260 research outputs found
A sex-role-preference model for HIV transmission among men who have sex with men in China
Background: Men who have sex with men (MSM) are much more likely to be infected with HIV
than the general population. China has a sizable population of MSM, including gay, bisexual men,
money boys and some rural workers. So reducing HIV infection in this population is an important
component of the national HIV/AIDS prevention and control program.
Methods: We develop a mathematical model using a sex-role-preference framework to predict
HIV infection in the MSM population and to evaluate different intervention strategies.
Results: An analytic formula for the basic reproduction ratio R0 was obtained; this yields R0 =
3.9296 in the current situation, so HIV will spread very fast in the MSM population if no intervention
measure is implemented in a timely fashion. The persistence of HIV infection and the existence of
disease equilibrium (or equilibria) are also shown. We utilized our model to simulate possible
outcomes of antiretroviral therapy and vaccination for the MSM population. We compared the
effects of these intervention measures under different assumptions about MSM behaviour. We also
found that R0 is a decreasing function of the death rate of HIV-infected individuals, following a
power law at least asymptotically.
Conclusion: HIV will spread very fast in the MSM population unless intervention measures are
implemented urgently. Antiretroviral therapy can have substantial impact on the reduction of HIV
among the MSM population, even if disinhibition is considered. The effect of protected sexual
behaviour on controlling the epidemic in the MSM population largely depends on the sex-ratio
preference of different sub-populations
Two-stage Sampling on Additive Model for Quantitative Sensitive Question Survey and Its Application
Objective To explore scientiļ¬c sampling methods and corresponding formulas for quantitative sensitive question survey on two-stage random sampling. To provide scientiļ¬c data for the prevention and control of high risk AIDS population in Beijing. Methods Additive model for quantitative sensitive question survey, two-stage random sampling, properties of variance and mean were used. Results Formulas for the estiĀ¬mation of the population proportions and its variance on additive model for quantitative sensitive question survey were deduced. The survey methods and formulas were employed successfully in the survey of the age of the ļ¬rst time when MSM having sex with men and the result was 21.9747. Conclusion The methods and corresponding formulas for two-stage sampling on additive model for quantitative sensitive question survey are feasible. Key words: Sensitive questions; Additive model for randomized response technique; Two-stage sampling; MS
Association Between Stigma Towards HIV and MSM and Intimate Partner Violence Among Newly HIV-Diagnosed Chinese Men Who Have Sex With Men
Background: HIV- and MSM-related stigma are well documented as common for Chinese men who have sex with men (MSM) living with HIV, yet there is sparse literature on intimate partner violence (IPV) and its relationship with stigma in this vulnerable population. To evaluate the association between HIV-stigma and stigma related to homosexuality and IPV among newly HIV-diagnosed MSM in China. Methods: Data were collected in the baseline survey among newly HIV-diagnosed Chinese MSM in a randomized clinical trial via face-to-face interviews. Univariate logistic and multivariate logistic regression analyses were performed to assess the associations between IPV and HIV- and MSM-related stigma. Results: Of 367 newly HIV-diagnosed Chinese MSM, 23.7% experienced any IPV, including 16.6% physical, 7.4% psychological and 5.2% sexual IPV. Positive associations were found between HIV- and MSM-related stigma and IPV. Men with high HIV-related stigma (score ā„ 27) were 1.67 times as likely to experience any IPV as those with low stigma (adjusted odds ratio [AOR]: 1.67, 95% confidence interval [CI]: 1.02-2.76). Men with high MSM-related stigma (score ā„ 6) were 1.99 times as likely to experience any IPV as those with low stigma (AOR: 1.99, 95% CI: 1.18-3.36). Conclusions: HIV- and MSM-related stigmas was positively associated with IPV experiences among newly diagnosed MSM in China. The manner in which stigma may exacerbate IPV, and/or the influence of IPV on worsening stigma should be further evaluated. The high prevalence of IPV and stigma in this population suggests that interventions should be taken to reduce stigma and prevent this risky behavior among MSM
A new pattern-based method for identifying recent HIV-1 infections from the viral env sequence
New pattern-based method for identifying recent HIV-1 infections from the viral env sequence
The study investigates a pattern-based method for measuring intra-patient viral genetic diversity for determination of recent infections and estimation of population incidence. Pattern-based diversities of recent infections are significantly lower than that of chronic ones. With larger window periods varying from 200 to 350 days, a higher accuracy (90%95%) not affected by advanced disease nor antiretroviral therapy (ART) treatment could be obtained. The pattern-based genetic method is supplementary to existing serology-based assays, both suitable for use in low and high epidemic regions respectively. The envelope (env) gene of HIV/SIV is the most variable of viral genes
Association between Stigma and Intimate Partner Violence among Newly HIV-Diagnosed Chinese Men Who Have Sex with Men
Introduction: Men who have sex with men (MSM) are more likely to experience Intimate partner violence (IPV) during their lifetime than heterosexual couples. HIV-status and related HIV stigma may play an important role in IPV within intimate partnerships among MSM. HIV- and MSM-related stigmas are common among Chinese MSM, yet there is sparse literature on IPV and its relationship with stigma in this vulnerable population. We evaluate the prevalence of IPV and its relationship with HIV- and MSM-related stigma among newly diagnosed HIV-infected MSM in Beijing, China.
Methods: Data were collected in the baseline survey among newly HIV-diagnosed Chinese MSM in a randomized clinical trial via face-to-face interviews. Simple and multiple logistic regression analyses were performed to assess the associations between IPV and HIV- and MSM-related stigma.
