HIV and other STIs in male sex workers: Findings from a sexual health promotion intervention in Vietnam.

Male sex workers (MSWs) in Vietnam are at high risk for acquisition and transmission of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs), yet are extremely disengaged from the healthcare system. This contributes to large numbers of untreated or late-treated infections and increased secondary transmission. We enrolled 995 MSWs in Hanoi and Ho Chi Minh City (HCMC) in a Sexual Health Promotion intervention that included face-to-face delivery of seven content modules, a clinical examination and testing for HIV, syphilis, gonorrhea and Chlamydia. Onsite treatment was provided for STIs, and those who tested positive for HIV were referred to local treatment centers. While 64.6% of participants had never been to a health service and fewer than half (41.2%) had ever been tested for HIV, 67.1% returned for test results. This testing identified 109 (11.0%) participants who were HIV-positive and 312 (31.4%) who tested positive for at least one other STI. Substantive differences were seen in MSWs from different cities, with those from Hanoi more likely to have ever visited a health service (57.8% vs. 24.9%) and to have taken a prior HIV test (54.1% vs. 37.9%) than those in HCMC. Sexual health promotion is a promising approach to engaging MSWs in health services.

Sexual Initiation and Complex Recent Polydrug Use Patterns Among Male Sex Workers in Vietnam: A Preliminary Epidemiological Trajectory.

Little is known about the age of onset of sexual and drug risk and their association with complex patterns of recent drug use among male sex workers (MSW) in a developing country, such as Vietnam. The aim of this study was to determine whether latent class analysis (LCA) would aid in the detection of current individual and polydrug use combinations to predict how different trajectories of sexual and drug initiation contribute to different patterns of current illicit drug use. Data were collected from a cross-sectional survey administered to young MSWs between 2010 and 2011 in Vietnam (N = 710). LCA clustered participants into recent drug use groups, incorporating both the specific types and overall count of different drugs used. Men reported drug use within a 1 month period from an 11-item drug use list. LCA identified three distinct drug use classes: (1) alcohol use, (2) alcohol and tobacco use, and (3) high polydrug use. The current drug use classes are associated with sex worker status, housing stability, income level, educational attainment, marital status, sexual identity, and sexual preferences. High levels of drug use are strongly associated with being a recent sex worker, not having recent stable housing, higher than median income, more than a high school education, less likely to be currently in school and more likely to have non-homosexual preferences and heterosexual partners. An event history analysis approach (time-event displays) examined the timing of the age of onset of drug and sexual risks. Early ages of drug and sexual initiation are seen for all three classes. High current drug users show earlier onset of these risks, which are significantly delayed for moderate and low current drug users. LCA incorporating an overall count of different drugs detected three distinct current drug use classes. The data illustrates that the complexity of drug factors that must be accounted for, both in advancing our epidemiological understanding of the complexity of drug use and the use of drug and sexual risk initiation data to predict current drug use subtypes among high-risk populations.

Prevalence and Correlates of Penile HPV Infection in a Clinic-Based Sample of Hispanic Males.

OBJECTIVE: The aim of this manuscript is to describe the prevalence, genotypic distribution of penile HPV infection and the behavioral risk factors associated with penile HPV infection (any HPV type, high-oncogenic-risk [HR] types, low-oncogenic-risk [LR] types, and of multiple HPV types) in a group of sexually active males who went to an STI clinic in San Juan, Puerto Rico. METHODS: After providing informed consent, the participants, underwent a detailed behavioral interview and a clinical examination. Frequency distributions and descriptive statistics were used to characterize the study samples. Prevalence estimates and 95% confidence intervals (CI) were calculated for any type of HPV, HR types, LR types, or multiple types. Logistic regression analyses was performed to determine factors associated with each of the HPV types. RESULTS: Two hundred and six participants were enrolled in this study. The mean age of the participants was 37.8±13.1 years. Close to 80% of the sample were infected with at least one HPV type; 73.5% were infected with one or more LR-HPV types; 32.4%, with one or more HR-HPV types; and 46.0%, with multiple HPV types. The most prevalent HR types were HPV-35, -31, and -16; the most prevalent LR types were HPV 6/11, and -84. After adjusting for age, having a high number of lifetime female sexual partners was highly associated with having multiple types of HPV infection (estimated OR=2.86; 95% CI=1.41, 5.80). CONCLUSION: HPV infection is common among sexually active males frequenting this STI clinic. HPV types not covered by the current quadrivalent HPV vaccine were identified. Multiple HPV types in the penis are significantly related to the lifetime number of female sexual partners. The high prevalence of HPV at this particular STI clinic evidences that males need to be targeted in primary care settings if the available vaccine is to be effectively promoted. In addition, opportunities for secondary prevention of HPV in STI settings are recommended, because of the burden of anal and penile cancer documented in the island.

