共查询到20条相似文献，搜索用时 31 毫秒
1.
Background
Compared to the general population, men who have sex with men (MSM) are at greater risk for HIV and less understood due to their more hidden and stigmatized nature. Moreover, the discrepancy in findings in the literature merits further investigations in MSM populations from different cultures and settings. We therefore conducted this study to explore factors associated with inconsistent condom use among high-risk MSM in Cambodia.Methods
This cross-sectional study was conducted in 2014 among 367 MSM randomly selected from Battembang and Siem Reap using a two-stage cluster sampling method. A structured questionnaire was used for face-to-face interviews to collect information on characteristics of respondents, HIV testing history, self-perception of HIV risk, substance use, sexual behaviors, mental disorders, and HIV knowledge. Multivariable logistic regression analysis was performed to identify factors independently associated with inconsistent condom use.Results
On average, 62.3% of respondents reported that they always used condoms over the past three months. The rates varied with types of sexual partners; the proportion of respondents who reported always using condoms was 55.1%, 64.2%, 75.9%, 73.0%, 78.1%, and 70.3%, for sexual partners who were girlfriends, boyfriends, female sex workers, male sex workers, female clients, or male clients, respectively. After adjustment, inconsistent condom use was significantly associated with age of ≥25 (AOR = 1.77, 95% CI = 1.09–2.86), self-rated quality of life as good or very good (AOR = 4.37, 95% CI = 1.79–5.67), self-perception of higher HIV risk compared to the general population (AOR = 2.37, 95% CI = 1.35–4.17), illicit drug use in the past three months (AOR = 5.76, 95% CI = 1.65–10.09), and reported consistent lubricant use when selling anal sex to men in the past three months (AOR = 2.85, 95% CI = 1.07–8.12).Conclusions
We found risky sexual behaviors to be considerably high among MSM in this study, especially among those who used illicit drugs or were older than 25. HIV education and social marketing should be expanded and specifically designed for MSM to better educate on the increased risk of HIV with unprotected anal sex and illicit drug use as risk factors, and the importance of the use of both condoms and lubricant during anal intercourse. 相似文献2.
Hong-Van Tieu Ting-Yuan Liu Sophia Hussen Matthew Connor Lei Wang Susan Buchbinder Leo Wilton Pamina Gorbach Kenneth Mayer Sam Griffith Corey Kelly Vanessa Elharrar Gregory Phillips Vanessa Cummings Beryl Koblin Carl Latkin HPTN 《PloS one》2015,10(8)
Background
Sexual networks may place U.S. Black men who have sex with men (MSM) at increased HIV risk.Methods
Self-reported egocentric sexual network data from the prior six months were collected from 1,349 community-recruited Black MSM in HPTN 061, a multi-component HIV prevention intervention feasibility study. Sexual network composition, size, and density (extent to which members are having sex with one another) were compared by self-reported HIV serostatus and age of the men. GEE models assessed network and other factors associated with having a Black sex partner, having a partner with at least two age category difference (age difference between participant and partner of at least two age group categories), and having serodiscordant/serostatus unknown unprotected anal/vaginal intercourse (SDUI) in the last six months.Results
Over half had exclusively Black partners in the last six months, 46% had a partner of at least two age category difference, 87% had ≤5 partners. Nearly 90% had sex partners who were also part of their social networks. Among HIV-negative men, not having anonymous/exchange/ trade partners and lower density were associated with having a Black partner; larger sexual network size and having non-primary partners were associated with having a partner with at least two age category difference; and having anonymous/exchange/ trade partners was associated with SDUI. Among HIV-positive men, not having non-primary partners was associated with having a Black partner; no sexual network characteristics were associated with having a partner with at least two age category difference and SDUI.Conclusions
Black MSM sexual networks were relatively small and often overlapped with the social networks. Sexual risk was associated with having non-primary partners and larger network size. Network interventions that engage the social networks of Black MSM, such as interventions utilizing peer influence, should be developed to address stable partnerships, number of partners, and serostatus disclosure. 相似文献3.
