Hidden populations: discovering the differences between the known and the unknown drug using populations in the Republic of Georgia.

BACKGROUND: The HIV epidemic in Georgia is increasing. Data shows that compared to previous years, Georgia has increasingly more HIV-infected individuals than previous assessments. Select client groups remain hard to reach by harm reduction programs. The need for innovative strategies to involve these individuals is imperative. METHODS: The following study examines demographics and risk factors of participants, previously known and not known to harm reduction services, for HIV and other infectious disease in towns across Georgia in 2015 and compares risk among different groups, while also assessing the rationale for implementing Peer-Driven Interventions in Georgian Harm Reduction activities. Important differences in demographics and risk profile are thought to exist between those exposed, and those unexposed, to harm reduction activity. RESULTS: Important and striking differences between previously known and unknown participants, including demographic background and risk profile and behaviours exist in the drug using community. These differences can potentially explain some of the rise of HIV prevalence in Georgia. CONCLUSION: Significant differences exist between known and unknown drug users in Georgia, the differences between which are crucial for planning future and holistic harm reduction activities in Georgia, regionally and globally. The research advocates for smarter harm reduction activity, adds to the global evidence for the utility of Peer-Driven Intervention, and encourages sustained global effort for reduction of blood-borne disease burden globally.

Closing the Gap? The HIV Continuum in Care for African-American Men Who Have Sex with Men, San Francisco, 2004-2014.

We examined trends in the HIV continuum in care in the National HIV Behavioral Surveillance surveys for MSM in San Francisco from 2004 to 2014. In 2004, HIV-positive African-American MSM were less likely to be diagnosed (42.9 vs. 87.5 %, p = 0.003), linked to care (42.9 vs. 85.7 %, p = 0.007), or to have ever used antiretroviral treatment (ART) (28.6 vs. 69.6 %, p = 0.032) compared to white MSM. By 2014, these gaps had narrowed but not closed, including diagnosis (85.7 vs. 100 %, Fisher's exact p = 0.106), linkage to care (85.7 vs. 96.8 %, Fisher's exact p = 0.290), and ART use (85.7 vs. 94.9 %, Fisher's exact p = 0.369).

Investigating HIV Infection and HIV Incidence Among Chinese Men Who Have Sex with Men with Recent Sexual Debut, Chongqing, China, 2011.

HIV among men who have sex with men (MSM) with recent male-male sexual debut, such as within the past 5 years, may be a proxy for recent HIV infection. Using this definition, we explored factors associated with HIV infection in this group to understand the evolving HIV epidemic among MSM in Chongqing. We conducted a cross-sectional respondent-driven sampling survey among Chongqing MSM in 2011. Computer-assisted, self-administered questionnaires were used and blood specimens were collected for HIV and syphilis testing. Three hundred and ninety-one unique MSM were recruited of which 65.7 % (257) had their sexual debut with another man in the past 5 years. HIV prevalence among men with recent sexual debut was 18.7 % suggesting a possible HIV incidence of 3.7 %. Multivariable analysis among men with recent sexual debut suggests that lower education, having more than one male partner, and currently being infected with syphilis are associated with HIV among men with recent sexual debut. HIV prevalence is high among MSM with recent sexual debut in Chongqing, which may be a proxy a high incidence rate. HIV prevention efforts should focus on STD reduction among those MSM with lower educational attainment.

A Comparison of Men Who Have Sex with Men, People Who Inject Drugs and High-Risk Heterosexuals' Risk for HIV Infection, San Francisco.

HIV in the United States is concentrated in populations such as men who have sex with men (MSM), people who inject drugs (PWID), women of color and people living in poverty. These populations are labeled high-risk for HIV infection because of the higher levels of HIV or HIV risk taking behaviors seen in these groups compared to other sub-populations. It is also possible that a group may engage in behaviors that are "high-risk" for HIV infection but never become infected since HIV is not present or not present to a great extent in their social or sexual networks. We analyzed samples of MSM, PWID and high-risk heterosexuals (HRH) collected through the National HIV Behavioral Surveillance (NHBS) system in San Francisco to examine HIV risk taking and HIV burden to determine if the label "high-risk" is appropriately applied. NHBS samples MSM using time location sampling and PWID and HRH using Respondent Driven Sampling. We sampled 508 MSM in 2011, 570 PWID in 2012 and 267 HRH in 2013. There were, as expected, differences in demographic characteristics across the three groups. HRH had a greater number of high-risk behaviors compared to MSM and PWID but had the lowest HIV prevalence. Focusing on risk behavior alone to label populations without considering the background HIV prevalence in communities, the types of risks engaged in and actual HIV infections may obscure which populations truly merit the label "high-risk" for HIV infection.