Sexual practices, partner concurrency and high rates of sexually transmissible infections among male sex workers in three cities in Vietnam.

UNLABELLED: Background This paper examines sexual practices, partner concurrency and sexually transmissible infections (STI)/HIV infection among male sex workers (MSWs) in Vietnam. METHODS: Six hundred and fifty-four MSWs, aged 16-35 years, were recruited in Hanoi, Nha Trang and Ho Chi Minh City between 2009 and 2011. Survey measures included demographic characteristics, drug use, types of sexual partners and sexual practices. Subjects were screened for STIs, including HIV. RESULTS: MSWs in Ho Chi Minh City (33%) were more likely than those from the other two sites to be current users of one or more types of illegal drugs (P<0.001). MSWs with both male and female elective partners (compared with other partnership types) were more likely to have anal sex with male client partners (P<0.001), elective male partners (P=0.045) and elective female partners (P=0.025). At last sex with a male client partner, only 30% used a condom during anal intercourse. At last sex with an elective female partner, only 31% used a condom during vaginal sex and only 3% during anal sex. Although rates of HIV are low (4%), other STIs are high, including chlamydia (17%), gonorrhoea (29%) and human papillomavirus (33%). Most (57.3%) have never been tested for HIV and only 17% have ever disclosed to a healthcare provider that they have sex with men. CONCLUSIONS: Complex patterns of sexual concurrency, coupled with high rates of STIs, signal the urgent need for health services interventions among MSWs, both to improve individual health outcomes and to reduce secondary STI/HIV transmission among sexual partner networks.

Substance use among male sex workers in Vietnam: prevalence, onset, and interactions with sexual risk.

BACKGROUND: HIV research in Vietnam has focused primarily on its large heroin injector population. Data on men who have sex with men [MSM], particularly the large and growing population of men who exchange sex for money or other material rewards, male sex workers [MSWs], is very limited. METHODS: Data derive from a cross-sectional study of MSW, age 16-35, recruited using community sampling methods in three cities in 2010-2011, including Hanoi, Ho Chi Minh City [HCMC], and Nha Trang City (n=710). Assessments included demographic characteristics, substance use, sexual risk, and use of health services. A series of "event" questions were used to assess the influence of alcohol and drugs on sexual risk. RESULTS: Both tobacco and alcohol are initiated at a young age and most participants currently use both substances overall across all three cities. While alcohol and tobacco use precede the initiation of sex work, stimulant and opiate use are initiated following the initiation of sex work. There was substantial overlap between substance use and sexual risk, and this overlap was strongest in sexual events involving male and female elective partners rather than sex work clients. CONCLUSION: Although rates of HIV infection in this group are low, this may be an artifact of the young age of the sample. High rates of drug use, including alcohol, tobacco and illicit drugs, coupled with high rates of ulcerative STIs such as HPV, suggest the potential for rapid amplification of STI/HIV risk among MSW and their complex sex partnering networks.

Epidemiology of anal HPV infection in high-risk men attending a sexually transmitted infection clinic in Puerto Rico.

PURPOSE: Recent studies in Puerto Rico have reported an increasing incidence of anal cancer in Puerto Rican men. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among men attending an STI clinic in Puerto Rico. METHODS: We conducted a cross-sectional study among 205 men 18 years and older. A comprehensive survey was administered that included a demographic and a behavioral assessment. Separate logistic regression models were performed to determine factors associated with any, high-risk (HR), and multiple anal HPV infection. RESULTS: The mean age of the study sample was 38.0±13.5 years. The most common HR types were 58, 51 and 31. Overall, HR anal HPV infection was found in 53.5% of the participants. Multiple HPV types in the anal canal were found in 47.6% of the sample. A third (29.8%) of participants reported being men who had sex with men (MSM). MSM had a significantly higher prevalence of any, HR and multiple HPV infection (p-value<0.05). Separate multivariate logistic regression analyses showed that being MSM was associated with any (OR = 4.5; [95%CI: 1.9-10.7]), HR (OR = 3.4; [95%CI: 1.1-10.3) and multiple anal HPV infection (OR = 3.6; [95%CI: 1.5-9.1). HIV was marginally associated with multiple anal HPV infection in multivariate analysis (OR = 3.3; 95%CI = 1.0-11.0). CONCLUSIONS: Anal HPV is common among sexually active men attending this STI clinic, with higher likelihood of anal HPV infection among MSM.

