Respondent-Driven Sampling Analysis Tool Research Articles

HIV and associated factors among female sex workers in Tajikistan: Analysis from a national bio-behavioral survey.

Tajikistan, a country of approximately nine million people, has a relatively small but quickly growing HIV epidemic. No peer-reviewed study has assessed factors associated with HIV, or associated risk factors, among female sex workers (FSWs) in Tajikistan. The purpose of the current study is to elucidate the factors associated with HIV status and risk factors in the Tajikistani context and add to the scant literature on risk factors among FSWs in Tajikistan and Central Asia. We used cross-sectional data from an HIV bio-behavioral survey (BBS) conducted among FSWs in the Republic of Tajikistan (n = 2174) in 2017. Using Respondent Driven Sampling Analysis Tool software, we calculated the prevalence of HIV, diagnosed cases, linkage to antiretroviral therapy (ART), and the prevalence of syphilis for FSWs in Tajikistan. Prevalence data were adjusted for network size and any clustering effects in the network. Further, using univariate and multivariable logistic regression, we determined correlates of HIV-positive status. Results were as follows: Of all FSWs in Tajikistan, 2.6% (95% CI: 1.7-3.8%) are HIV positive, 2.3% (95% CI: 1.4-3.5%) are diagnosed and aware of their status, and 2.0% (95% CI: 1.2-3.1%) are on ART. About 5.7% (95% CI: 4.5-7.4%) of FSWs in Tajikistan have ever had syphilis, and 0.8% (95% CI: 0.4-1.3%) have active syphilis infections. The epidemic of injection drug use was found to be strongly synergistic with HIV infection as having had sex with a person who injects drugs was shown to be strongly associated with HIV-positive status (OR: 5.2; 95% CI: 2.6-10.2) in the multivariable model. While this study estimates that HIV prevalence among Tajikistani FSWs is relatively low, it is likely an underestimated due to selection and social desirability biases. To curb the small, but potentially volatile, HIV epidemic among FSWs, the government should consider targeted testing and linkage-to-care efforts for FSWs who inject drugs or who have people who inject drugs partners. Services should also be prioritized in Gorno-Badakhshan, which has a higher number of FSWs per capita relative to other regions. Additionally, the link between HIV and experiences of stigma, violence, and discrimination against FSWs should motivate advocates to protect Tajikistani FSWs from these experiences.

Fish consumption and awareness of fish advisories among Burmese refugees: A respondent-driven sampling study in Milwaukee, Wisconsin

BackgroundSince 2000, more than 6000 Burmese refugees were resettled in Wisconsin. The Burmese diet is traditionally rich in fish and fish products, and studies show that Burmese refugees continue to rely on local waterbodies for food. Given that Wisconsin has five Areas of Concern (AOC) that are severely affected by pollution, long-term exposure to contaminants in sport-caught fish is a health concern. To better understand fish consumption among Burmese refugees, we conducted a biomonitoring study in Milwaukee. The present study examined Burmese refugees’ fish consumption habits and awareness of fish advisories. MethodsWe used respondent-driven sampling (RDS) methodology to recruit Burmese refugees in Milwaukee. RDS Analysis Tool 7.1 was used to obtain adjusted population estimates for demographic characteristics, fish consumption habits, and awareness of fish advisories. Homophily and equilibrium were investigated to evaluate the effectiveness of RDS in recruitment. ResultsInitiated by five active seeds, we recruited 103 respondents to participate in the study. Respondents had a strong preference to recruit those with the same ethnicity (Homophily-score: 0.614 to 0.699) and a relatively weak preference to recruit those with the same sex (Homophily-score: 0.188 to 0.222) to participate in our study. The majority (72.5%) of respondents were women of childbearing age (WCBA). Most (68.5%) had 8th grade or less education. Regarding sportfish consumption per month in the last year, 30.6% reported eating 1–3 meals and 21.2% reported eating more than 3 meals. When asked about purchased fish consumption per month, 26.3% reported eating 1–3 meals. The overwhelming majority were not aware of safe-eating sportfish guidelines for Wisconsin (88.3%) or Milwaukee waterbodies (96.6%). ConclusionsRDS is an effective methodology to recruit hard-to-reach populations, such as the Burmese surveyed in this study. High percentages of WCBA eating potentially contaminated sportfish meals, low awareness of consumption advisories, and limited economic resources make the Burmese population more likely to be exposed to contaminants. Health education efforts should be focused in this vulnerable population, particularly among Burmese WCBA.

