Time-location Sampling Research Articles

Blood donation history and eligibility assessment in a community-based sample of men who have sex with men.

In 2016, the US Food and Drug Administration changed the regulation from a permanent deferral from donation for men who have sex with men (MSM) to a 1-year deferral since last sexual contact. It is unknown what proportions of MSM try to donate and if they would be willing to answer individual risk-based questions to assess their current eligibility. The National HIV Behavioral Surveillance surveys periodically measure human immunodeficiency virus (HIV) prevalence and risk behaviors among MSM using a venue-based, time-location sampling method. In the 2014 cycle, that is, before the policy change, investigators in San Francisco and New Orleans added questions about blood donation. Questions inquired into three domains: donation history, policy awareness, and knowledge about HIV testing of donations. There were 404 and 557 respondents in San Francisco and New Orleans, respectively. Nearly one in three MSM in San Francisco (27.4%) and New Orleans (31.4%) tried to donate after their first MSM contact. A majority (63.1% in San Francisco, 58.8% in New Orleans) somewhat or strongly agreed that they would be willing to be asked detailed questions for donation eligibility assessment. The proportion of MSM who reported trying to donate was similar in the two cities. However, a substantial proportion did not agree to be asked more detailed risk behavior questions to assess eligibility. In these two geographic locations, prominent regional differences were not evident.

The role of venues in structuring HIV, sexually transmitted infections, and risk networks among men who have sex with men

BackgroundVenues form part of the sampling frame for time-location sampling, an approach often used for HIV surveillance. While sampling location is often regarded as a nuisance factor, venues may play a central role in structuring risk networks. We investigated individual reports of risk behaviors and infections among men who have sex with men (MSM) attending different venues to examine structuring of HIV risk behaviors. However, teasing apart ‘risky people’ from ‘risky places’ is difficult, as individuals cannot be randomized to attend different venues. However, we can emulate this statistically using marginal structural models, which inversely weight individuals according to their estimated probability of attending the venue.MethodsWe conducted a cross-sectional survey of 609 MSM patrons of 14 bars in San Diego, California, recruited using the Priorities for Local AIDS Control Efforts (PLACE) methodology, which consists of a multi-level identification and assessment of venues for HIV risk through population surveys.Results and discussionVenues differed by many factors, including participants’ reported age, ethnicity, number of lifetime male partners, past sexually transmitted infection (STI), and HIV status. In multivariable marginal structural models, venues demonstrated structuring of HIV+ status, past STI, and methamphetamine use, independently of individual-level characteristics.ConclusionsStudies using time-location sampling should consider venue as an important covariate, and the use of marginal structural models may help to identify risky venues. This may assist in widespread, economically feasible and sustainable targeted surveillance and prevention. A more mechanistic understanding of how ‘risky venues’ emerge and structure risk is needed.

Depression, Loneliness, and Sexual Risk-Taking Among HIV-Negative/Unknown Men Who Have Sex with Men in China.

Research conducted among men who have sex with men (MSM) in high-income countries has demonstrated that negative mental health is one of the significant drivers of HIV infection, and few studies have examined the status of mental health among MSM in China. We sought to describe depression and loneliness and identify their correlates among Chinese MSM. A cross-sectional study was conducted among HIV-negative or unknown status MSM in 2014. Time-location sampling and online convenience sampling methods were employed. Depression was measured via a short version of CES-D (CES-D 10). Loneliness was measured from a single item in CES-D 10. Multivariable logistic regressions were conducted to identify independent correlates of depression and loneliness. A total of 507 individuals participated in the study. Of them, 26.8 and 35.5% reported moderate-to-severe symptoms of depression and feeling lonely, respectively. Depressed participants were more likely to have a sense of hopelessness for the future (AOR 3.20, 95% CI 1.90, 5.20) and report higher levels of internalized homophobia (AOR 2.32, 95% CI 1.47, 3.67). Participants who reported feeling lonely were more likely to have had condomless receptive anal intercourse in the past 6months (AOR 1.67, 95% CI 1.08, 2.58) and feel hopeless for the future (AOR 2.40, 95% CI 1.60, 3.70). MSM in China have significant rates of depression and loneliness. HIV prevention efforts should address the mental health needs of Chinese MSM such as providing safe environments for social support and role models.

