Sexual risk behaviour of men who have sex with men: emerging patterns and new challenges

Risk reduction practices in men who have sex with men in Switzerland: serosorting, strategic positioning, and withdrawal before ejaculation

The aim of this study was to identify predictors of intentional use of the HIV risk reduction practices of serosorting, strategic positioning, and withdrawal before ejaculation during unprotected anal intercourse (UAI) with casual partners. A cross-sectional survey pertaining to the Swiss HIV behavioral surveillance system, using an anonymous self-administered questionnaire, was conducted in 2007 in a self-selected sample of men having sex with other men (MSM). Analysis was restricted to participants with UAI with casual partner(s) (N = 410). Logistic regression was used to estimate factors associated with intentional use of serosorting, strategic positioning, and withdrawal before ejaculation. In the previous 12 months, 71% of participants reported having UAI with a casual partner of different or unknown HIV-status. Of these, 47% reported practicing withdrawal, 38% serosorting, and 25% strategic positioning. In the 319 participants with known HIV-status, serosorting was associated with frequent Internet use to find partners (OR = 2.32), STI (OR = 2.07), and HIV testing in the past 12 months (OR = 1.81). Strategic positioning was associated with HIV-status (OR = 0.13) and having UAI with a partner of different or unknown HIV-status (OR = 3.57). Withdrawal was more frequently practiced by HIV-negative participants or participants reporting high numbers of sexual partners (OR = 2.48) and having UAI with a partner of unknown or different serostatus (OR = 2.08). Risk reduction practices are widely used by MSM, each practice having its own specificities. Further research is needed to determine the contextual factors surrounding harm reduction practices, particularly the strategic or opportunistic nature of their use.

Towards condom skills: a cross-sectional study of the association between condom proficiency, condom problems and STI risk amongst MSM

BACKGROUND

Condom use problems are common amongst Scotland's men who have sex with men (MSM). To date condom errors have been associated with the likelihood of sexually transmitted infections in heterosexual sexually transmitted infection (STI) clinic attendees but not in MSM and direct evidence of a link between condom problems and STI acquisition in MSM have been lacking. This study investigated the possibility of an independent association between condom proficiency, condom problems and STI acquisition in MSM in Scotland.

METHODS

An exploratory observational design employed cross-sectional surveys in both STI clinic and community settings. Respondents completed self-report measures of socio-demographic variables, scales of condom proficiency and condom problems and numbers of different partners with whom men have had unprotected anal intercourse (UAI partners) in the preceding year. Self-report data was corroborated with clinical STI diagnosis where possible. Analysis included chi-squared and Mann-Whitney tests and multiple logistic regression.

RESULTS

792 respondents provided data with an overall response rate of 70% (n = 459 clinic sample, n = 333 community sample). Number of UAI partners was the strongest predictor of self-reported STI acquisition over the previous 12 months (p < 0.001 in both clinic and community samples). Demographic characteristics were not associated with self-reported STI diagnosis. However, condom proficiency score was associated with self-reported STI acquisition (p < 0.05 in both samples). Condom problem score was also associated with self-reported STI diagnosis in the clinic (p = 0.001) but not the community sample. Condom problem score remained associated with self-reported STI diagnosis in the clinic sample after adjusting for number of UAI partners with logistic regression.

CONCLUSIONS

This exploratory study highlights the potential importance of targeted condom use skills interventions amongst MSM. It demands further research examining the utility of condom problem measures in wider populations, across prospective and experimental research designs, and a programme of research exploring their feasibility as a tool determining candidacy for brief interventions.

Comprehensive clinical care for men who have sex with men: an integrated approach

Men who have sex with men (MSM) have unique health-care needs, not only because of biological factors such as an increased susceptibility to infection with HIV and sexually transmitted infections associated with their sexual behaviour, but also because of internalisation of societal stigma related to homosexuality and gender non-conformity, resulting in depression, anxiety, substance use, and other adverse outcomes. Successful responses to the global HIV/AIDS epidemic will require the development of culturally sensitive clinical care programmes for MSM that address these health disparities and root causes of maladaptive behaviour (eg, societal homophobia). Health-care providers need to become familiar with local outreach agencies, hotlines, and media that can connect MSM with positive role models and social opportunities. Research is needed to understand how many MSM lead resilient and productive lives in the face of discrimination to develop assets-based interventions that build on community support. Optimum clinical care for sexual and gender minorities is a fundamental human right. MSM deserve to be treated with respect, and health-care providers need to interact with them in ways that promote disclosure of actionable health information.