Geneviève A. F. S. van Liere Jeanne A. M. C. Dirks Christian J. P. A. Hoebe Petra F. Wolffs Nicole H. T. M. Dukers-Muijrers 《PloS one》2015,10(8)
Background
Anorectal Chlamydia trachomatis (chlamydia) is frequently diagnosed in men who have sex with men (MSM) and in women, but it is unknown whether these infections are comparable in clinical impact and transmission potential. Quantifying bacterial load and identifying determinants associated with high bacterial load could provide more insight.Methods
We selected a convenience sample of MSM who reported anal sex (n = 90) and women with concurrent urogenital/anorectal chlamydia who reported anal sex (n = 51) or did not report anal sex (n = 61) from the South Limburg Public Health Service’s STI unit. Bacterial load (Chlamydia/ml) was quantified for all samples and log transformed for analyses. Samples with an unquantifiable human leukocyte antigen (n = 9) were excluded from analyses, as they were deemed inadequately sampled.Results
The mean log anorectal chlamydia load (3.50) was similar for MSM and women who reported having anal sex (3.80, P = 0.21). The anorectal chlamydia load was significantly higher in these groups than in women who did not report having anal sex (2.76, P = 0.001). Detectable load values ranged from 1.81–6.32 chlamydia/ml for MSM, 1.74–7.33 chlamydia/ml for women who reported having anal sex and 1.84–6.31 chlamydia/ml for women who did not report having anal sex. Symptoms and several other determinants were not associated with anorectal chlamydia load.Conclusions
Women who did not report anal sex had lower anorectal loads, but they were within a similar range to the other two groups. Anorectal chlamydia load was comparable between MSM and women who reported anal sex, suggesting similar transmission potential. 相似文献4.
M Berry AL Wirtz A Janayeva V Ragoza A Terlikbayeva B Amirov S Baral C Beyrer 《PloS one》2012,7(8):e43071
Introduction
Men who have sex with men (MSM) are at high risk for HIV infection. MSM in Central Asia, however, are not adequately studied to assess their risk of HIV transmission. Methods: This study used respondent driven sampling methods to recruit 400 MSM in Almaty, the largest city in Kazakhstan, into a cross-sectional study. Participation involved a one-time interviewer-administered questionnaire and rapid HIV screening test. Prevalence data were adjusted for respondent network size and recruitment patterns. Multivariate logistic regression was used to investigate the association between HIV and selected risk factors, and unprotected anal intercourse (UAI) and selected risk factors.Results
After respondent driven sampling (RDS) weighted analysis, 20.2% of MSM were HIV-positive, and 69.0% had unprotected sex with at least one male partner in the last 12 months. Regression analysis showed that HIV infection was associated with unprotected receptive anal sex (AOR: 2.00; 95% CI: 1.04–3.84). Having unprotected anal intercourse with male partners, a measure of HIV risk behaviors, was associated with being single (AOR: 0.38; 95% CI: 0.23–0.64); very difficult access to lubricants (AOR: 11.08; 95% CI: 4.93–24.91); STI symptoms (AOR: 3.45; 95% CI: 1.42–8.40); transactional sex (AOR: 3.21; 95% CI: 1.66–6.22); and non-injection drug use (AOR: 3.10; 95% CI: 1.51–6.36).Conclusions
This study found a high HIV prevalence among MSM in Almaty, and a population of MSM engaging in multiple high-risk behavior in Almaty. Greater access to HIV education and prevention interventions is needed to limit the HIV epidemic among MSM in Almaty. 相似文献5.