Previous HIV testing behavior and related factors in men who have sex with men in gay bathroom in Hangzhou, Zhejiang province

Objective: To understand the related factors on previous HIV testing behavior among MSM who visit gay bathroom in Hangzhou, Zhejiang province. Methods: Through time-location sampling (TLS) survey, men who had oral sex or anal sex with men in past 6 months were interviewed in the gay bathroom in Hangzhou from October 2015 to January 2016. Software SPSS 22.0 was used to analyze the HIV testing acceptance, sexual behaviors and condom usage of MSM during past 6 months, and χ(2) test and logistic regression model were used for univariate and multivariate analyses. Results: Our study planned to recruit 480 gay bathroom MSM, due to the unwilling or other factors, 465 MSM were surveyed. A total of 47.3% (220/465) gay bathroom MSM received HIV testing during past 6 months. Multivariate analysis indicated that being married (OR=0.35, 95%CI: 0.18-0.69), peer education (OR=4.31, 95%CI: 1.32-14.09), homosexual behavior during past 6 months (OR=1.85, 95%CI: 1.08-3.14), extramarital heterosexual behavior during past 6 months (OR=4.12, 95%CI: 2.45-6.91) might be positive factors related with HIV testing acceptation in MSM. Conclusion: Being married, homosexual behavior during past 6 months, extramarital heterosexual behavior, partner education might be the positive factors related with acceptance of HIV testing among gay bathroom MSM. Therefore, peer education needs to be strengthened. HIV testing after high risk sexual behavior needs to be promoted in MSM.

HIV Prevalence and Risk Behaviors in Male to Female (MTF) Transgender Persons in Tijuana, Mexico.

Compared to HIV research on men who have sex with men, less is known about the risks and vulnerabilities for HIV among Male to Female (MTF) transgender persons, particularly in different geographic regions like Mexico. In Tijuana, Mexico, a border city experiencing a dynamic HIV epidemic, no precedent data exists on the MTF transgender population. Our aims were to estimate HIV prevalence and examine the behaviors and characteristics of the population. We conducted a cross-sectional study of 100 MTF transgender persons recruited through time location sampling in 2012. Participants underwent interviewer-administered (paper and pen) surveys and rapid tests for HIV. Descriptive univariate analyses were conducted on various factors, including sociodemographics, substance use, accessing social services (requested vs. received), stigma, and sex behaviors. A total of 22% tested positive for HIV, a prevalence higher than other key populations at risk for HIV in Tijuana.

Awareness and compliance to anti-smoking law in South Bengaluru, India.

INTRODUCTIONTobacco smoke affects the health of non-smokers by exposure to second-hand smoke (SHS). The Indian Cigarettes and Other Tobacco Products (COTPA) Act 2003 Section 4 aims to reduce exposure to SHS. Awareness and compliance to COTPA are key to achieving its intended outcome. We assessed: a) awareness among persons responsible for compliance (PRC) and authorized officers (AO), and b) compliance of public places to COTPA in South Bengaluru, India.METHODSA cross-sectional assessment of public places in South Bengaluru was conducted using time-location sampling. The Johns Hopkins Bloomberg School of Public Health’s observational and interview checklist was used to assess compliance of public places to COTPA and awareness of COTPA among PRC/AO, respectively.RESULTSAmong 359 public places, one-third of the public places showed complete (1.9%) or partial compliance (28.1%). The majority (93%) of the PRCs and all AOs were aware of COTPA. However, they lacked information on the different provisions of the Act. Violations like persons smoking (3.9%), visible ashtrays (6%) and cigarette butts (13%) were noted more among eateries compared to other public places. Among those public places supposed to have designated smoking-areas, only 19% complied.CONCLUSIONSThis is the first representative survey of awareness and compliance of COTPA in Bengaluru City. Low compliance, coupled with the lack of appropriate awareness among PRCs and AOs about COTPA, demands a comprehensive strategy to enhance awareness. Comprehensive efforts towards making all stakeholders understand the health impacts of smoking, and strict enforcement, might facilitate effective implementation of COTPA.