Mis-anaesthetized society: expectancies and recreational use of ketamine in Taiwan

BackgroundThe popularity of ketamine for recreational use has been increasing in Asia, including Taiwan. Still, little known about the pattern of ketamine expectancies and whether such patterns are related to ketamine use. This study aimed to examine whether the positive and negative ketamine expectancies are differentially associated with ketamine-using behavior, and whether such relationship may differ by early-onset use of tobacco or alcohol.MethodsParticipants were recruited using respondent-driven sampling (RDS) among regular tobacco and alcohol users, aged 18 to 50, residing in Taipei from 2007 to 2010. Totally 1115 participants (with an age distribution skewed to the right, median = 26; interquartile range: 22–32) had information on substance use and completed a 12-item ketamine expectancies questionnaire (with 6 positive and 6 negative statements). Using two axes of High and Low expectancies, the four combinations of binary positive and binary negative ketamine expectancies were created. Each participant’s drug-using experience was categorized into illicit drug naïve, exclusive ketamine use, polydrug ketamine use, or other illicit drug use. Using the weights in the network output by RDS Analysis Tool, multivariable logistic regression analysis was then conducted.ResultsThe weighted prevalence was 2.4% for exclusive ketamine use, 9.0% for polydrug ketamine use, and 9.1% for the other illicit drug use. Ketamine users (11.4%) had greater positive expectancies and lower negative expectancies, particularly the combination of High Positive with Low Negative, as compared to the illicit drug-naïve or other illicit drug users. After adjustment for early-onset tobacco (or alcohol) use and sociodemographic characteristics, High Positive, Low Negative, and their combination of High Positive-Low Negative expectancies remained strongly associated with ketamine uses, without evidence of moderation from early-onset use of tobacco or alcohol.ConclusionsPositive and negative ketamine expectancies were associated in opposite directions with ketamine use, independent of early-onset use of tobacco or alcohol. Our results indicate ketamine expectancies as possible targets for future intervention and prevention of ketamine use, with a less confrontational feedback on decreasing an individual’s positive expectancies is essential in preventing young people from the initiation of ketamine use.

Human immunodeficiency virus (HIV) among men who have sex with men: results of the first integrated biological and behavioral survey in Burkina Faso, West Africa

BackgroundMany men who have sex with men (MSM) are at significant risk for HIV infection. The objective of this study was to determine the prevalence and correlates of HIV infection among MSM in Burkina Faso.MethodsA cross-sectional biological and behavioral survey was conducted from January to August 2013 among MSM in Ouagadougou and Bobo-Dioulasso. MSM 18 years old and above were recruited using respondent driven sampling (RDS). A survey was administered to study participants followed by HIV testing. Population prevalence estimates and 95% confidence intervals (CI) adjusted for the RDS design were produced using the RDS Analysis Tool version 6.0.1 (RDS, Inc., Ithaca, NY).ResultsA total of 662 MSM were enrolled in Ouagadougou (n = 333) and Bobo-Dioulasso (n = 329). The majority were unmarried, with an average age of 22.1 ± 4.4 years old in Ouagadougou and 23.1 ± 4.7 years old in Bobo-Dioulasso. RDS-adjusted HIV prevalence was 1.7% (95% CI: 0.9–3.1) in Ouagadougou and 2.7% (95% CI: 1.6–4.6) in Bobo-Dioulasso. HIV prevalence among MSM under 25 years old was 1.3% (95% CI: 0.6–2.8) and 0.9% (95% CI: 0.4–2.5) respectively in Ouagadougou and Bobo-Dioulasso, compared to 5.4% (95% CI: 2.2–12.5) and 6.6% (95% CI: 3.4–12.3) among those 25 years old or older in these cities (p = 0.010 and p < 0.001).ConclusionsResults from this first biological and behavioral survey among MSM in Burkina Faso suggest a need for programs to raise awareness among MSM and promote safer sex, particularly for young MSM to prevent HIV transmission. These programs would need support from donors for innovative actions such as promoting and providing pre-exposure prophylaxis, condoms and water-based lubricants, HIV counseling, testing, early treatment initiation and effective involvement of the MSM communities.