Hilary K. Hsu Todd T. Brown Xiuhong Li Stephen Young Ross D. Cranston Gypsyamber D’Souza Lisa P. Jacobson Otoniel Martínez-Maza Eric C. Seaberg Joseph B. Margolick Frank J. Jenkins Matthew G. Moran Kristofer Chua Robert K. Bolan Roger Detels Dorothy J. Wiley 《PloS one》2015,10(3)
Background
Human papillomavirus (HPV) types 16 and 18 cause invasive cervical cancer and most invasive anal cancers (IACs). Overall, IAC rates are highest among men who have sex with men (MSM), especially MSM with HIV infection. Testosterone is prescribed for men showing hypogonadism and HIV-related wasting. While there are direct and indirect physiological effects of testosterone in males, its role in anal HPV16/18 infections in men is unknown.Methods
Free testosterone (FT) was measured in serum from 340 Multicenter AIDS Cohort Study (MACS) participants who were tested for anal HPV16/18-DNA approximately 36 months later. The effect of log10-transformed current FT level on anal HPV16/18 prevalence was modeled using Poisson regression with robust error variance. Multivariate models controlled for other HPV types, cumulative years of exogenous testosterone use, race, age, lifetime number of receptive anal intercourse partnerships, body mass index, tobacco smoking, HIV-infection and CD4+ T-cell counts among HIV-infected, and blood draw timing.Results
Participants were, on average, 60 (+5.4) years of age, White (86%), and HIV-uninfected (56%); Twenty-four percent tested positive for anal HPV16 and/or 18-DNA (HPV16 prevalence=17.1%, HPV18=9.1%). In adjusted analysis, each half-log10 increase of FT was associated with a 1.9-fold (95% Confidence Interval: 1.11, 3.24) higher HPV16/18 prevalence. Additionally, other Group 1 high-risk HPVs were associated with a 1.56-fold (1.03, 2.37) higher HPV16/18 prevalence. Traditional risk factors for HPV16/18 infection (age, tobacco smoking; lifetime number of sexual partners, including the number of receptive anal intercourse partnerships within 24 months preceding HPV testing) were poorly correlated with one another and not statistically significantly associated with higher prevalence of HPV16/18 infection in unadjusted and adjusted analyses.Conclusions
Higher free testosterone was associated with increased HPV16/18 prevalence measured approximately three years later, independent of sexual behavior and other potential confounders. The mechanisms underlying this association remain unclear and warrant further study. 相似文献6.
Mary C. Cambou Amaya G. Perez-Brumer Eddy R. Segura H. Javier Salvatierra Javier R. Lama Jorge Sanchez Jesse L. Clark 《PloS one》2014,9(7)
Background
Partnership type is an important factor associated with unprotected anal intercourse (UAI) and subsequent risk for HIV and sexually transmitted infections (STI). We examined the association of partnership type with UAI among men who have sex with men (MSM) and male-to-female transgender women (TGW) in Lima, Peru, recently diagnosed with HIV and/or STI.Methods
We report data from a cross-sectional analysis of MSM and TGW recently diagnosed with HIV and/or STI in Lima, Peru between 2011 and 2012. We surveyed participants regarding UAI with up to their three most recent sexual partners according to partner type. Multivariable Generalized Estimate Equating (GEE) models with Poisson distribution were used to estimate prevalence ratios (PR) for UAI according to partner type.Results
Among 339 MSM and TGW recently diagnosed with HIV and/or STI (mean age: 30.6 years, SD 9.0), 65.5% self-identified as homosexual/gay, 16.0% as bisexual, 15.2% as male-to-female transgender, and 3.3% as heterosexual. Participants provided information on 893 recent male or TGW partners with whom they had engaged in insertive or receptive anal intercourse: 28.9% stable partners, 56.4% non-stable/non-transactional partners (i.e. casual or anonymous), and 14.7% transactional partners (i.e. transactional sex client or sex worker). Unprotected anal intercourse was reported with 41.3% of all partners. In multivariable analysis, factors associated with UAI included partnership type (non-stable/non-transactional partner APR 0.73, [95% CI 0.59–0.91], transactional partner APR 0.53 [0.36–0.78], p<0.05) and the number of previous sexual encounters with the partner (>10 encounters APR 1.43 [1.06–1.92], p<0.05).Conclusion
UAI was more commonly reported for stable partners and in partnerships with >10 sexual encounters, suggesting UAI is more prevalent in partnerships with a greater degree of interpersonal commitment. Further research assessing partner-level factors and behavior is critical for improving HIV and/or STI prevention efforts among Peruvian MSM and TGW. 相似文献7.