Efficacy of Human Immunodeficiency Virus/Sexually Transmitted Infection Trial on Condom Use Among Heterosexual Men Patronizing Entertainment Establishments Who Engaged in Casual or Paid Sex in Singapore.

We assessed the efficacy of a multi-component sexual health promotion program on condom use and human immunodeficiency virus (HIV)/sexually transmitted infection (STI) testing among heterosexual men (HSM) patronizing entertainment establishments who engaged in casual or paid sex in Singapore. This was a quasi-experimental trial with a comparison group using cross-sectional surveys at baseline and 6 months postintervention. A locality patronized by local HSM was assigned the intervention, a comparable and distant area served as the comparison site. Using time location sampling, cross-sectional samples of these men were assessed on sexual behaviors using an anonymous questionnaire at baseline (n = 604) and 6 months postintervention (n = 360) in both groups. The coprimary outcomes were condom use at last vaginal and oral sex with casual partner respectively. Mixed effects Poisson regression model accounting for clustering by establishment was used to compute the adjusted prevalence ratio (aPR) of the outcomes postintervention. At postintervention, the intervention group was more likely than the comparison group to report condom use at last vaginal (aPR, 1.41; 95% confidence interval [CI], 1.05-1.89) and oral (aPR, 1.70; 95% CI. 1.11-2.61) sex, respectively, with casual partner. Similar findings were found for consistent condom use in the last 6 months for vaginal (aPR, 1.67; 95% CI, 1.13-2.48) and oral (aPR, 1.97; 95% CI, 1.16-3.32) sex, respectively, with casual partner. The HIV/STI testing was not significantly higher in the intervention than the comparison group (aPR, 1.43; 95% CI, 0.98-2.09). This trial was effective in promoting condom use with casual partners but not HIV/STI testing among HSM in Singapore.

A typology of female sex work in the Metropolitan Region of Santiago, Chile

In Chile, sex work takes place covertly in a variety of venues and locations. Formative research using time-location sampling methods is important in order to understand the nature of this diversity. This study used qualitative methods to develop a typology of female sex work in the Metropolitan Region of Santiago, Chile, using semi-structured interviews, focus groups and ethnographic fieldwork during visits to sex work venues. The study identified seven types of venue, which reflect the context and regulatory framework of the country and the structural vulnerabilities that affect female sex workers in Chile. These venues and locations include: cafés con piernas (coffee with legs); nightclubs, topless bars and cabarets; brothels; hotels; street and highway soliciting; massage parlours; and private residences. Formative research methods were helpful in identifying and characterising the venues and locations in which sex work occurred. Barriers to accessing and mapping specific locations were also identified. Recommendations for addressing these barriers include working with non-governmental organisations to map venues and initiate contact with the populations of interest. A comprehensive typology of sex work in the Metropolitan Region of Santiago, Chile, is an essential element for future time-location sampling and bio-behavioural research in the context of second-generation surveillance for HIV and sexually transmitted infections in Chile.

Ensuring Inclusion of Adolescent Key Populations at Higher Risk of HIV Exposure: Recommendations for Conducting Biological Behavioral Surveillance Surveys.

Ending acquired immune deficiency syndrome (AIDS) depends on greater efforts to reduce new human immunodeficiency virus (HIV) infections and prevent AIDS-related deaths among key populations at highest HIV risk, including males who have sex with males, sex workers, and people who inject drugs. Although adolescent key populations (AKP) are disproportionately affected by HIV, they have been largely ignored in HIV biological behavioral surveillance survey (BBSS) activities to date. This paper reviews current ethical and sampling challenges and provides suggestions to ensure AKP are included in surveillance activities, with the aim being to enhance evidence-informed, strategic, and targeted funding allocations and programs toward ending AIDS among AKP. HIV BBSS, conducted every few years worldwide among adult key populations, provide information on HIV and other infections’ prevalence, HIV testing, risk behaviors, program coverage, and when at least three of these surveys are conducted, trend data with which to evaluate progress. We provide suggestions and recommendations on how to make the case to ethical review boards to involve AKP in surveillance while assuring that AKP are properly protected. We also describe two widely used probability sampling methods, time location sampling and respondent driven sampling, and offer considerations of feature modifications when sampling AKP. Effectively responding to AKP’s HIV and sexual risks requires the inclusion of AKP in HIV BBSS activities. The implementation of strategies to overcome barriers to including AKP in HIV BBSS will result in more effective and targeted prevention and intervention programs directly suited to the needs of AKP.