Hepatitis B, C, and D virus and human T-cell leukemia virus types 1 and 2 infections and correlates among men who have sex with men in Ouagadougou, Burkina Faso

BackgroundMen who have sex with men (MSM) are considered to be at significant risk for sexually transmitted infections (STI) and bloodborne viruses including viral hepatitis types B, C, and D (HBV, HCV, and HDV) and human T-cell leukemia virus types 1 and 2 (HTLV 1&2). This study aimed to assess the seroprevalence and correlates of HBV, HCV, HDV, and HTLV 1&2 antibodies among MSM in Ouagadougou, Burkina Faso.MethodsWe conducted a cross-sectional survey to assess the biological and behavourial characteristics among MSM in Ouagadougou from January to April 2013. Serum specimens obtained were tested for the presence of HBV, HCV, HDV and HTLV-1&2 infections. MSM 18 years and older were recruited using respondent driven sampling (RDS). Population estimates and 95% confidence intervals (CI) adjusted for the RDS design were calculated using RDS Analysis Tool (RDSAT) version 6.0.1 (RDS, Inc., Ithaca, NY). Bivariate and multivariate logistic regression analyses were conducted to assess correlates of these infections using Stata 14.ResultsA total of 329 MSM were tested. Prevalence was 20.4% (95% CI: 16.4–25.1) for HBV, 11.0% (95% CI: 8.0–14.8) for HCV, and 0.0% for HDV. Anti-HTLV 1&2 antibodies were found in 4.0% (95% CI: 2.3–6.8) of MSM. Factors independently associated with HBV infection were lack of condom use during the last anal sex act with a main male sexual partner and experience of condom tearing during anal sex. Presence of anti-HTLV 1&2 antibodies was associated with history of genital or anal lesions and injection drug use. None of the variables included in our study were associated with HCV.ConclusionsThis study shows that HBV, HCV and HTLV 1&2 prevalence among MSM in Burkina is high and suggests that comprehensive STI prevention and sexual health education services for this group are needed.

A preliminary needs assessment of American Indians who inject drugs in northeastern Montana

BackgroundInjection drug use has not been well documented in American Indians living in the USA. American Indian and Alaskan Natives (AI/ANs) show higher rates of substance use compared to the general population, and have historically been subject to a number of risk factors that are known to increase the likelihood of substance use. AI/ANs also experience increased risk for infectious diseases that are transmitted via injection drug use and/or sexual activity. Harm reduction approaches have been shown to be effective for decreasing risk of disease transmission in at-risk populations, and may be well suited for AI/AN injection drug users residing in rural reservation communities. In this study, we aimed to examine the characteristics of American Indians (AI) who use injection drugs (PWUID) in northeastern Montana to identify needs that could be addressed with harm reduction programming.MethodsFor the present study, we used a respondent-driven sampling approach to generate a sample of 51 self-identified male and female injection drug users ≥18 years of age who were American Indians living on the Fort Peck Indian Reservation. Sampling weights were applied to all analyses using Respondent-Driven Sampling Analysis Tool (RDSAT).ResultsThere were no strong recruitment patterns by age, sex, or ethnic identity status of the recruiter or participant, but there were strong within-group recruitment patterns by location within the reservation. The majority of the sample reported initiating substance use before the age of 18. Participants reported significant risk for HIV, hepatitis, and other infectious diseases through their drug use and/or risky sexual behavior. Sixty-five percent reported having reused syringes, and 53% reported drawing from the same filter. Seventy-five percent reported inconsistent condom use during the 3 months preceding the survey, and 53% reported injecting drugs during sex during the 3 months preceding the survey. Only 66% of participants reported having been tested for HIV in the 12 months preceding the survey. The vast majority (98%) of respondents expressed interest in a harm reduction program. Seventy-six percent reported that it was easy or very easy to obtain new syringes.ConclusionsWe documented several risks for blood-borne pathogens, including elevated levels of syringe reuse. Further, we documented significant interest in harm reduction interventions in the present sample of AI/AN injection drug users. Findings suggest a need for increased access to harm reduction programming for AI/AN injection drug users to reduce the transmission of infectious disease and increase access to compassionate care.