Results: Of 367 newly HIV-diagnosed Chinese MSM, 23.7% experienced any IPV, including 16.6% physical, 7.4% psychological and 5.2% sexual IPV. Positive associations were found between HIV- and MSM-related stigma and IPV. Men with high HIV-related stigma (score ā„27) were 1.68 times as likely to experience any IPV as those with low stigma (adjusted odds ratio [AOR]: 1.68, 95% confidence interval [CI]: 1.03-2.76). Men with high MSM-related stigma (score ā„6) were 1.98 times as likely to experience any IPV as those with low stigma (AOR: 1.98, 95% CI: 1.19-3.31). Men with high HIV- and MSM-related stigma were 2.86 times as likely to experience any IPV as those with low stigma (AOR: 2.86, 95% CI: 1.44-5.69).
Conclusion: HIV- and MSM-related stigma was positively associated with IPV experiences among newly diagnosed MSM in China. The manner in which stigma may exacerbate IPV, and/or the influence of IPV on worsening stigma should be further evaluated. The high prevalence of IPV and stigma in this population suggests that interventions should be taken to reduce stigma and prevent this risky behavior among MSM
Mortality and Attrition Rates within the First Year of Antiretroviral Therapy Initiation among People Living with HIV in Guangxi, China: An Observational Cohort Study
Objective. To assess the mortality and attrition rates within the first year of antiretroviral therapy (ART) initiation among people living with human immunodeficiency virus (PLHIV) in rural Guangxi, China. Design. Observational cohort study. Setting. The core treatment indicators and data were collected with standard and essential procedures as per the Free ART Manual guidelines across all the rural health care centers of Guangxi. Participants. 58,115 PLHIV who were under ART were included in the study. Interventions. The data collected included sociodemographic characteristics that consist of age, sex, marital status, route of HIV transmission, CD4 cell count before ART, initial ART regimen, level of ART site, and year of ART initiation. Primary and Secondary Outcome Measures. Mortality and attrition rate following ART initiation. Results. The average mortality rate was 5.94 deaths, and 17.52 attritions per 100 person-years within the first year of ART initiation among PLHIV. The mortality rate was higher among intravenous drug users (Adjusted Hazard Ratio (AHR) 1.27, 95% Confidence Interval (CI) 1.14-1.43), prefecture as a level of ART site (AHR 1.14, 95% CI 1.02-1.28), and county as the level of ART site (AHR 2.12, 95% CI 1.90-2.37). Attrition was higher among intravenous drug users (AHR 1.87, 95% CI 1.75-2.00), the first-line ART containing AZT (AHR 1.09, 95% CI 1.03-1.16), and first-line ART containing LVP/r (AHR 1.34, 95% CI 1.23-1.46). Conclusion. The mortality and attrition rates were both at the highest level in the first year of post-ART; continued improvement in the quality of HIV treatment and care is needed
Qualitative Assessment of Barriers and Facilitators of Access to HIV Testing Among Men Who Have Sex with Men in China
Diagnosis of HIV is the entry point into the continuum of HIV care; a well-recognized necessary condition for the ultimate prevention of onward transmission. In China, HIV testing rates among men who have sex with men (MSM) are low compared to other high risk subgroups, yet experiences with HIV testing among MSM in China are not well understood. To address this gap and prepare for intervention development to promote HIV testing and rapid linkage to treatment, six focus groups (FGs) were conducted with MSM in Beijing (40 HIV-positive MSM participated in one of four FGs and 20 HIV-negative or status unknown MSM participated in one of two FGs). Major themes reported as challenges to HIV testing included stigma and discrimination related to HIV and homosexuality, limited HIV knowledge, inconvenient clinic times, not knowing where to get a free test, fear of positive diagnosis or nosocomial infection, perceived low service quality, and concerns/doubts about HIV services. Key facilitators included compensation, peer support, professionalism, comfortable testing locations, rapid testing, referral and support after diagnosis, heightened sense of risk through engagement in high-risk behaviors, sense of responsibility to protect self, family and partner support, and publicity via social media. Themes and recommendations were generally consistent across HIV-positive and negative/status unknown groups, although examples of enacted stigma were more prevalent in the HIV-positive groups. Findings from our study provide policy suggestions for how to bolster current HIV prevention intervention efforts to enhance ?test-and-treat? strategies for Chinese MSM.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140221/1/apc.2015.0083.pd
Effects of high CD4 cell counts on death and attrition among HIV patients receiving antiretroviral treatment: an observational cohort study
Current WHO guidelines recommend initiating ART regardless of CD4+ cell count. In response, we conducted an observational cohort study to assess the effects of pre-ART CD4+ cell count levels on death, attrition, and death or attrition in HIV treated patients. This large HIV treatment cohort study (n = 49,155) from 2010 to 2015 was conducted in Guangxi, China. We used a Cox regression model to analyze associations between pre-ART CD4+ cell counts and death, attrition, and death or attrition. The average mortality and ART attrition rates among all treated patients were 2.63 deaths and 5.32 attritions per 100 person-years, respectively. Compared to HIV patients with 500 CD4+ cells/mm 3 at ART initiation had a significantly lower mortality rate (Adjusted hazard ratio: 0.56, 95% CI: 0.40-0.79), but significantly higher ART attrition rate (AHR: 1.17, 95% CI: 1.03-1.33). Results from this study suggest that HIV patients with high CD4+ cell counts at the time of ART initiation may be at greater risk of treatment attrition. To further reduce ART attrition, it is imperative that patient education and healthcare provider training on ART adherence be enhanced and account for CD4 levels at ART initiation
- ā¦