Migration and HIV Risk Among Men Who Have Sex With Men, San Francisco, 2011.

In San Francisco, MSM account for nearly 90% of HIV infections. Studies have postulated increased risk for HIV faced by MSM who migrate, particularly to urban environments, yet empirical data are lacking. In this study we analyzed data from the National HIV Behavioral Surveillance System collected in 2011 to ascertain whether nativity (U.S. versus foreign born) was associated with HIV prevalence, risk behavior, and service use. Among 510 MSM enrolled, HIV prevalence was 23.0%. Multivariable analyses demonstrate that while nativity was not associated with increased risk for HIV infection, those who had lived in San Francisco for more than five years had higher HIV prevalence compared to those who had lived for less than a year even after adjusting for age, race, income, education, and location of birth.

Efforts to Find Heterosexual HIV in San Francisco, 2007-2013.

Nationally heterosexuals are an HIV prevention priority. In addition to case based HIV surveillance, behavioral surveillance surveys are conducted among heterosexuals living in high AIDS morbidity neighborhoods. We report on risk behaviors and HIV prevalence among "high-risk" heterosexuals in San Francisco. National HIV Behavioral Surveillance System is coordinated by the CDC and implemented in 21 health jurisdictions. The studies were conducted in 2006, 2010 and 2013 in San Francisco. Respondent driven sampling was used to sample participants. Eligible persons were 18-50 years old and had sex with at least one opposite gender partner in the past year. We obtained samples of 371, 421, 165 heterosexuals in 2007, 2010 and 2013, respectively. Some demographics varied across the 3 years. Residential neighborhoods changed, homelessness and healthcare coverage increased. Binge drinking, cocaine and heroin use increased while methamphetamine use declined. There were no changes in numbers of partners, unprotected vaginal intercourse or unprotected anal intercourse. Commercial sex work increased. Even with "fine tuning" of eligibility criteria to attempt to find heterosexual HIV cases, we estimate that HIV prevalence was 0.3, 0.2 and 2.4 % in 2007, 2010 and 2013 respectively. The increase was not statistically significant. For the present, effective prevention among persons in the populations most severely affected by HIV remains the priority, for their own benefit and to prevent transmission to other vulnerable populations to which they may be connected.

K-mer natural vector and its application to the phylogenetic analysis of genetic sequences.

Based on the well-known k-mer model, we propose a k-mer natural vector model for representing a genetic sequence based on the numbers and distributions of k-mers in the sequence. We show that there exists a one-to-one correspondence between a genetic sequence and its associated k-mer natural vector. The k-mer natural vector method can be easily and quickly used to perform phylogenetic analysis of genetic sequences without requiring evolutionary models or human intervention. Whole or partial genomes can be handled more effective with our proposed method. It is applied to the phylogenetic analysis of genetic sequences, and the obtaining results fully demonstrate that the k-mer natural vector method is a very powerful tool for analysing and annotating genetic sequences and determining evolutionary relationships both in terms of accuracy and efficiency.

HIV prevention services and testing utilization behaviors among men who have sex with men at elevated risk for HIV in Chongqing, China.

OBJECTIVE: To investigate barriers and correlates of the use of HIV prevention services and HIV testing behaviors among men who have sex with men in Chongqing. METHODS: Three consecutive cross-sectional surveys provided demographic, sexual behavior, HIV/syphilis infection, HIV prevention service, and testing behavior data. RESULTS: Of 1239 participants, 15.4% were infected with HIV, incidence was 12.3 per 100 persons/year (95% CI: 9.2-15.3), 38% of the participants reported ever having unprotected insertive anal sex, 40% ever received free condom/lubricants in the past year, and 27.7% ever obtained free sexually transmitted infection examination/treatment in the past year. Multivariable logistic regression revealed that lower levels of HIV/AIDS related stigmatizing/discriminatory attitudes, full-time jobs, and sex debut with men at a younger age were independently associated with use of free condom/lubricants. Large social networks, higher incomes, and sexual debut with men at a younger age were associated with use of any HIV prevention and HIV testing services. Lower levels of stigmatizing/discriminatory attitudes were also associated with HIV testing. Fearing needles and being unaware of the venues for testing were top barriers for testing service utilization. CONCLUSION: It is imperative to address HIV/AIDS related stigmatizing/discriminatory attitudes and other barriers while delivering intervention and testing services.

The role of individual and neighborhood factors: HIV acquisition risk among high-risk populations in San Francisco.