Viral hepatitis in female sex workers using the Respondent-Driven Sampling.

ABSTRACTOBJECTIVETo estimate the prevalence of hepatitis B virus and C virus infections and their genotypes and analyze the risk factors for the markers of exposure to hepatitis B virus in female sex workers in a region of intense sex trade.METHODSThis is a cross-sectional study performed with four hundred and two female sex workers in Goiânia, Brazil. Data have been collected using the Respondent-Driven Sampling. The women have been interviewed and tested for markers of hepatitis B and C viruses. Positive samples have been genotyped. The data have been analyzed using the Respondent-Driven Sampling Analysis Tool, version 5.3, and Stata 11.0.RESULTSThe adjusted prevalence for hepatitis B virus and C virus were 17.1% (95%CI 11.6–23.4) and 0.7% (95%CI 0.1–1.5), respectively. Only 28% (95%CI 21.1–36.4) of the participants had serological evidence of vaccination against hepatitis B virus. Being older (> 40 years), being single, having a history of blood transfusion and use of cocaine, and ignoring the symptoms of sexually transmitted infections were associated with positivity for hepatitis B virus (p < 0.05). We have detected the subgenotype A1 of hepatitis B virus (n = 3) and the subtypes of hepatitis C virus 1a (n = 3) and 1b (n = 1).CONCLUSIONSWe can observe a low prevalence of infection of hepatitis B and C viruses in the studied population. However, the findings of the analysis of the risk factors show the need for more investment in prevention programs for sexual and drug-related behavior, as well as more efforts to vaccinate this population against hepatitis B. The genotypes of the hepatitis B virus and C virus identified are consistent with those circulating in Brazil.

HIV prevalence and risk behaviors among people who inject drugs in Songkhla, Thailand: A respondent-driven sampling survey

Background: Songkhla has one of the most serious provincial HIV epidemics among people who inject drugs (PWID). However there remains a lack of systematic data on drug use patterns HIV risk behaviors and access to interventions. To address the gap we conducted an integrated bio-behavioral survey in 2010. Methods: Respondent-driven sampling (RDS) was used to recruit PWID who reported injecting in the last six months. Participants were interviewed and tested for HIV and sexually transmitted infections (STIs). RDS Analysis Tool (RDSAT) was used to generate adjusted proportion estimates. Results: Of 202 participants almost all were men 90% injected heroin followed by methamphetamine (22%). One-third (37%) injected multiple drugs. HIV prevalence was high (22%). Seven percent reported needle sharing at last injection and 27% reported using a condom at last sex. Nearly half (42%) were currently on methadone treatment. Few participants received new needles (10%) and condoms (11%) from drop-in centers and/or peer outreach workers. Conclusion: This RDS survey informs the understanding of the HIV epidemic and the programmatic response among PWID in Songkhla. It was effective at recruiting PWID who were currently out-of-treatment. Given the increasing trend of poly-drug injecting use documented a comprehensive and integrated combination intervention approach for HIV services is recommended. Copyright © 2016 Elsevier B.V.

A single weighting approach to analyze respondent-driven sampling data.

Background and objectives:Respondent-driven sampling (RDS) is widely used to sample hidden populations and RDS data are analyzed using specially designed RDS analysis tool (RDSAT). RDSAT estimates parameters such as proportions. Analysis with RDSAT requires separate weight assignment for individual variables even in a single individual; hence, regression analysis is a problem. RDS-analyst is another advanced software that can perform three methods of estimates, namely, successive sampling method, RDS I and RDS II. All of these are in the process of refinement and need special skill to perform analysis. We propose a simple approach to analyze RDS data for comprehensive statistical analysis using any standard statistical software.Methods:We proposed an approach (RDS-MOD - respondent driven sampling-modified) that determines a single normalized weight (similar to RDS II of Volz-Heckathorn) for each participant. This approach converts the RDS data into clustered data to account the pre-existing relationship between recruits and the recruiters. Further, Taylor's linearization method was proposed for calculating confidence intervals for the estimates. Generalized estimating equation approach was used for regression analysis and parameter estimates of different software were compared.Results:The parameter estimates such as proportions obtained by our approach were matched with those from currently available special software for RDS data.Interpretation & conclusions:The proposed weight was comparable to different weights generated by RDSAT. The estimates were comparable to that by RDS II approach. RDS-MOD provided an efficient and easy-to-use method of estimation and regression accounting inter-individual recruits’ dependence.