Snigdha Vallabhaneni J. Jeff McConnell Lisa Loeb Wendy Hartogensis Fredrick M. Hecht Robert M. Grant Christopher D. Pilcher 《PloS one》2013,8(2)
Objective
We assessed changes in sexual behavior among men who have sex with men (MSM), before and for several years after HIV diagnosis, accounting for adoption of a variety of seroadaptive practices.Methods
We collected self-reported sexual behavior data every 3 months from HIV-positive MSM at various stages of HIV infection. To establish population level trends in sexual behavior, we used negative binomial regression to model the relationship between time since diagnosis and several sexual behavior variables: numbers of (a) total partners, (b) potentially discordant partners (PDP; i.e., HIV-negative or unknown-status partners), (c) PDPs with whom unprotected anal intercourse (UAI) occurred, and (d) PDPs with whom unprotected insertive anal intercourse (uIAI) occurred.Results
A total of 237 HIV-positive MSM contributed 502 interviews. UAI with PDPs occurred with a mean of 4.2 partners in the 3 months before diagnosis. This declined to 0.9 partners/3 months at 12 months after diagnosis, and subsequently rose to 1.7 partners/3 months at 48 months, before falling again to 1.0 partners/3 months at 60 months. The number of PDPs with whom uIAI occurred dropped from 2.4 in the pre-diagnosis period to 0.3 partners/3 months (an 87.5% reduction) by 12 months after enrollment, and continued to decline over time.Conclusion
Within months after being diagnosed with HIV, MSM adopted seroadaptive practices, especially seropositioning, where the HIV-positive partner was not in the insertive position during UAI, resulting in a sustained decline in the sexual activity associated with the highest risk of HIV transmission. 相似文献8.
9.
DeMarc A. Hickson Nhan L. Truong Neena Smith-Bankhead Nikendrick Sturdevant Dustin T. Duncan Jordan Schnorr June A. Gipson Leandro A. Mena 《PloS one》2015,10(12)
Background
This paper describes the rationale, design, and methodology of the Ecological Study of Sexual Behaviors and HIV/STI among African American Men Who Have Sex with Men (MSM) in the Southeastern United States (U.S.; known locally simply as the MARI Study).Methods
Participants are African American MSM aged 18 years and older residing in the deep South.Results
Between 2013 and 2015, 800 African American MSM recruited from two study sites (Jackson, MS and Atlanta, GA) will undergo a 1.5-hour examination to obtain anthropometric and blood pressure measures as well as to undergo testing for sexually transmitted infections (STI), including HIV. Intrapersonal, interpersonal, and environmental factors are assessed by audio computer-assisted self-interview survey. Primary outcomes include sexual risk behaviors (e.g., condomless anal sex) and prevalent STIs (HIV, syphilis, gonorrhea, and Chlamydia).Conclusion
The MARI Study will typify the HIV environmental ''riskscape'' and provide empirical evidence into novel ecological correlates of HIV risk among African American MSM in the deep South, a population most heavily impacted by HIV. The study''s anticipated findings will be of interest to a broad audience and lead to more informed prevention efforts, including effective policies and interventions, that achieve the goals of the updated 2020 U.S. National HIV/AIDS Strategy. 相似文献10.
Background
Despite preventive efforts, HIV incidence remains high among men who have sex with men (MSM) in industrialized countries. Condoms are an important element in prevention but, given the high frequency of condom use and their imperfect effectiveness, a substantial number and proportion of HIV transmissions may occur despite condoms. We developed a model to examine this hypothesis.Methods
We used estimates of annual prevalent and incident HIV infections for MSM in Ontario. For HIV-negative men, we applied frequencies of sexual episodes and per-contact HIV transmission risks of receptive and insertive anal sex with and without a condom and oral sex without a condom. We factored in the proportion of HIV-infected partners receiving antiretroviral therapy and its impact in reducing transmissibility. We used Monte-Carlo simulation to determine the plausible range for the proportion of HIV transmissions for each sexual practice.Results
Among Ontario MSM in 2009, an estimated 92,963 HIV-negative men had 1,184,343 episodes of anal sex with a condom and 117,133 anal sex acts without a condom with an HIV-positive partner. Of the 693 new HIV infections, 51% were through anal sex with a condom, 33% anal sex without a condom and 16% oral sex. For anal sex with a condom, the 95% confidence limits were 17% and 77%.Conclusions
The proportion of HIV infections related to condom failure appears substantial and higher than previously thought. That 51% of transmissions occur despite condom use may be conservative (i.e. low) since we used a relatively high estimate (87.1%) for condom effectiveness. If condom effectiveness were closer to 70%, a value estimated from a recent CDC study, the number and proportion of HIV transmissions occurring despite condom use would be much higher. Therefore, while condom use should continue to be promoted and enhanced, this alone is unlikely to stem the tide of HIV infection among MSM. 相似文献11.