Distinct Neisseria gonorrhoeae transmission networks among men who have sex with men in Amsterdam, The Netherlands

BACKGROUND

Molecular typing was used to elucidate Neisseria gonorrhoeae transmission networks among men who have sex with men (MSM) in Amsterdam, the Netherlands. We determined whether clusters of patients infected with specific N. gonorrhoeae genotypes were related to various epidemiological characteristics.

METHODS

MSM (age ≥18 years) visiting the sexually transmitted infections (STI) clinic between July 2008 and August 2009 were eligible. After STI screening, participants completed a behavioral questionnaire concerning the previous 6 months. N. gonorrhoeae cultures were genotyped using multiple-locus variable-number tandem repeat analysis typing.

RESULTS

We obtained 278 N. gonorrhoeae-positive isolates from 240 MSM. Five large clusters (≥10 isolates), a unique sixth cluster (n = 9), and 8 smaller clusters (5-9 isolates) were identified. Prevalence of human immunodeficiency virus differed between clusters I and VI (P = .003), ranging from 27.8% to 100%. Receptive unprotected anal intercourse was frequently reported by MSM (51.8%) but did not differ significantly among clusters. Significant differences were identified concerning the participant's history of syphilis (P = .030), having met partners at a popular sex venue in Amsterdam (P = .048), and meeting partners outside Amsterdam (P = .036).

CONCLUSIONS

Distinct N. gonorrhoeae transmission networks were present in a mixed high-risk MSM population; concordance between clusters and epidemiological characteristics was present but not marked.

HIV risk among men who have sex with men who have experienced childhood sexual abuse: systematic review and meta-analysis

Previous research has indicated a high prevalence of childhood sexual abuse (CSA) among men who have sex with men (MSM) in the United States, and has suggested that CSA history is a risk factor for HIV infection in MSM. We conducted a systematic review to identify, synthesize, meta-analyze, and critique the current state of relevant literature. Systematic review methodology was utilized to identify 12 studies that compared MSM with a history of CSA to MSM without a history of CSA on HIV risk indicators including HIV serostatus, sexually transmitted infections (STIs), sexual behaviors, and illicit drug use. Overall, 27.3% (n = 4,263) of the MSM in all included studies (n = 15,622) reported a CSA history. Across the studies that used probabilistic sampling (n = 8,240), the estimated prevalence of CSA was 21.8% (n = 1,800). Meta-analysis indicated that MSM with CSA history were more likely to be HIV positive [odds ratio (OR) = 1.54; 95% confidence interval (CI) = 1.22-1.95)] and to engage in recent unprotected anal intercourse (OR = 1.85, 95% CI = 1.36-2.51). Studies also indicated that MSM with a history of CSA were more likely to report frequent casual male partners, substance use, and sex while under the influence of alcohol or other drugs. Trends across studies indicated a need for interventions to assess CSA history and address effects of CSA on sexual risk behavior of MSM. Inconsistencies across studies indicated a need to reach consensus among researchers and providers in defining CSA.

Comparison of sexual behavior and HIV risk between two HIV-1 serodiscordant couple cohorts: the CHAVI 002 study

BACKGROUND

The CHAVI002 study was designed to characterize immune responses, particularly HIV-specific T-cell responses, amongst 2 cohorts of HIV-exposed seronegative (HESN) individuals. The absence of a clear definition of HESNs has impaired comparison of research within and between such cohorts. This report describes two distinct HESN cohorts and attempts to quantify HIV exposure using a 'HIV risk index' (RI) model.

