposition of the likelihood function itself, to permit the reader to easily assimilate appended computer code that facilitates sensitivity analyses as well as the efficient handling of main/external and main/internal validation-study data. These methods are readily applicable under random cross-sectional sampling, and we discuss the extent to which the main/internal analysis remains appropriate under outcome-dependent (case-control) sampling.
PMCID: PMC3454464  PMID: 21487295
17.  Variations in sexual risks in drug users: Emerging themes in a behavioral context 
Current HIV/AIDS reports  2008;5(4):212-218.
Drug users are an especially complex population among those studied in HIV-risk behavior research. While injection drug use accounts for over one-third of cumulative HIV transmission in the U.S., the scope of the direct and indirect impact of all drug use is difficult to quantify, especially in relation to attributing HIV to either drug use directly via parenteral exposures or indirectly, through unsafe sex. Important behavioral issues such as social and drug network overlaps, partner selection and the combinations of illicit drugs with erectile dysfunction medications have added complexity to the studying of sexual behavior in drug users. This review covers recent substantive research in the U.S. and Canada on current themes in sexual risk behavior in injection drug and non-injection drug users. We address gender, situational and sexual preference factors that may influence sexual behaviors affecting HIV risk by class of drug and route of administration. Special attention is paid to minority populations, both sexual and race/ethnicity, as their marginalized role in contemporary society places special barriers for risk reduction.
PMCID: PMC2801160  PMID: 18838061
18.  HIV Risk Behaviors in Sub-Saharan Africa and Northern Thailand: Baseline Behavioral Data from Project Accept 
Of 2.5 million new HIV infections worldwide in 2007, most occurred in Sub-Saharan Africa and Southeast Asia. We present the baseline data on HIV risk behaviors and HIV testing in Sub-Saharan Africa and northern Thailand from Project Accept, a community-randomized controlled trial of community mobilization, mobile voluntary counseling and testing (VCT), and post-test support services.
A random household probability sample of individuals aged 18–32 years yielded a sample of 14,657 with response rates ranging from 84–94% across the five sites (Thailand, Zimbabwe, Tanzania and two in South Africa). Individuals completed an interviewer-administered survey on demographic characteristics, HIV risk behaviors and history of VCT.
In multivariate analysis, females, married individuals, less educated with one sexual partner in the past 6 months were more likely to have had unprotected intercourse in the previous 6 months. Rates of lifetime HIV testing ranged from 5.4% among males in Zimbabwe to 52.6% among females in Soweto.
Significant risk of HIV acquisition in Project Accept communities exists despite two decades of prevention efforts. Low levels of recent HIV testing suggest that increasing awareness of HIV status through accessible VCT services may reduce HIV transmission.
PMCID: PMC2643066  PMID: 18845954
19.  The relationship between social network factors, HIV, and Hepatitis C among injection drug users in Chennai, India 
Drug and alcohol dependence  2011;117(1):50-54.
The purpose of this study was to examine whether social network factors predict HIV and Hepatitis C (HCV) serostatus after controlling for individual-level factors at baseline among a cohort of male injection drug users in Chennai, India.
The sample, which was recruited through street outreach, consists of 1,078 males who reported having injected drugs in the last 6 months
The participants reported 3,936 social support and risk network members. HIV and HCV positive serostatus were negatively associated with network member providing emotional support, and positively associated with network member providing material support. In addition, HCV positivity was associated with network member being an active drug user known for more than 10 years and network member being male kin networks, even after adjusting for individual demographic factors and risk behaviors.
These findings suggest that social network factors are significantly linked to HIV and HCV status among IDUs in Southern India and highlight the mixed effects of social capital on health. Future HIV/HCV prevention efforts should incorporate IDU peers to alter drug network injection risk norms. For drug users who have minimal network support, support groups and other informal and formal support mechanisms may help coping with HIV/HCV and cessation of drug use.
PMCID: PMC3112240  PMID: 21315523
Social networks; HIV; Hepatitis C; India; social capital; injection drug users
20.  Condom nonuse among female sex workers in Chennai, India 
Efforts are required to promote condom use within trusting commercial sex relationships and to reduce unprotected sex resulting from economic coercion and violence.
PMCID: PMC3133810  PMID: 21669420
Condom; Female sex workers; HIV/AIDS; India; Trust; Violence
21.  Expanding the Space: Inclusion of Most-at-Risk Populations in HIV Prevention, Treatment, and Care Services 
The provision of appropriate HIV prevention, treatment, and care services for most-at-risk populations (MARP) will challenge many health care systems. For people who sell sex (SW) or inject drugs (IDU) and for men who have sex with men (MSM), stigma, discrimination, and criminalization can limit access to care, inhibit service uptake, and reduce the disclosure of risks. Several models for provision of HIV services to MARP may address these issues. We discuss integrated models, stand-alone services, and hybrid models, which may be appropriate for some MARP in some settings. Both public health and human rights frameworks concur that those at greatest risk should have expanded access to services.
PMCID: PMC3164959  PMID: 21857306
most-at-risk populations (MARP); HIV; health systems; stigma; discrimination; models of care
22.  Assessing HIV/AIDS Stigma and Discrimination in Developing Countries 
AIDS and behavior  2007;12(5):772-780.
Stigma and discrimination concerning HIV/AIDS has been shown to be a barrier to HIV prevention, voluntary counseling and testing, and care in many international settings. Most published stigma scales are not comprehensive, and have been primarily tested in developed countries. We sought to draw on existing literature to develop a scale with strong psychometric properties that could easily be used in developing countries. From 82 compiled questions, we tested a 50-item scale which yielded 3 dimensions with 22 items in pilot testing in rural northern Thailand (n=200) and urban and peri-urban Zimbabwe (n=221). The 3 factors (Shame, blame and social isolation; discrimination; equity) had high internal consistency reliability and good divergent validity in both research settings. Systematic and significant differences in stigmatizing attitudes were found across countries, with little age or gender differences noted. This short, comprehensive and standardized measure can be easily incorporated into questionnaires in international research settings.