Awareness and knowledge of human papillomavirus (HPV) infection among high-risk men of Hispanic origin attending a sexually transmitted infection (STI) clinic.

BACKGROUND: Genital human papillomavirus (HPV) is one of the most commonly diagnosed sexually transmitted infection (STIs) in men and women. Knowledge about HPV infection among men is limited. This study aims to determine correlates of adequate knowledge of HPV infection among men who attend an STI clinic in Puerto Rico. METHODS: A cross-sectional study of 206 men was conducted at an STI clinic in San Juan, PR. Adequate knowledge was defined as a score of at least 70% of correct responses among those men who reported having ever heard of HPV. Variables that achieved statistical significance in the bivariate analysis (p<0.05) were included in the multivariate logistic regression model. RESULTS: Although 52.5% of men reported having heard of HPV infection before the survey, only 29.3% of this sub-group had an adequate knowledge of HPV. Most men did not know that HPV is a risk factor for anal (38.7%), penile (50.0%) and oral (72.6%) cancer. Factors associated with adequate knowledge of HPV in age-adjusted models were being men who have sex with men (MSM) (OR=2.6;95%CI=1.1-6.1), self-report of genital warts (OR=3.2;95%CI=1.3-7.9) and herpes (OR=7.4;95% CI=2.2-25.1). MSM was marginally associated with adequate knowledge (OR=2.3;95% CI=0.9-5.9) and self-report of herpes remained significantly associated (OR=5.0;95%CI=1.3-18.4) in multivariate logistic regression analysis. CONCLUSIONS: Awareness and knowledge of HPV was very low in this group of men. Interventions to increase knowledge and awareness in this group are necessary to promote preventive practices for HPV-related cancers in high-risk groups.

Accelerated transition to injection among male heroin initiates in Hanoi, Vietnam: implications for early harm reduction interventions.

This paper examines changes in the interval between first heroin smoking and onset of injection in a large, out-treatment sample of male heroin users in Hanoi, Vietnam (n = 1,115). Mean age at initiation of heroin use (smoking) was 18.4 and mean age of onset of heroin injection was 20.9 years. Full multivariate analysis indicates that the interval between first heroin use (smoking) and first heroin injection has been significantly attenuated among more recent heroin initiates (P = 0.0043), suggesting that heroin users in Vietnam may be at increased risk for exposure to HIV relatively soon after onset of heroin use, highlighting the need for behavioral interventions that target heroin smokers. Critical intervention goals include delaying the onset of injection and improved education about safer drug sharing and drug injection practices.

Nonmedical use of promethazine hydrochloride among heroin injectors in Vietnam: unrecognized risks and unintended consequences.

BACKGROUND: Surveillance studies have noted intravenous injection of promethazine hydrochloride (PHC) among populations that use heroin in south and southeast Asia. However, little is known about onset and initiation of PHC use and its relationship to habitual heroin use. METHODS: As part of a longitudinal study of heroin initiation, a sample of 179 new heroin users, aged 15-27 years, were interviewed between October 2005 and December 2006 in Hanoi, Vietnam. Cox proportional hazard regression analysis was used to characterize age at promethazine initiation and its association with relevant covariates. RESULTS: 76% reported lifetime use of PHC. Mean age of PHC initiation was 21.3 years, on average 6 months following onset of heroin injection. In multivariate analysis, lifetime use of diazepam [HR = 1.69 (1.17, 2.44); p-value = .01] and injecting heroin for more than 1.58 years [HR = 1.46 (1.04, 2.06); p-value = .03] were associated with PHC initiation. CONCLUSION: Intravenous injection of PHC is a relatively common practice among young injection heroin users in Hanoi, Vietnam who use it on a situational basis to substitute for heroin (when heroin is not available or when heroin is too costly) or to augment the effects of an inadequate heroin dosing (delaying onset of heroin withdraw). Existing drug prevention strategies in Vietnam are focused primarily on heroin and most new heroin users initiate PHC use without prior knowledge of its high risk for serious vein damage. Future research is needed on the PHC use among heroin users, including long-term medical consequences of PHC exposure.

Prevalence and incidence of HCV infection among Vietnam heroin users with recent onset of injection.