METHODS

HIV serodiscordant couples (UK; 24, Uganda; 72) and HIV unexposed seronegative (HUSN) controls (UK; 14, Uganda; 26 couples, 3 individuals) completed sexual behavior questionnaires every 3 months over a 9 month period. The two cohorts were heterogeneous, with most HESNs in the UK men who have sex with men (MSM), while all HESNs in Uganda were in heterosexual relationships. Concordance of responses between partners was determined. Each participant's sexual behavior score (SBS) was estimated based on the number and type of unprotected sex acts carried out in defined time periods. Independent HIV acquisition risk factors (partner plasma viral load, STIs, male circumcision, pregnancy) were integrated with the SBS, generating a RI for each HESN.

RESULTS

96 HIV serodiscordant couples completed 929 SBQs. SBSs remained relatively stable amongst the UK cohort, whilst decreasing from Visit 1 to 2 in the Ugandan cohort. Compared to the Ugandan cohort, SBSs and RIs in the UK cohort were lower at visit 1, and generally higher at later visits. Differences between the cohorts, with lower rates of ART use in Uganda and higher risk per-act sex in the UK, had major impacts on the SBSs and RIs of each cohort. There was one HIV transmission event in the UK cohort.

CONCLUSIONS

Employment of a risk quantification model facilitated quantification and comparison of HIV acquisition risk across two disparate HIV serodiscordant couple cohorts.

The impact of HIV seroadaptive behaviors on sexually transmissible infections in HIV-negative homosexual men in Sydney, Australia

BACKGROUND

Human immunodeficiency virus (HIV) seroadaptive behaviors, such as serosorting and strategic positioning, are being increasingly practised by homosexual men; however, their impact on sexually transmissible infections is unclear.

METHODS

Participants were 1427 initially HIV-negative men enrolled from 2001 to 2004 and followed to June 2007. Participants were tested annually for anal and urethral gonorrhoea and chlamydia, herpes simplex virus, and syphilis. In addition, they reported diagnoses of these conditions, and of genital and anal warts between annual visits, and sexual risk behaviors.

RESULTS

Compared with men who reported no unprotected anal intercourse (UAI), serosorting was associated with an increased risk of urethral (incidence: 6.06 vs. 3.56 per 100 person-years (PY), hazard ratio (HR) = 1.97, 95% confidence interval [CI]: 1.43-2.72) and anal (incidence 3.95 vs. 2.80 per 100 PY, HR = 1.62, 95% CI: 1.11-2.36) chlamydia. Compared with men who reported UAI with HIV nonconcordant partners, men who practised serosorting had significantly lower risk of incident syphilis (incidence 0.18 vs. 1.00 per 100 PY, HR = 0.21, 95% CI: 0.05-0.81) and urethral gonorrhoea (incidence 2.15 vs. 5.52 per 100 PY, HR = 0.61, 95% CI: 0.39-0.96). Compared with men who reported no UAI, strategic positioning was associated with an increased risk of urethral gonorrhoea (incidence 4.11 vs. 2.10 per 100 PY, HR = 1.72, 95% CI: 1.05-2.83) and chlamydia (incidence 8.71 vs. 3.56 per 100 PY, HR = 2.22, 95% CI: 1.55-3.18). Compared with men who reported receptive UAI, the incidence of anal gonorrhoea (incidence 1.48 vs. 3.83 per 100 PY, HR = 0.38, 0.20-0.74) and chlamydia (incidence 3.10 vs. 6.30 per 100 PY, HR = 0.44, 95% CI: 0.27-0.69) was significantly lower in those who practised strategic positioning.

CONCLUSION

For men who reported seroadaptive behaviors, rates of some bacterial sexually transmissible infections were higher than in men who reported no UAI. However, rates were lower than for men who reported higher HIV risk behaviors.

The critical role of intimacy in the sexual risk behaviors of gay and bisexual men

Research indicates that high numbers of gay and bisexual men report infrequent or inconsistent condom use, placing them at risk for HIV and other STDs. The present study examined positive and negative condom-related attitudes along three dimensions-risk reduction, pleasure reduction, and intimacy interference-and examined their relative predictive power in determining condom use among a sample of sexually risky gay and bisexual men in New York City. In a multivariate model, both risk reduction and intimacy interference attitudes emerged as significant predictors of unprotected sex; however, the variance accounted for by a model including intimacy interference was almost three times that accounted for by a model including risk reduction alone. These data suggest a pivotal role for intimacy in shaping condom attitudes and behavior among gay and bisexual men. HIV prevention interventions should consider incorporating intimacy as a motivating factor for sexual behavior and a potential barrier to condom use.