HIV Treatment and Re-infection Beliefs Predict Sexual Risk Behavior of Men Who Have Sex With Men.

We examined whether beliefs about antiretroviral (ART) efficacy and reinfection prospectively predicted subsequent condomless anal intercourse (CAI). Men who have sex with men in San Francisco (N = 773) were recruited for a longitudinal study using time-location sampling. HIV-negative men were more likely to have sero-discordant receptive CAI and HIV-positive men were more likely to have sero-discordant insertive CAI if they previously reported these behaviors at baseline and reported less concern about HIV transmission due to ART. HIV-positive men were more likely to report sero-concordant CAI at follow-up if they reported this behavior at baseline. Previous sexual behavior was consistently the strongest predictor of future sexual behavior. Previous sexual behavior and optimistic beliefs about ART for treatment and prevention predicted subsequent sexual behavior with sero-discordant partners. Since individual-level and population-level benefits of ART depend on persons maintaining adequate drug concentrations, prevention messages should continue emphasizing treatment adherence and practicing a combination of risk-reduction strategies.

Theory versus practice, bacteriological efficiency versus personal habits: A bacteriological and user acceptability evaluation of filtering tools for people who inject drugs.

People who inject drugs (PWID) are exposed to associated viral, bacterial and fungal risks. These risks can be reduced by filtration. Large disparities in the quality of filtration exist between the various available filters. This paper compares both performance and user acceptability of three filters for drug injection (cotton filters, Sterifilt® and wheel filters) by combining epidemiological and bacteriological analyses. A cross-sectional epidemiological study (ANRS-Coquelicot) using time-location sampling combined with the generalised weight sampling method was conducted among 985 PWID in France. Two filtration-based bacteriological studies of 0.20- and 0.45-μm wheel filters, Sterifilt filters and cotton filters were also conducted. The bacteriological study highlighted the value of using wheel filters with a porosity of less than 0.5 μm, as they limit the risk of bacterial and fungal infection. The results of this study clearly highlight a distinction between the efficiency of Sterifilt and wheel filters, the latter being more effective. Our epidemiological study highlighted that the use of cotton filters is widespread and routine, but is the subject of much criticism among PWID. Sterifilt is not widely used, and its adoption is slow. Finally, the wheel filter remains a largely untested tool. Low product retention and ease of use are the two most important factors for filters for PWID. Bacterial and fungal risk filtration is less important. It is essential to educate PWID about the benefits of wheel filters. [Jauffret-Roustide M, Chollet A, Santos A, Benoit T, Péchiné S, Duplessy C, Bara J-L, Lévi Y, Karolak S, Néfau T. Theory versus practice, bacteriological efficiency versus personal habits: A bacteriological and user acceptability evaluation of filtering tools for people who inject drugs. Drug Alcohol Rev 2018;37:106-115].

First HIV prevalence estimates of a representative sample of adult sub-Saharan African migrants in a European city. Results of a community-based, cross-sectional study in Antwerp, Belgium.

IntroductionWhile sub-Saharan African migrants are the second largest group affected by HIV in Europe, sound HIV prevalence estimates based on representative samples of these heterogeneous communities are lacking. Such data are needed to inform prevention and public health policy.MethodsThis community-based, cross-sectional study combined oral fluid HIV testing with an electronic behavioral survey. Adopting a two-stage time location sampling HIV prevalence estimates for a representative sample of adult sub-Saharan African migrants in Antwerp, Belgium were obtained. Sample proportions and estimated adjusted population proportions were calculated for all variables. Univariable and multivariable logistic regression analysis explored factors independently associated with HIV infection.ResultsBetween December 2013 and October 2014, 744 sub-Saharan African migrants were included (37% women). A substantial proportion was socially, legally and economically vulnerable: 21% were probably of undocumented status, 63% had financial problems in the last year and 9% lacked stable housing. Sexual networks were mostly African and crossed national borders, i.e. sexual encounters during travels within Europa and Africa. Concurrency is common, 34% of those in a stable relationship had a partner on the side in the last year. HIV prevalence was 5.9%(95%CI:3.4%-10.1%) among women and 4.2% (95%CI:1.6%-10.6%) among men. Although high lifetime HIV testing was reported at community level (73%), 65.2% (CI95%:32.4%-88.0%) of sub-Saharan African migrants were possibly undiagnosed. Being 45 years or older, unprotected sex when travelling within Europe in the last year, high intentions to use condoms, being unaware of their last sexual partners’ HIV status, recent HIV testing and not having encountered partner violence in the last year were independently associated with HIV infection in multivariable logical regression. In univariable analysis, HIV infection was additionally associated to unemployment.ConclusionsThis is the first HIV prevalence study among adult sub-Saharan African migrants resettling in a European city based on a representative sample. HIV prevalence was high and could potentially increase further due to the high number of people with an undiagnosed HIV infection, social vulnerability, high levels of concurrency and mainly African sexual networks. Given this population’s mobility, an aligned European combination prevention approach addressing these determinants is urgently needed.