Jinlei Qi Dapeng Zhang Xiaojing Fu Chengmei Li Sining Meng Min Dai Hui Liu Jiangping Sun 《PloS one》2015,10(4)
Objective
While the HIV epidemic varies greatly by region and population group throughout China, the HIV incidence among men who have sex with men (MSM) continues to rise at an alarmingly fast pace. We seek to analyze the risk factors associated with HIV infection among MSM recruited from different channels in large urban centers across China, in an attempt to shed light on the design of future targeted intervention strategies.Methods
A total of 33,684 MSM from 14 cities and one province were recruited from July to December 2011. Demographic (e.g. age, marital status, education) and behavioral (e.g. condom use, HIV testing history) data were collected using information collection cards. Blood samples were also collected to test for HIV and Syphilis.Results
Participants were recruited from five different channels, and all demonstrated distinct characteristics. The overall rate of positive HIV screening was 6.27% and the rate of syphilis infection was 6.50%. Participants recruited from bathhouses had the highest HIV (11.80%) and syphilis infection rates (11.20%). Participants who were infected with syphilis had the highest HIV-positive screening rate (13.75%; 95% CI OR, 2.33-3.06). living in the southwest region of the country (11.64%; OR=2.76, 95%CI OR 2.19-3.47), Being >20 years of age (P<0.001), living in the southwest region of the country (OR=2.76, 95%CI 2.19-3.47), not having sex with female over the previous 3 months (OR=1.27, 95%CI 1.09-1.48), no condom use during the last anal intercourse (OR=1.54, 95%CI 1.39-1.70) and other factors were all associated with a higher probability of having an HIV-positive test result.Conclusion
Depending on the way they are recruited, more targeted interventions are required to prevent the spread of HIV/AIDS among MSM with different characteristics and behaviors. Results from this study could provide evidence for researchers to conduct further studies and policy-makers to establish more effective and strategic interventions for MSM in China. 相似文献12.
Olivier Richel Henry J. C. De Vries Marcel G. W. Dijkgraaf Carel J. M. Van Noesel Jan M. Prins 《PloS one》2013,8(12)
Objective
Anal Intraepithelial Neoplasia (AIN) is present in the majority of HIV+ men who have sex with men (MSM) and routine AIN-screening is subject of discussion. In this study we analysed a wide range of potential risk factors for AIN in order to target screening programs.Methods
We screened 311 HIV+ MSM by high resolution anoscopy, with biopsies of suspect lesions. HIV-parameters, previous sexual transmitted infections (STI’s), anal pathology, sexual practices and substance use were analysed in relation to AIN by uni- and multivariable logistic regression.Results
AIN (any grade) was found in 175/311 MSM (56%), high grade (HG)AIN in 30%. In the univariable analysis, years since HIV diagnosis, years of antiretroviral therapy (cART) and anal XTC use decreased AIN risk, while a history of anogenital warts and use of GHB (γ-hydroxybutyric acid) increased this risk. In the multivariable analysis three parameters remained significant: years of cART (OR=0.92 per year, p=0.003), anal XTC use (OR=0.10, p=0.002) and GHB use (OR=2.60, p=0.003). No parameters were significantly associated with HGAIN, but there was a trend towards increased risk with anal enema use prior to sex (>50 times ever; p=0.07) and with a history of AIN (p=0.06). CD4 count, STI’s, anal pathology, smoking, number of sex partners and anal fisting were not associated with (HG)AIN.Conclusion
GHB use increases the risk for AIN, while duration of cART and anal XTC use are negatively correlated with AIN. Given the high prevalence of AIN in HIV+ MSM, these associations are not helpful to guide a screening program. 相似文献13.