We examined socioeconomic status and social and sexual network factors and their relationship to HIV acquisition risk among HIV-negative Black MSM (BMSM), White MSM (WMSM) and transfemales (male to female transgenders). Geographic analysis examined residential patterns and neighborhood patterns of HIV prevalence in San Francisco. Factors associated with engaging in more episodes of potentially HIV serodiscordant unprotected receptive anal intercourse were analyzed. Transfemales and BMSM were more likely to live in areas of higher HIV prevalence and lower income compared to WMSM. BMSM and transfemales had lower socioeconomic scores (SES) scores compared to WMSM. BMSM were more likely to report serodiscordant partnerships and higher numbers of potentially serodiscordant unprotected sex acts. Decreasing individual SES did not predict serodiscordant partnerships in any group. Increasing neighborhood HIV prevalence predicted an increase in the number of potentially serodiscordant unprotected sex acts among transfemales and BMSM but only significantly so for transfemales. Prevention interventions must consider neighborhood HIV prevalence, and HIV prevalence in social/sexual networks, in addition to considering individual level behavior change or poverty reduction.

Internalized homonegativity/homophobia is associated with HIV-risk behaviours among Ugandan gay and bisexual men.

We investigated the relationship of internalized homonegativity/homophobia (IH) to sexual risk behaviours among 216 Ugandan gay and bisexual men, using the 7-item IH scale previously developed on this population. IH was significantly associated with unprotected anal intercourse, and more so with unprotected receptive anal intercourse. Higher IH was also associated with more sex while intoxicated. There was a strong association between anal intercourse of any type and IH, suggesting a complex relationship between anal sex and identification with, or internalization of, homonegativity/homophobia. Specifically, it may be the anal component of sex rather than the sex with another man that is seen as labeling one as homosexual or stigmatizing. Those men who stated that they engaged in sex with other men for love, rather than for the physical feeling or for money, had higher IH scores. These data suggest that there may be an interactive relationship between IH and sexual behaviour, with greater internalization being associated with more stereotypically gay activities, which in turn may lead to more self-identification as gay and thus greater susceptibility to internalization.

Mutual HIV disclosure among HIV-negative men who have sex with men in Beijing, China, 2010.

HIV is rising rapidly among Chinese men who have sex with men (MSM). Discussion of HIV status between sexual partners is potentially a key prevention behavior. It is unclear if HIV-negative Chinese MSM talk about HIV and disclose their HIV status with sexual partners. Understanding the correlates of disclosure among this population could provide insight into developing disclosure-based interventions. We conducted a respondent driven sampling based study of 500 MSM in Beijing. A total of 332 men had a previous HIV-negative test result and thus considered themselves to be HIV-negative and were included in our analysis of disclosure. Equal numbers of these men reported talking about HIV and disclosing their HIV status to at least one sexual partner. MSM who disclosed were more likely to be living with a main partner. No other demographic characteristics were associated with disclosure in bivariate analysis. We also used data on up to three sexual partners per participant to examine disclosure on the partnership level. Main partnerships, meeting partners at bars/clubs, sometimes using alcohol before sex in a partnership, and usually having sex at home compared to other venues were associated with disclosure. Using generalized estimating equation analysis to characterize individuals from their partnership data, we found only having at least one main partnership and knowing people who were infected with HIV to be associated with a participant being a discloser. Interventions that wish to harness discussion of HIV and HIV status among Chinese MSM will need to focus on moving these discussions towards having them with casual partners.

HIV/AIDS-related stigmatizing and discriminatory attitudes and recent HIV testing among men who have sex with men in Beijing.

This study assessed the correlates of recent HIV testing and HIV/AIDS-related stigmatizing and discriminatory attitudes among men who have sex with men (MSM) in Beijing, China. A cross-sectional study probed demographics, sexual and drug use behaviors, HIV testing, and prevention services. Of 500 participants, 39.3% recently received a test for HIV. Recent testing was independently associated with expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes, more male sex partners, no female sexual partners and knowing HIV status of their last male partner. Expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes was independently associated with recent testing, younger age, and knowing HIV status of their last male partner. This study revealed that HIV/AIDS-related stigmatizing and discriminatory attitudes were common and inversely associated with recent HIV testing. Low levels of testing highlighted the urgent needs to reduce HIV/AIDS-related stigma and discrimination and expand HIV testing among MSM in Beijing.

Behavioral and serologic survey of men who have sex with men in Beijing, China: implication for HIV intervention.