Access to mental health services among internally displaced persons in Ukraine: Results from a nationwide survey

BackgroundThere are an estimated 1.4 million internally displaced persons (IDPs) in Ukraine as a result of the armed conflict in Ukraine.Objectives(i) Measure the burden of key mental disorders (PTSD, depression and anxiety); (ii) examine rates of utilization of health and psychosocial support services; (iii) examine the patterns of utilisation of services.MethodsThe study used a cross-sectional survey design and was conducted throughout Ukraine between March and May 2016 with 2203 IDPs aged 18 years and over. Time-location sampling was chosen as a probabilistic sampling method. Outcome measures were the PCL-5 for PTSD, the PHQ-9 for depression and the GAD-7 for anxiety. Descriptive and multivariate regression analyses were used.ResultsOf the 2203 respondents, 703 reported experiencing a mental health or emotional problem over the previous 12 months and were also screened positive with PTSD, depression or anxiety. Of these 703, 180 had sought care (with sources of care to be given in the presentation). Therefore, 523 respondents did not seek care, equating to an overall treatment gap of 74%, (74% for PTSD, 71% for depression and 70% for anxiety). Key reasons for not utilising treatment included preferring to use their own medications (n = 176); unaffordability of health services (n = 118) or medications (n = 140); poor understanding by health care providers (n = 123); poor quality of services (n = 78) and stigma/embarrassment (n = 41).ConclusionsThe findings support the need for a scaled-up, comprehensive and trauma informed response to provision of the mental health care of IDPs in Ukraine.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Índice de vulnerabilidad al VIH en población habitante de calle

Objetivo. Se reconoce que las vulnerabilidades sociales tienden a ocurrir con el VIH, pero pocos estudios han tratado de medir la vulnerabilidad al VIH y no se logra identificar en la literatura la unificación frente al concepto y la manera de operativizarlo. El objetivo de esta investigación fue determinar un índice de vulnerabilidad, y su relación con la infección por VIH en población habitante de calle de la ciudad de Medellín<br /><br />Material y método. Se realizó un estudio descriptivo transversal con 338 habitantes de calle de Medellín utilizando el muestreo de tiempo y lugar. En la construcción del índice se realizó un análisis factorial de tipo exploratorio y un análisis factorial confirmatorio. <br /><br />Resultados. Se identificaron cuatro factores que explicaron el 50,49% de la varianza. Se encontró que la población con alta vulnerabilidad al VIH tenía cinco veces el riesgo de tener VIH, esta asociación fue ajustada por variables sociodemográficas de edad, sexo, estado civil y nivel de escolaridad.<br /><br />Conclusiones. Se propone un índice de vulnerabilidad al VIH, el cual se definió como la reducción de la capacidad de anticiparse (conocimientos y creencias erróneas), resistirse (prácticas sexuales y consumo de drogas) y recuperarse (apoyo social y rechazo). Lo cual limita la capacidad para acceder a servicios de prevención, atención, y apoyo al VIH.<br /><br />

High HIV Prevalence and Risk Among Male Clients of Female Sex Workers in Hanoi and Ho Chi Minh City, Vietnam.