Ana Paula Silva Marília Greco Maria Arlene Fausto Dirceu B. Greco Mariangela Carneiro 《PloS one》2014,9(10)
Background
There has recently been an increase in HIV infection rates among men who have sex with men (MSM). This study aimed at investigating risk factors associated with incident HIV infection in a MSM cohort–Project Horizonte, Belo Horizonte, Minas Gerais, Brazil.Methodology
This is a nested case-control study in an ongoing open cohort of homosexual and bisexual men, carried out in 1994–2010, during which 1,085 volunteers were enrolled. Each HIV seroconverted volunteer (case) was compared with three randomly selected HIV negative controls, matched by admission date and age (±3 years). During follow-up, 93 volunteers seroconverted and were compared with 279 controls.Principal Findings
The risk factors associated with HIV seroconversion were: contact with partner’s blood during sexual relations (OR 3.7; 95% CI 1.2–11.6), attendance at gay saunas in search for sexual partners (OR 2.6; 95% CI 1.3–5.4), occasional intake of alcohol when flirting and engaging in sexual activity (OR 2.5; 95% CI 1.3–5.1), inconsistent use of condoms in receptive anal sex (OR 2.4; 95% CI 1.1–5.4), little interest to look up information about AIDS (OR 2.6; 95% CI 1.0–6.7) particularly in newspapers (OR 3.4; 95% CI 1.4–8.1).Conclusions
This study shows that MSM are still engaging in risk behavior, such as unprotected anal intercourse, despite taking part in a cohort study on various preventive measures. New preventive strategies in touch with the epidemic’s development and the specificities of this particular population are needed. 相似文献14.
Zhen Li Haoran Zhang Xiangwei Li Yu Yang Henan Xin Mufei Li Boxuan Feng Lei Gao 《PloS one》2015,10(4)
Background
Anal human papillomavirus (HPV) infection and its related diseases are relatively common in men who have sex with men (MSM), especially in those HIV positive. In China, molecular epidemiology of anal HPV infection among HIV-positive MSM has been sparsely studied.Methods
A cross-sectional study was conducted among HIV-positive MSM in Xi’an, China between April and July 2014. Anal swabs were collected for HPV genotyping.Results
A total of 195 HIV-positive MSM were included in this study. HPV genotyping showed that 99.0% (191/193) of participants were positive for at least one of the targeted 37 HPV genotypes. 183 (94.8%) of them were infected with multiple high-risk types and 154 (79.8%) of them with low-risk HPV types. HPV 18 was the most frequently identified high-risk type, followed by HPV 16 and HPV 51. As for low-risk types, HPV11, HPV 6 and HPV 81 were most commonly observe. High-risk HPV infection was found to be associated with the status of antiretroviral therapy (ART), the distribution of low-risk types was observed to be varied by CD4+ T cell level.Conclusion
Almost all HIV-positive MSM were anal HPV infected in our study. It is highly recommended to consider regular active screening and preventive intervention of HPV infection among this high risk population. 相似文献15.
Enrique Casalino Christophe Choquet Agathe Leleu Romain Hellmann Mathias Wargon Gaelle Juillien Yazdan Yazdanpanah Elisabeth Bouvet 《PloS one》2014,9(8)
Objective
We aimed to determine the trends in numbers and percentages of sexually exposed persons to HIV (SE) consulting an ED for post-exposure prophylaxis (PEP), as well as predictors of condom use.Study Design
We conducted a prospective-observational study.Methods
We included all SE attendances in our Emergency Department (ED) during a seven-year study-period (2006–2012). Trends were analyzed using time-series analysis. Logistic Regression was used to define indicators of condom use.Results
We enrolled 1851 SE: 45.7% reported intercourse without condom-use and 12.2% with an HIV-infected partner. Significant (p<0.01) rising trends were observed in the overall number of SE visits (+75%), notably among men having sex with men (MSM) (+126%). There were rising trends in the number and percentage of those reporting intercourse without condom-use in the entire population +91% (p<0.001) and +1% (p>0.05), in MSM +228% (p<0.001) and +49% (p<0.001), in Heterosexuals +68% (p<0.001) and +10% (p = 0.08). Among MSM, significant rising trends were found in those reporting high-risk behaviours: anal receptive (+450% and +76%) and anal insertive (+l33% and +70%) intercourses. In a multivariate logistic regression analysis, heterosexuals, vaginal intercourse, visit during the night-shift and short time delay between SE and ED visit, were significantly associated with condom-use.Conclusion
We report an increasing trend in the number of SE, mainly among MSM, and rising trends in high-risk behaviours and unprotected sexual intercourses among MSM. Our results indicate that SE should be considered as a high-risk population for HIV and sexually transmitted diseases. 相似文献16.