Risk factors associated with resistance to HIV testing among transwomen in Brazil

Transwomen are a high-risk population for HIV/AIDS worldwide. However, many transwomen do not test for HIV. This study aimed to identify factors associated with resistance to HIV testing among transwomen in Fortaleza/CE. A cross-sectional study was conducted between August and December 2008 with a sample of 304 transwomen recruited through respondent-driven sampling. Data analysis utilized Respondent-Driven Sampling Analysis Tool and SPSS 11.0. Univariate, bivariate, and multivariate analyses examined risk factors associated with resistance to HIV testing. Less than 18 years of age (OR = 4.221; CI = 2.419–7.364), sexual debut before 10 years of age (OR = 6.760; CI = 2.996–15.256), using illegal drugs during sex (OR = 2.384; CI = 1.310–4.339), experience of discrimination (OR = 3.962; CI = 1.540–10.195) and a belief that the test results were not confidential (OR = 3.763; CI = 2.118–6.688) are independently associated with resistance to testing. Intersectoral and targeted strategies aimed at encouraging the adoption of safer sexual behaviors and testing for HIV among transwomen are required.

Prevalence and Correlates of HIV and Hepatitis C Virus Infections and Risk Behaviors among Malaysian Fishermen.

Fishermen in Southeast Asia have been found to be highly vulnerable to HIV, with research evidence highlighting the role of sexual risk behaviors. This study aims to estimate the rate of HIV as well as hepatitis C virus (HCV) infections among Malaysian fishermen, and the risky sexual and injection drug use behaviors that may contribute to these infections. The study also includes an assessment of socio-demographic, occupational and behavioral correlates of testing positive for HIV or HCV, and socio-demographic and occupational correlates of risk behaviors. The study had a cross-sectional design and recruited 406 fishermen through respondent-driven sampling (RDS). Participants self-completed a questionnaire and provided biological specimens for HIV and HCV testing. We conducted and compared results of analyses of both unweighted data and data weighted with the Respondent-Driven Sampling Analysis Tool (RDSAT). Of the participating fishermen, 12.4% were HIV positive and 48.6% had HCV infection. Contrary to expectations and findings from previous research, most fishermen (77.1%) were not sexually active. More than a third had a history of injection drug use, which often occurred during fishing trips on commercial vessels and during longer stays at sea. Of the fishermen who injected drugs, 42.5% reported unsafe injection practices in the past month. Reporting a history of injection drug use increased the odds of testing HIV positive by more than 6 times (AOR = 6.22, 95% CIs [2.74, 14.13]). Most fishermen who injected drugs tested positive for HCV. HCV infection was significantly associated with injection drug use, being older than 25 years, working on a commercial vessel and spending four or more days at sea per fishing trip. There is an urgent need to strengthen current harm reduction and drug treatment programs for Malaysian fishermen who inject drugs, especially among fishermen who work on commercial vessels and engage in deep-sea fishing.

Prevalence and behavioural risks for HIV and HCV infections in a population of drug users of Dakar, Senegal: the ANRS 12243 UDSEN study.