In Vietnam's concentrated HIV epidemic, female sex workers (FSWs) are at increased risk for acquiring and transmitting HIV, largely through their male clients. A high proportion of males in Vietnam report being clients of FSWs. Studying HIV-related risk factors and prevalence among male clients is important, particularly given the potential for male clients to be a 'bridge' of HIV transmission to the more general population or to sex workers. Time-location sampling was used to identify FSW in Hanoi and Ho Chi Minh City, Vietnam's largest cities, in 2013-2014. Recruited FSWs were asked to refer one male client to the study. Demographic and risk behavior data were collected from FSWs and male clients by administered questionnaires. Biologic specimens collected from male clients were tested for HIV and opiates. Sampling weights, calculated based on the FSWs probability of being selected for enrolment, were applied to prevalence estimates for both FSWs and male clients. Logistic regression models were developed to obtain odds ratios for HIV infection among male clients. A total of 804 male clients were enrolled. Overall, HIV prevalence among male clients was 10.2%; HIV prevalence was 20.7% (95% confidence interval (CI) 15.0-27.9%) among those reporting a history of illegal drug use and 32.4% (95% CI 20.2-47.7%) among those with opioids detected in urine. HIV prevalence among male clients did not differ across 'bridging' categories defined by condom use with FSWs and regular partners over the previous 6months. HIV among male clients was associated with a reported history of illegal drug use (OR 3.76; 95% CI 1.87-7.56), current opioid use (OR 2.55; 95% CI 1.02-6.36), and being referred by an FSW who self-reported as HIV-positive (OR 5.37; 95% CI 1.46-19.75). Self-reported HIV prevalence among enrolled FSWs was 2.8%. Based on HIV test results of male clients and self-reported status from FSWs, an estimated 12.1% of male client-FSW pairs were sero-discordant. These results indicate high HIV prevalence among male clients of FSWs, particularly among those with a history of drug use. Programs to expand HIV testing, drug-use harm reduction, and HIV treatment for HIV-infected male clients of FSWs should be considered as key interventions for controlling the HIV epidemic in Vietnam.

A Multi-US City Assessment of Awareness and Uptake of Pre-exposure Prophylaxis (PrEP) for HIV Prevention Among Black Men and Transgender Women Who Have Sex with Men.

The HIV epidemic among Black men and transgender women who have sex with men (BMTW) demands an urgent public health response. HIV point prevalence among this population ranges from 25 to 43%-a rate far exceeding any other group. Pre-exposure prophylaxis (PrEP) for HIV prevention is a very promising prevention tool; however, its full potential to slow the epidemic has yet to be realized. For the current study, random time-location sampling at Black Gay Pride Events was used to collect data from N = 1274 BMTW, from five US cities, reporting HIV-negative/unknown status. In-field HIV testing was also provided to participants. Participants were assessed on awareness and use of PrEP, health care factors, HIV testing history, psychosocial variables, and sex behaviors. About one third of participants were aware of PrEP (39%), and a small percentage of participants were users of PrEP (4.6%). In multivariable analyses, being in a relationship, testing for HIV in the past 6months, and others being aware of one's sexuality were positively associated with PrEP awareness. Higher levels of internalized homophobia and greater numbers of female sex partners were positively associated with PrEP use, while education and condom use were negatively associated. Based on study findings, messaging and uptake of PrEP needs greater expansion and requires novel approaches for scale-up. Improving linkage to HIV testing services is likely critical for engaging BMTW with PrEP. The potential for PrEP to slow the HIV epidemic is high; however, we must strengthen efforts to ensure universal availability and uptake.

High HIV prevalence and associated risk factors among female sex workers in Rwanda