Zehava Grossman Boaz Avidor Zohar Mor Michal Chowers Itzchak Levy Eduardo Shahar Klaris Riesenberg Zev Sthoeger Shlomo Maayan Wei Shao Margalit Lorber Karen Olstein-Pops Daniel Elbirt Hila Elinav Ilan Asher Diana Averbuch Valery Istomin Bat Sheva Gottesman Eynat Kedem Shirley Girshengorn Zipi Kra-Oz Yonat Shemer Avni Sara Radian Sade Dan Turner Frank Maldarelli 《PloS one》2015,10(8)
Background
HIV in Israel started with a subtype-B epidemic among men who have sex with men, followed in the 1980s and 1990s by introductions of subtype C from Ethiopia (predominantly acquired by heterosexual transmission) and subtype A from the former Soviet Union (FSU, most often acquired by intravenous drug use). The epidemic matured over the last 15 years without additional large influx of exogenous infections. Between 2005 and 2013 the number of infected men who have sex with men (MSM) increased 2.9-fold, compared to 1.6-fold and 1.3-fold for intravenous drug users (IVDU) and Ethiopian-origin residents. Understanding contemporary spread is essential for effective public health planning.Methods
We analyzed demographic and virologic data from 1,427 HIV-infected individuals diagnosed with HIV-I during 1998–2012. HIV phylogenies were reconstructed with maximum-likelihood and Bayesian methods.Results
Subtype-B viruses, but not A or C, demonstrated a striking number of large clusters with common ancestors having posterior probability ≥0.95, including some suggesting presence of transmission networks. Transmitted drug resistance was highest in subtype B (13%). MSM represented a frequent risk factor in cross-ethnic transmission, demonstrated by the presence of Israeli-born with non-B virus infections and FSU immigrants with non-A subtypes.Conclusions
Reconstructed phylogenetic trees demonstrated substantial grouping in subtype B, but not in non-MSM subtype-A or in subtype-C, reflecting differences in transmission dynamics linked to HIV transmission categories. Cross-ethnic spread occurred through multiple independent introductions, with MSM playing a prevalent role in the transmission of the virus. Such data provide a baseline to track epidemic trends and will be useful in informing and quantifying efforts to reduce HIV transmission. 相似文献17.
Thomas M. Lampinen Keith Chan Robert S. Remis Maraki Fikre Merid Melanie Rusch Jean Vincelette Ken Logue Vladimir Popovic Michel Alary Martin T. Schechter Robert S. Hogg 《CMAJ》2005,172(4):479-483
Background
Phase I and phase II HIV-1 vaccine trials have revealed increases in risky sexual activity among study subjects during the trials, perhaps because the subjects believe that the vaccine being tested is efficacious; subjects may thus suffer harm from their participation. We evaluated the sexual behaviour of Canadian men who have sex with men (MSM) who participated in the phase III Vax004 trial of an HIV-1 vaccine.Methods
Using self-reports of sexual behaviours during the 6 months before trial entry as a baseline, we determined changes in reported sexual behaviour after 6, 12 and 18 months of participation in the trial.Results
Of 291 HIV-seronegative MSM enrolled from July to October 1999, 260 (89%) completed 18 months of follow-up, 19 (7%) experienced seroconversion, and 12 (4%) did not complete follow-up. Unprotected receptive anal intercourse during the previous 6 months with partners whose HIV-1 serostatus was positive or unknown was reported by 21% of men at enrolment and by 27% at any point during 18 months of follow-up. No increase in this behaviour from baseline was reported by participants, including among men who were motivated to enrol because of expected protection from HIV-1 infection, men who believed they had received the vaccine, men who believed that the vaccine had greater than 50% efficacy, or men who believed that they had received the vaccine and that vaccine efficacy was greater than 50%.Interpretation
MSM can be successfully enrolled in HIV-1 vaccine efficacy trials without evident increases in those sexual behaviours most associated with HIV-1 risk.Development of preventive HIV-1 vaccines requires clinical trials that effectively recruit, enrol and retain high-risk subjects, including men who have sex with men (MSM). Since candidate vaccines may prove to have little or no efficacy, these trials must also strive to minimize harms associated with participation. A major concern has been that trial participants might believe vaccination affords some protection and therefore increase their sexual risk-taking.1,2 This concern derives in part from increases in unprotected anal intercourse observed during phase I and phase II vaccine trials. For example, self-reports of unprotected insertive anal intercourse during the previous 6 months increased among 44 gay men enrolled in San Francisco trials, from 9% at enrolment to 20% at the 12-month assessment; however, the HIV status of sexual partners was not assessed.1 The world''s first phase III trial to evaluate a candidate preventive HIV-1 vaccine was recently completed in North America and Europe.2 A consortium sponsored by the Canadian Network for Vaccines and Immunotherapeutics of Cancer and Chronic Viral Diseases (CANVAC) was formed to assess participation, retention and change in sexual risk behaviour at trial sites in this country. We report here the Canadian experience in this trial through 18 months of follow-up and assess trends in high-risk sexual behaviour reported by participants. 相似文献18.