ObjectivesData on the extent of drug use and associated HIV, hepatitis C and hepatitis B infection in West Africa are lacking. The objectives of ANRS12244 UDSEN study were to estimate the size of the heroin and/or cocaine drug user (DU) population living in the Dakar area (Senegal), and assess the prevalence and risk factors of HIV, hepatitis C virus (HCV) and hepatitis B virus (HBV), including behavioural determinants in this population, in order to set up an integrated prevention and treatment programme for DUs.Design and methodsA capture-recapture method was applied for population size estimation, whereas the respondent-driven sampling (RDS) method was used to recruit a sample of DUs living in the Dakar area and determine HIV, HBV and HCV prevalence. Behavioural data were gathered during face-to-face interviews, and blood samples were collected on dried blood spots for analysis in a central laboratory. Data analysis was performed using the RDS analysis tool, and risk factors were determined by logistic regression. Access to laboratory results was organized for the participants.ResultsThe size of the DU population in the Dakar area was estimated to reach 1324 (95% confidence interval (95% CI: 1281–1367)). Based on the 506 DUs included in the study, the HIV, HCV and HBV prevalence were 5.2% (95% CI: 3.8–6.3), 23.3% (95% CI: 21.2–25.2) and 7.9% (95% CI: 5.2–11.1), respectively. In people who inject drugs (PWID), prevalence levels increased to 9.4% for HIV and 38.9% for HCV (p=0.001 when compared to those who never injected). Women were more at risk of being HIV infected (prevalence: 13.04% versus 2.97% in males, p=0.001). Being PWID was a risk factor for HCV and HIV infection (odds ratio, OR: 2.7, 95% CI: 1.7–4.3, and OR: 4.3, 95% CI: 1.7–10.7, respectively), whereas older age and female sex were additional risk factors for HIV infection (10% increase per year of age, p=0.03 and OR: 4.9, 95% CI: 1.6–156, respectively). No specific determinant was associated with the risk of HBV infection.ConclusionsHigh HIV and HCV prevalence were estimated in this population of DUs (including non-injectors) living in the Dakar area, Senegal, whereas HBV prevalence was close to that of the global Senegalese population, reflecting a risk of infection independent of drug use. Women seem to be highly vulnerable and deserve targeted interventions for decreasing exposure to HIV, while behavioural risk factors for HIV and HCV include the use of unsafe injections, reflecting the urgent need for developing harm reduction interventions and access to opioid substitution therapy services.

Population size, HIV, and behavior among MSM in Luanda, Angola: challenges and findings in the first ever HIV and syphilis biological and behavioral survey.

To conduct the first population size estimation and biological and behavioral surveillance survey among men who have sex with men (MSM) in Angola. Population size estimation with multiplier method and a cross-sectional study using respondent-driven sampling. Luanda Province, Angola. Study was conducted in a large hospital. Seven hundred ninety-two self-identified MSM accepted a unique object for population size estimation. Three hundred fifty-one MSM were recruited with respondent-driven sampling for biological and behavioral surveillance survey. Interviews and testing for HIV and syphilis were conducted on-site. Analysis used Respondent-Driven Sampling Analysis Tool and STATA 11.0. Univariate, bivariate, and multivariate analyses examined factors associated with HIV and unprotected sex. Six imputation strategies were used for missing data for those refusing to test for HIV. A population size of 6236 MSM was estimated. Twenty-seven of 351 individuals were tested positive. Adjusted HIV prevalence was 3.7% (8.7% crude). With imputation, HIV seroprevalence was estimated between 3.8% [95% confidence interval (CI): 1.6 to 6.5] and 10.5% (95% CI: 5.6 to 15.3). Being older than 25 (odds ratio = 10.8, 95% CI: 3.5 to 32.8) and having suffered episodes of homophobia (odds ratio = 12.7, 95% CI: 3.2 to 49.6) significantly increased the chance of HIV seropositivity. Risk behaviors are widely reported, but HIV seroprevalence is lower than expected. The difference between crude and adjusted values was mostly due to treatment of missing values in Respondent-Driven Sampling Analysis Tool. Solutions are proposed in this article. Although concerns were raised about feasibility and adverse outcomes for MSM, the study was successfully and rapidly completed with no adverse effects.

HIV, syphilis and sexual risk behaviours among men who have sex with men in Agadir and Marrakesh, Morocco

ObjectiveTo collect baseline measurements of HIV and syphilis prevalence and sexual risk behaviours among men who have sex with men (MSM) in Agadir and Marrakech, Morocco, and provide strategic information...