Human immunodeficiency virus (HIV) prevalence is often high among female sex workers (FSWs) in sub-Saharan Africa. Understanding the dynamics of HIV infection in this key population is critical to developing appropriate prevention strategies. We aimed to describe the prevalence and associated risk factors among a sample of FSWs in Rwanda from a survey conducted in 2010. A cross-sectional biological and behavioral survey was conducted among FSWs in Rwanda. Time-location sampling was used for participant recruitment from 4 to 18 February 2010. HIV testing was done using HIV rapid diagnostic tests (RDT) as per Rwandan national guidelines at the time of the survey. Elisa tests were simultaneously done on all samples tested HIV-positive on RDT. Proportions were used for sample description; multivariable logistic regression model was performed to analyze factors associated with HIV infection. Of 1338 women included in the study, 1112 consented to HIV testing, and the overall HIV prevalence was 51.0%. Sixty percent had been engaged in sex work for less than five years and 80% were street based. In multivariable logistic regression, HIV prevalence was higher in FSWs 25 years or older (adjusted odds ratio [aOR] = 1.83, 95% [confidence interval (CI): 1.42-2.37]), FSWs with consistent condom use in the last 30 days (aOR = 1.39, [95% CI: 1.05-1.82]), and FSWs experiencing at least one STI symptom in the last 12 months (aOR = 1.74 [95% CI: 1.34-2.26]). There was an inverse relationship between HIV prevalence and comprehensive HIV knowledge (aOR = 0.65, [95% CI: 0.48-0.88]). HIV prevalence was high among a sample of FSWs in Rwanda, and successful prevention strategies should focus on HIV education, treatment of sexually transmitted infections, and proper and consistent condom use using an outreach approach.

Similarities and differences in crack cocaine use patterns in Santa Catarina, Brazil: Capital vs. Midwest.

Crack cocaine has been a major public health problem in Brazil due to the individual and social harms and risks deriving from its use. This article aims to assess the characteristics of drug scenes in the capital and Midwest of Santa Catarina state. The project used the Time-Location Sampling. Between January and June 2011, 41 crack cocaine scenes were mapped in capital of Santa Catarina, whereas 33 were mapped in the Midwest of that state. Such scenes were randomly selected to be observed, as well as their days and shifts (time periods/day) for in-depth observation. Overall, 98 scenes/shifts were observed in the capital and 62 in the Midwest. First-hand reports were logged as field notes into notebooks. Analyses of the empirical material were based on Bardin's content analysis, and findings were compared and contrasted with Brazilian and international literature. Most crack cocaine users were adult males. In the capital, a substantial fraction of the users lived in the streets, but in both settings most interviewees have used multiple substances. In the Midwest, most scenes occurred at night, whereas in the capital scenes occurred in all shifts. Risk practices associated with the use of crack cocaine were: association of multiple drugs, prostitution, pipe sharing and sexual favors in exchange for the substance.

HIV Research with Men who Have Sex with Men (MSM): Advantages and Challenges of Different Methods for Most Appropriately Targeting a Key Population.

The difficulty in accessing hard-to-reach populations as men who have sex with men presents a dilemma for HIV surveillance as their omission from surveillance systems leaves significant gaps in our understanding of HIV/AIDS epidemics. Several methods for recruiting difficult-to-access populations and collecting data on trends of HIV prevalence and behavioural factors for surveillance and research purposes have emerged. This paper aims to critically review different sampling approaches, from chain-referral and venue-based to respondent-driven, time-location and internet sampling methods, focusing on its main advantages and challenges for conducting HIV research among key populations, such as men who have sex with men. The benefits of using these approaches to recruit participants must be weighed against privacy concerns inherent in any social situation or health condition. Nevertheless, the methods discussed in this paper represent some of the best efforts to effectively reach most-at-risk subgroups of men who have sex with men, contributing to obtain unbiased trends of HIV prevalence and HIV-related risk behaviours among this population group.

The Where and How for Reaching Transgender Women and Men Who Have Sex with Men with HIV Prevention Services in Guatemala.

This study aims to describe the transgender women and men who have sex with men (MSM) missed through venue-based sampling and illustrate how data on venues can be used to prioritize service delivery. Respondent-driven sampling (RDS) and time-location sampling (TLS) were used concurrently in 2010 for behavioral surveillance among MSM and transgender women in Guatemala City. RDS recruits who did not frequent venues (n=106) were compared to TLS recruits (n=609). TLS participants recruited at different types of venues were compared. RDS recruits who did not frequent venues were less educated, less likely to identify as gay, more likely to have concurrent partners and female sexual partners. Participants recruited at NGOs, saunas, hotels, streets and parks had more partners, were more likely to receive money for sex or have concurrent partners. Prevention programs for MSM and transgender women should characterize social venues and people that frequent them and improve service coverage through venues and social networks.