Keshab Deuba Anna Mia Ekstr?m Rachana Shrestha George Ionita Laxmi Bhatta Deepak Kumar Karki 《PloS one》2013,8(3)
Background
Men who have sex with men (MSM) are marginalized, hidden, underserved and at high risk for HIV in Nepal. We examined the association between MSM sub-populations, psychosocial health problems and support, access to prevention and non-use of condoms.Methods
Between September-November of 2010, a cross-sectional survey on HIV-related risk behavior was performed across Nepal through snowball sampling facilitated by non-governmental organizations, recruiting 339 MSM, age 15 or older. The primary outcomes were: (a) non-use of condoms at least once in last three anal sex encounters with men and (b) non-use of condoms with women in the last encounter. The secondary outcome was participation in HIV prevention interventions in the past year.Results
Among the 339 MSM interviewed, 78% did not use condoms at their last anal sex with another man, 35% did not use condoms in their last sex with a woman, 70% had experienced violence in the last 12 months, 61% were experiencing depression and 47% had thought of committing suicide. After adjustment for age, religion, marital status, and MSM subpopulations (bisexual, ta, meti, gay), non-use of condoms at last anal sex with a man was significantly associated with non-participation in HIV interventions, experience of physical and sexual violence, depression, repeated suicidal thoughts, small social support network and being dissatisfied with social support. Depression was marginally associated with non-use of condoms with women. The findings suggest that among MSM who reported non-use of condoms at last anal sex, the ta subgroup and those lacking family acceptance were the least likely to have participated in any preventive interventions.Conclusions
MSM in Nepal have a prevalence of psychosocial health problems in turn associated with high risk behavior for HIV. Future HIV prevention efforts targeting MSM in Nepal should cover all MSM subpopulations and prioritize psychosocial health interventions. 相似文献19.
Background
Little is known about sexual risks and associated factors about female youths in semi-urban areas of Ethiopia. This study aimed to describe the nature and magnitude of risky sexual behaviors, and the socio-demographic and behavioral determinants among female youths in Tiss Abay, a semi-urban area on the outskirts of Bahir Dar City of the Amhara Region in northern Ethiopia.Methods
A cross-sectional census type study was conducted among female youths who were unmarried and aged 15–29 years in September 2011.Results
711 female youths participated in the study, with the mean age of initiation of sex of 78.6% being16.73±2.53 years. Only 52(9.3%) used condom during the first sex. Within the last 12 months, 509(71.6%) had sexual intercourse and 278(54.6%) had two or more sex partners, and 316(62.1%) did not use condom during their last sex. Sex under the influence of substances was reported by 350(68.8%), and a third of the recent sexes were against the will of participants. One or more risky sexual practices were reported by 503(70.3%) participants, including: multiple sexual partnerships, inconsistently using or not using condoms, sex under the influence of alcohol and/or sex immediately after watching pornography. Age group, current marital status, drinking homemade alcohol, chewing ‘khat’, watching pornography and using any form of stimulant substances were the predictors of risky sexual behavior. Watching pornography before sex and sex for transaction were the predicators of not using condom during most recent sex.Conclusions
Risky sexual behaviors were very common among the female youths in Tiss Abay. Initiation of context-based interventions, such as raising awareness about the risks, safer sex practices, condom promotion and integration of gender issues in the programs are recommended. 相似文献20.
Amaya G. Perez-Brumer Kelika A. Konda H. Javier Salvatierra Eddy R. Segura Eric R. Hall Silvia M. Montano Thomas J. Coates Jeff D. Klausner Carlos F. Caceres Jesse L. Clark 《PloS one》2013,8(4)