We assessed HIV prevalence and associated behaviors and risk factors among men who have sex with men (MSM) in Beijing, China. Five hundred MSM were recruited for a biological and behavioral survey using respondent-driven sampling (RDS) in 2009. Serologic specimens were tested for markers of HIV and syphilis infection. A computer-assisted personal interview (CAPI) administered questionnaire gathered information including demographic characteristics, sexual behaviors, HIV testing, and social norms concerning condom use. The adjusted HIV prevalence was 8.0%, syphilis 22.0%. HIV testing and disclosure was low; only 39.3% had HIV tested in the past 12 months, 49.7% knew their own HIV status and 22.8% knew their last male partner's HIV status. HIV infection was associated with syphilis, ever having sex with a woman, not knowing the HIV status of the most recent male partner, and never buying condoms in the past 12 months. Stronger endorsement of positive social norms around condom use strongly and predicted lower prevalence of HIV infection. Compared to surveys of similar design in the recent past, HIV continues to spread rapidly among Beijing's MSM. Our results identify points of intervention that, if addressed in time, may still alter the course of the epidemic including the promotion of HIV testing and partner disclosure, syphilis control and particularly changing social norms around condom use.

Untested and undiagnosed: barriers to HIV testing among men who have sex with men, Beijing, China.

OBJECTIVES: Undiagnosed HIV presents great potential for the spread of infection. The authors identify the prevalence and correlates of never testing and being unaware of HIV infection in Beijing men who have sex with men (MSM). METHODS: Cross-sectional biological and behavioural survey using respondent-driven sampling; 500 MSM were included. RESULTS: HIV prevalence was 7.2% with 86.1% unaware of their infection; 33.2% had never tested. Never testing was associated with lower educational (adjusted odds ratio (AOR) 1.6, 95% CI (CI) 1.1 to 2.5), living in Beijing for ≤3 years (AOR 1.5, 95% CI 1.0 to 2.3), unprotected anal intercourse with most recent male partner (AOR 1.6, 95% CI 1.0 to 2.4), being unaware of the most recent male partner's HIV status (AOR 3.6, 95% CI 2.1 to 6.1) and holding stigmatised attitudes towards persons with HIV (AOR 1.1 per scale point, 95% CI 1.0 to 1.1). Predictors of having undiagnosed HIV infection were being married (AOR 2.4, 95% CI 1.0 to 5.4), living in Beijing for ≤3 years (AOR 3.6, 95% CI 1.5 to 8.4), being unaware of the most recent male partner's HIV status (AOR 6.8, 95% CI 0.9 to 51.6) and holding negative attitudes towards safe sex (AOR 1.1 per scale point, 95% CI 1.0 to 1.1). CONCLUSIONS: Recent attention has focused on HIV prevention interventions that depend upon knowing one's serostatus, including viral load suppression, prevention with positives, pre-exposure prophylaxis and seroadaptation. Until the low level of testing and resulting high level of undiagnosed HIV infection are addressed, these tools are not likely to be effective for MSM in China.

Willingness to participate in HIV vaccine clinical trials among Chinese men who have sex with men.

HIV vaccine trials require volunteers. Little is known about willingness to participate (WTP) in HIV vaccine trials among Chinese MSM. A survey of 550 MSM was conducted from March to June 2008, in Beijing, China. Data were collected on demographics, behaviors, perceptions about HIV/AIDS and HIV vaccines, and concerns about participation in HIV vaccine clinical trials. Of study participants, 35.8% were definitely willing to participate, 35.1% were probably willing, 16.4% were probably not willing, and 12.7% were definitely not willing. Analyses suggest that perceived family support, perceived protection against HIV infection and fear that participation would result in social distancing were associated with WTP. MSM in China may be good candidates for HIV vaccine trials. Further studies are needed to evaluate actual enrollment.

HIV prevalence and related risk factors among male sex workers in Shenzhen, China: results from a time-location sampling survey.

BACKGROUND: HIV transmission among men who have sex with men has recently become a major concern in China. Little is known, however, about HIV transmission among male sex workers (MSW). This study aimed to investigate HIV infection prevalence and risk factors among MSW in Shenzhen, China. MATERIALS AND METHODS: Following formative research, a cross-sectional study was conducted using time-location sampling among MSW in Shenzhen, from April to July 2008. Behavioural and serological data on HIV and syphilis were collected. The risk factors for HIV infection were analysed using a logistic regression model. RESULTS: In total, 394 MSW were recruited for the survey. The prevalence of HIV and syphilis among these workers was 5.3% and 14.3%, respectively. Only a quarter of the MSW self-identified as homosexual. More than 70% had sex with both men and women. HIV-related knowledge levels were high regardless of HIV serostatus. Consistent condom use was low (37.1%) and varied by type of sexual partner. Factors including more non-commercial male partners, working in small home-based family clubs, being drunk before sexual intercourse, having a history of HIV tests, syphilis infection and a short period of residence in Shenzhen were associated with an increased risk of HIV infection. CONCLUSIONS: High-risk sexual practices were common among MSW regardless of their high level of HIV awareness. The working venues were associated with HIV infection and a recent test for HIV was a potential predictor of HIV infection. The time-location sampling method was found to be an appropriate way of recruiting MSW for this study, especially those without fixed working places.