The Importance of Measuring and Accounting for Potential Biases in Respondent-Driven Samples

Respondent-driven sampling (RDS) is often viewed as a superior method for recruiting hard-to-reach populations disproportionately burdened with poor health outcomes. As an analytic approach, it has been praised for its ability to generate unbiased population estimates via post-stratified weights which account for non-random recruitment. However, population estimates generated with RDSAT (RDS Analysis Tool) are sensitive to variations in degree weights. Several assumptions are implicit in the degree weight and are not routinely assessed. Failure to meet these assumptions could result in inaccurate degree measures and consequently result in biased population estimates. We highlight potential biases associated with violating the assumptions implicit in degree weights for the RDSAT estimator and propose strategies to measure and possibly correct for biases in the analysis.

Predictors of Inconsistent Condom Use among a Hard to Reach Population of Young Women with Multiple Sexual Partners in Peri-Urban South Africa

BackgroundEvidence suggests that multiple concurrent sexual partnering may be a key driver of the high HIV prevalence among young women in South Africa. However, little is known about whether and to what extent women who have multiple sexual partners also engage in other high risk sexual behaviors such as inconsistent condom use. And yet, multiple concurrent sexual partnering is of little epidemiological relevance if all partners in these sexual networks use condoms consistently. This study assesses the prevalence of sexual risk behaviors and HIV, and predictors of inconsistent condom use among women aged 16–24 with multiple sexual partners in a peri-urban setting in South Africa.MethodsWe used Respondent Driven Sampling, a sampling strategy for hard-to-reach populations to recruit 259 women aged 16–24 in a bio-behavioral cross-sectional survey in the Western Cape province. Estimates of population proportions and 95% confidence intervals (CIs) were calculated using the Respondent-Driven Sampling Analysis Tool 5.6 (RDSAT). The primary outcome was inconsistent condom use in the past three months.ResultsYoung women reported an average of 7 partners in the past 3 months and a high prevalence of sexual risk behaviors: concurrency (87%), transactional sex (91%) and age mixing (59%). Having >5 sexual partners in the last 3 months doubled the risk of unprotected sex (OR 2.43, CI 1.39–4.25). HIV prevalence was 4% among 16–19 year olds, increasing threefold (12%) at age 20–24.DiscussionMultiple sexual partnering, where a high number of partners are acquired in a short space of time, is a fertile context for unprotected and risky sexual behavior. The young women featured in this survey present with a constellation of high-risk sexual behaviors that cluster to form a risk syndrome. Carefully tailored repeat bio-behavioral surveillance surveys are recommended for this sub-population.

Prevalence of HIV and sexually transmitted infections and patterns of recent HIV testing among men who have sex with men in Zagreb, Croatia

ObjectiveTo determine the prevalence of HIV and other sexually transmitted infections (STIs) among men who have sex with men (MSM) in Zagreb, Croatia, and assess correlates of testing for HIV...

Depressive symptoms and associated sexual behaviors among men who have sex with men in Foshan, Guangdong province

To understand the prevalence of depressive symptoms and associated sexual characteristics among men who have sex with men (MSM) in Foshan, Guangdong province. Respondent-driven sampling method was used to recruit MSM who were 18 years and older, living in Foshan longer than 6 months. Scales of depression, demographical information, and characteristics of sexual behaviors were collected using a self-designed questionnaire. Respondent-Driven Sampling Analysis Tool and SAS were used to generate crude and estimated population proportion as well as 95% confidence intervals (CI). Multivariate logistic regression was performed to explore potential factors associated with depressive symptoms. Among 249 respondents, the mean age (standard deviation) was 31.9 (8.5) years, with 43.5% of them having had 7-9 years of education while 25.9% had 10-12 years. 49.7% of the respondents were currently married. 56.7% of them had bisexual orientation. 42.3% of them met their sex partners in parks/toilet and 63.3% of them had their first sex with a female. The estimated prevalence of depressive symptoms was 34.8% (28.2-42.3) among MSM in Foshan. Younger age, lower education levels, only had oral sex, and regularly meeting sexual partners in parks were associated with depressive symptoms, with the adjusted odd ratio (95%CI) as 3.31 (1.39-7.86), 2.23 (1.01-4.93), 3.09 (1.10-8.70) and 2.38 (1.20-4.75), respectively. Depression related symptoms might associate with the demographical and sexual characteristics of MSM in Foshan, suggesting that psychological interventions should involve components as demographical and sexual characteristics.