PMCID: PMC2745205  PMID: 18080830
HIV/AIDS-related stigma; discrimination; scale development
23.  Predictors of incident and recurrent participation in the sale or delivery of drugs for profit among young methamphetamine users in Chiang Mai Province Thailand, 2005-2006 
Despite Thailand’s war on drugs, methamphetamine (“yaba” in Thai) use and the drug economy both thrive. This analysis identifies predictors of incident and recurrent involvement in the sale or delivery of drugs for profit among young Thai yaba users.
Between April 2005 and June 2006, 983 yaba users, ages 18-25, were enrolled in a randomized behavioral intervention in Chiang Mai Province (415 index and 568 of their drug network members). Questionnaires administered at baseline, 3-, 6-, 9-, and 12-month follow-up visits assessed socio-demographic factors, current and prior drug use, social network characteristics, sexual risk behaviors and drug use norms. Exposures were lagged by three months (prior visit). Outcomes included incident and recurrent drug economy involvement. Generalized linear mixed models were fit using GLIMMIX (SAS v9.1).
Incident drug economy involvement was predicted by yaba use frequency (Adjusted Odds Ratio [AOR]:1.05; 95% Confidence Interval [CI]: 1.01, 1.10), recent incarceration (AOR: 2.37; 95%CI: 1.07, 5.25) and the proportion of yaba-using networks who quit recently (AOR: .34; 95%CI: .15, .78). Recurrent drug economy involvement was predicted by age (AOR: 0.81; 95% CI: .68, .96), frequency of yaba use (AOR: 1.06; 95%CI: 1.02, 1.09), drug economy involvement at the previous visit (AOR: 2.61; CI: 1.59, 4.28), incarceration in the prior three months (AOR: 2.29; 95%CI: 1.07, 4.86), and the proportion of yaba-users in his/her network who quit recently (AOR: .38; 95%CI: .20, .71).
Individual drug use, drug use in social networks and recent incarceration were predictors of incident and recurrent involvement in the drug economy. These results suggest that interrupting drug use and/or minimizing the influence of drug-using networks may help prevent further involvement in the drug economy. The emergence of recent incarceration as a predictor for both models highlights the need for more appropriate drug rehabilitation programs and demonstrates that continued criminalization of drug users may fuel Thailand’s yaba epidemic.
PMCID: PMC3137701  PMID: 21689916
drug economy involvement; incarceration of drug users; Thailand; war on drugs; adolescents; methamphetamine use; drug network; social network
24.  Increases in Human Papillomavirus Detection During Early HIV Infection Among Women in Zimbabwe 
The Journal of Infectious Diseases  2011;203(8):1182-1191.
Background. Individuals who acquire human immunodeficiency virus (HIV) may experience an immediate disruption of genital tract immunity, altering the ability to mount a local and effective immune response. This study examined the impact of early HIV infection on new detection of human papillomavirus (HPV).
Methods. One hundred fifty-five Zimbabwean women with observation periods before and after HIV acquisition and 486 HIV-uninfected women were selected from a cohort study evaluating hormonal contraceptive use and risk of HIV acquisition. Study visits occurred at 3-month intervals. Cervical swab samples available from up to 6 months before, at, and up to 6 months after the visit when HIV was first detected were typed for 37 HPV genotypes or subtypes.
Results. We observed ∼5-fold higher odds of multiple (≥2) new HPV detections only after HIV acquisition, relative to HIV-negative women after adjusting for sexual behavior and concurrent genital tract infections. We also observed ∼2.5-fold higher odds of single new HPV detections at visits before and after HIV acquisition, relative to HIV-uninfected women in multivariable models.
Conclusions. These findings suggest that HIV infection has an immediate impact on genital tract immunity, as evidenced by the high risk of multiple new HPV detections immediately after HIV acquisition.
PMCID: PMC3068021  PMID: 21451006
25.  Trajectories of Injection Drug Use Over 20 Years (1988–2008) in Baltimore, Maryland 
American Journal of Epidemiology  2011;173(7):829-836.
The objective of this study was to identify longitudinal patterns of injection drug use over 20 years in the AIDS Linked to the Intravenous Experience (ALIVE) Study, a community-based cohort of injection drug users (IDUs) in Baltimore, Maryland, with a focus on injection cessation. Starting in 1988, persons over 18 years of age with a history of injection drug use were recruited into the study. Participants provided information on their injection drug use semiannually through 2008. The analysis was restricted to 1,716 IDUs with at least 8 study visits. Finite mixture models were used to identify trajectories and predictors of injection patterns over time. The mean age of participants was 35 years; 75% were male, and 95% were African-American. Five distinct patterns were identified: 2 usage patterns (32% engaged in persistent injection and 16% had frequent relapse) and 3 cessation patterns (early cessation (19%), delayed cessation (16%), and late cessation (18%)). A history of drug treatment, no recent use of multiple substances, and less frequent injection distinguished the early cessation group from the other groups. This study demonstrated multiple trajectories of drug injection behaviors, with a substantial proportion of IDUs stopping injection over extended time frames. For maximum effectiveness, public health programs for IDUs should be long-term, comprehensive, and targeted toward individual patterns of use.
PMCID: PMC3070496  PMID: 21320867
behavior; HIV; longitudinal studies; substance abuse; intravenous

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