Concurrent sexual partnerships and racial disparities in HIV infection among men who have sex with men.

OBJECTIVES: To measure the level of sexual partner concurrency and assess its potential role in explaining disparities in HIV prevalence by race/ethnicity among men who have sex with men (MSM). METHODS: A cross-sectional, community-based survey of MSM in San Francisco was conducted in 2008 using time-location sampling. Four different measures of sexual partner concurrency were assessed and compared across race/ethnicity groups: overlap in time with the most recent sexual partners, knowledge of the most recent sexual partner having other partners, any overlap with up to the last five partners and complete overlap with up to the last five partners. RESULTS: A total of 521 MSM was recruited; 10% self-described their race/ethnicity as black, 62% as white, 25% as Latino and 9% as Asian (not mutually exclusive). Black MSM had fewer sexual partners overall, yet had three times the odds that all their partnerships were concurrent compared with non-black MSM (39% vs 17%, respectively, p = 0.034). None of the other measures of concurrency showed racial/ethnic differences. MSM whose partnerships were completely concurrent had a higher number of sexual episodes and unprotected sexual episodes per partnership compared with those whose partners were not completely concurrent. CONCLUSIONS: Findings support the hypothesis that the sexual networks of black MSM rather than individual behaviours account for their higher prevalence of HIV compared with non-black MSM. There remains the need specifically to validate different concurrency measures in larger samples and directly assess them as risk factors for acquiring HIV infection.

Prevalence of seroadaptive behaviours of men who have sex with men, San Francisco, 2004.

OBJECTIVES: To define and measure the prevalence of HIV seroadaptive behaviours among men who have sex with men (MSM). METHODS: A community-based, cross-sectional sample of 1211 HIV negative and 251 HIV positive MSM was recruited in San Francisco in 2004 by time-location sampling. Seroadaptive behaviours were defined by enumerating and characterising all episodes of anal intercourse by partner type, partner HIV serostatus, sexual position and condom use for up to five partners in the preceding 6 months. RESULTS: Among HIV negative MSM, 37.6% engaged in some form of apparent seroadaptive behaviour, predominantly pure serosorting (24.7%), followed by seropositioning (5.9%), condom serosorting (3.9%) and negotiated safety (3.1%). Among HIV positive men, 43.4% engaged in some form of seroadaptation, including pure serosorting (19.5%), seropositioning (14.3%) and condom serosorting (9.6%). Consistent condom use was reported by 37.1% of HIV negative and 20.7% of HIV positive MSM. CONCLUSIONS: In aggregate, seroadaptive behaviours appear to be the most common HIV prevention strategy adopted by MSM in San Francisco as of 2004. Surveillance and epidemiological studies need to precisely measure seroadaptive behaviours in order to gauge and track the true level of HIV risk in populations. Rigorous prevention research is needed to assess the efficacy of seroadaptive behaviours on individuals' risk and on the epidemic.

High prevalence of risk behaviour concurrent with links to other high-risk populations: a potentially explosive HIV epidemic among men who have sex with men in Guangzhou, China.

OBJECTIVES: HIV disproportionately affects men who have sex with men (MSM), but HIV prevalence among MSM in Guangzhou has not shown the rapid increasing trend as it has elsewhere in China. The aim of this study is to detect the epidemic and to determine the characteristics of MSM in Guangzhou susceptible to HIV. METHODS: A cross-sectional survey with serological testing for HIV, syphilis, HBV and HCV through long-chain referral sampling strategy to help control the bias generated from non-statistic sampling. RESULTS: The most important features of MSM in Guangzhou are being young and mobile, and of comparable education and income level to that of the general population. The HIV prevalence was 1.3% (95% CI 0.3 to 2.7%) in 2006. Many HIV risk factors were identified: low awareness of HIV risk perception and prevention, high prevalence of diverse, multiple partners and versatile sexual role, more than half of them actively having sex with women, low persistent condom use with both male and female partners, commercial sex and one out of 27 practising needle or syringe sharing during illicit drug use. CONCLUSION: HIV has been introduced into MSM in Guangzhou. Demographic and behavioural risk factors and overlapping risk populations contribute to a potentially rapidly rising epidemic among MSM and the potential for a bridge to female partners in Guangzhou if timely and effective interventions are not implemented.