HCV infection continues to spread at an alarming rate among IDU populations. The available evidence suggests that HCV is acquired relatively quickly following onset of injection. However, there are few prospective studies of HCV acquisition, particularly among IDU populations in resource-poor settings. A sample of young male heroin injectors with recent onset of injection (<4 years) was recruited in Hanoi, Vietnam for a prospective assessment of the early course of injection (n = 179). Both behavioral and biological assessments (including detailed retrospective assessment of injection initiation) were conducted at baseline and repeated at 6-month intervals for a period of 16 months. Variables associated with HCV infection (p value < 0.05) in bivariate analyses were considered for inclusion in logistic regression models to identify risk factors independently associated with HCV infection. HCV incidence was calculated by using the incidence density approach and was expressed in terms of person-years of observation. The baseline of prevalence of HCV was 46%. HCV significantly increased in relation to time since first injection, from 30% in subjects with /=30 months injection risk (p value = 0.0005). In multivariate logistic regression analysis, increasing age, incarceration in a drug detention facility (OR = 2.54; 95%CI 1.05, 6.15), and time since first injection remained significantly associated with HCV infection. Use of injection as primary mode of administration (OR = 2.56; 95%CI 0.98, 6.69) achieved marginal significance. After 16 months of follow-up, the incidence rate of HCV was 23.35 per 100 person-years and the mean time between first injection and first positive HCV test was 1.2 years. HCV is acquired much more rapidly among new injector populations than previously recognized, demonstrating the need for early behavioral intervention among new heroin-user populations. Particularly critical are interventions that target new heroin user populations, including interventions that improve understanding of viral transmission dynamics, that promote alternative strategies for drug sharing, and that delay initiation of injection.

Alternatives to the randomized controlled trial.

Public health researchers are addressing new research questions (e.g., effects of environmental tobacco smoke, Hurricane Katrina) for which the randomized controlled trial (RCT) may not be a feasible option. Drawing on the potential outcomes framework (Rubin Causal Model) and Campbellian perspectives, we consider alternative research designs that permit relatively strong causal inferences. In randomized encouragement designs, participants are randomly invited to participate in one of the treatment conditions, but are allowed to decide whether to receive treatment. In quantitative assignment designs, treatment is assigned on the basis of a quantitative measure (e.g., need, merit, risk). In observational studies, treatment assignment is unknown and presumed to be nonrandom. Major threats to the validity of each design and statistical strategies for mitigating those threats are presented.

Novel heroin injection practices: implications for transmission of HIV and other bloodborne pathogens.

BACKGROUND: This paper describes injection risk in an out-of-treatment population of young heroin users in Hanoi, Vietnam, including use of a soft-tissue portal known as a "cay ma" (injection sac). METHODS: Data from a large cross-sectional survey (N=1270) are used to describe the prevalence of this practice and its association with disease. Additionally, data from an ethnographic substudy on injectors serve to elaborate injectors' rationales for this injection practice. RESULTS: This practice was common in this sample, appearing soon after initiation of habitual injection. Injectors report that this allows rapid and reliable access to a vein; strategic advantages in a dense urban environment where rapid injection, typically in public settings, is necessary to avoid discovery or arrest. Additionally, this practice is believed to mitigate risk for vein damage from co-morbid promethazine hydrochloride injection. CONCLUSIONS: This practice may draw lymphocytes to injection sites, thereby increasing risk for transmission of bloodborne pathogens. Structural and behavioral interventions are needed for young heroin users in Vietnam.

Prevalence and Patterns of Prescription Drug Misuse among Young Ketamine Injectors.

In recent years, epidemiological monitoring data has indicated sharp increases in prescription drug misuse. Despite these increases, little is known about the context or patterns associated with prescription drug misuse, particularly among youth or young injection drug users (IDUs). A three-city study of 213 young IDUs found prescription drug misuse to be pervasive, specifically the use of opioids and benzodiazepines. Particular practices not commonly associated with prescription drugs were reported, such as sniffing, smoking, and injection. Associated health risks included initiation into injection drug use, polydrug use, drug overdose, and drug dependency. A greater awareness of the potential health risks associated with prescription drug misuse should be incorporated into services that target IDUs, including street outreach, syringe exchanges, and drug treatment.

The relationship between club drug use and other drug use: a survey of New York City middle school students.

In order to explore the relationship between use of club drugs (crystal methamphetamine, ecstasy, GHB, ketamine), and use of other drugs, survey data collected from 23,780 middle school students in New York City during 2002-2003 was examined. Results of HGLM analyses (a generalization of HLM to accommodate nonlinear outcomes), controlling for the effect of school, indicate that Black students are less likely than White students to use club drugs depending on the timeframe of use. The use of alcohol and/or marijuana predict club drug use regardless of the timeframe of use, and lifetime cigarette use predicts lifetime club drug use. Recommendations for future research and prevention efforts are discussed.