Consistently Low Prevalence of Syphilis among Female Sex Workers in Jinan, China: Findings from Two Consecutive Respondent Driven Sampling Surveys

BackgroundRoutine surveillance using convenient sampling found low prevalence of HIV and syphilis among female sex workers in China. Two consecutive surveys using respondent driven sampling were conducted in 2008 and 2009 to examine the prevalence of HIV and syphilis among female sex workers in Jinan, China.MethodsA face-to-face interview was conducted to collect demographic, behavioral and service utilization information using a structured questionnaire. Blood samples were drawn for serological tests of HIV-1 antibody and syphilis antibody. Respondent Driven Sampling Analysis Tool was used to generate population level estimates.ResultsIn 2008 and in 2009, 363 and 432 subjects were recruited and surveyed respectively. Prevalence of syphilis was 2.8% in 2008 and 2.2% in 2009, while no HIV case was found in both years. Results are comparable to those from routine sentinel surveillance system in the city. Only 60.8% subjects in 2008 and 48.3% in 2009 reported a consistent condom use with clients during the past month. Over 50% subjects had not been covered by any HIV-related services in the past year, with only 15.6% subjects in 2008 and 13.1% in 2009 ever tested for HIV.ConclusionsDespite the low prevalence of syphilis and HIV, risk behaviors are common. Targeted interventions to promote the safe sex and utilization of existing intervention services are still needed to keep the epidemic from growing.

P1-S2.23 Transgender persons in Guatemala - over-exposed and under-protected - the findings of an RDS behavioural survey

BackgroundMale-to-female transgender persons experience the highest HIV prevalence rates of any high risk population in Central America. The purpose of this study is to compare HIV-related risk behaviours, knowledge and exposure to prevention activities among transgender persons and other men who have sex with men (MSM) in Guatemala City.MethodsFrom September—to December 2010, we conducted a probability-based survey of MSM, including male-to-female transgender persons who have sex with men, using respondent-driven sampling (RDS) in Guatemala City. Data on sexual and drug use behaviour, knowledge of HIV, attitudes, stigma, access to prevention, care, and treatment services were collected by interviewers using Personal Digital Assistants (PDA). Population proportions and 95% CIs, adjusted for RDS sampling weights, were calculated using the Respondent Driven Sampling Analysis Tool (version 6.0). Crude summary statistics were calculated in SAS (version 9.1).ResultsA total of 509 MSM, including 99 male-to-female transgender persons enrolled in the study. The mean age for transgendered persons was 29.1 vs 28.0 for non-transgender MSM. Education level and socio-economic status were comparable between the two groups. Transgender persons, in comparison to non-transgender MSM, had higher rates of transactional sex (77.6% vs 41.9% in the past year, respectively), drug use (26.7% vs 3.3% cocaine use in the past month) and prior HIV testing (95.7% vs 68.9%, during lifetime). On the other hand, transgender persons have similar levels of forced sex (14.1% vs 6.5% in the past year), exposure to HIV educational activities (74.2% to 67.8% in the past year), access to free condoms (83.9% to 79.6%) and correct knowledge of HIV prevention (54.8% vs 41.7%) see Abstract P1-S2.23 Figure 1. Conclusions—Compared to other MSM, transgender persons in Guatemala City more often receive money for sex and use cocaine and are at disproportionately higher risk for HIV infection. While prevention activities, such as HIV testing, seem to be reaching transgender persons, exposure may not translate into increased protection. Findings emphasise the need for innovative HIV prevention activities to address the many facets and levels of vulnerability and social marginalisation experienced by transgender persons in Guatemala City. Such efforts should extend beyond individual-level outreach and information provision to rigorously evaluated intervention strategies at the social and structural levels.Abstract P1-S2.23 Figure 1Behavioural and HIV Prevention Indicators. Non-transgender MSM and Transgender Persons, Guatemala City, 2010.