Middle-aged and older men who have sex with men exhibit multiple trajectories with respect to the number of sexual partners

This study aimed to examine trajectories with respect to the number of sexual partners among older men who have sex with men and to determine characteristics associated with trajectory groups. Nagin's group-based modeling was used to identify trajectories for 237 men from the Pitt Men's Study with respect to the number of male intercourse partners from age 50.0 to 59.5. Three distinct trajectory groups were identified. Most men (69.2%) had a median of two sexual partners in the past 6 months across the age range of the study. A smaller group (19.4%) had low or no sex partners. The smallest group (11.4%) had 30 or more sexual partners in the past 6 months at age 50. The groups were statistically different with respect to race, HIV status, drug use (marijuana, poppers, crack cocaine, and Viagra), the number of unprotected anal sex partners, and personal attitudes towards sex.

Transmen: the HIV risk of gay identity

Many female-to-male transgender individuals, or transmen, are situated within the gay community, one of the highest risk communities for HIV, yet there has been little research regarding the experience of risk for these transmen. Seventeen transmen were interviewed regarding their sexuality and HIV risk behavior. Fourteen of the 17 reported having non-trans gay men as sexual partners. Risk behaviors included not using condoms with multiple partners who were HIV-positive, or of unknown HIV status. Aspects of risk included the unfamiliarity of the gay community and the lack of safe sex negotiating skills. The dynamics of acceptance and rejection between transmen and non-trans gay men impacted risk by compromising safety. Incorrect assumptions regarding transmen, non-trans gay men, and risk included beliefs that neither person could be at risk. Other aspects included the impact of testosterone on sexual behavior, the changed bodies of transmen, and sex work.

Characteristics of HIV epidemics driven by men who have sex with men and people who inject drugs

PURPOSE OF REVIEW

To highlight the latest developments in mathematical transmission modelling of HIV epidemics among men who have sex with men (MSM) and people who inject drugs (PWID).

RECENT FINDINGS

Mathematical approaches have been applied to a wide range of topics in recent HIV research. Epidemiological models have evaluated past and forecasted future trends in prevalence and incidence, evaluated innovative behaviour modification strategies and public health programmes aimed at minimizing risk, and explored the potential impact of various biomedical interventions. MSM have developed new risk reduction strategies which models have deemed to be effective at a population level only in certain settings, such as when there are high rates of HIV testing. Modelling has also indicated that persistent circulation of drug-resistant HIV strains is likely to become an inevitable public health issue in the near future in resource-rich settings among MSM. Models have also recently been used to demonstrate that needle and syringe programmes for harm reduction among PWID are effective and cost-effective.

SUMMARY

Mathematical modelling is particularly amenable to single population groups of concentrated HIV epidemics, such as among MSM and PWID. Models have been utilized to evaluate innovative areas in clinical, biomedical and public health research that cannot be conducted in other population groups. Future directions are likely to include evaluation of specific public health programmes and providing understanding of the importance of specific treatment regimens and incidence and interaction of comorbid conditions associated with HIV.

Sexual contexts and the process of risk reduction

Understanding the dynamics of sexual risks for HIV among men who have sex with men has been one of the ongoing challenges of HIV prevention. While the majority of HIV-prevention interventions target individual behaviour and decision making, multiple studies point to the importance of social context in shaping risk behaviour. Analysis of qualitative data from a study of men who have sex with men, drug use and sex found that sexual encounters were made up multiple contextual and interpersonal elements, which interacted to shape sexual practices and risk reduction strategies. Semi-structured interviews were conducted with 60 racially diverse men who have sex with men in NYC, recruited from multiple venues. The majority of respondents were gay-identified and half were 40 or older. Respondents described risk assessment and risk-reduction processes that develop throughout a sexual encounter, embedded in ongoing negotiations of sexual practices. Strategies of risk assessment and reduction draw on probability-based approaches to HIV prevention, presenting a challenge to health education.

Sexual agreement classifications for gay and bisexual men and implications for harm reduction HIV prevention

HIV prevention educators frequently encourage gay and bisexual men (GBM) to negotiate condom use prior to sexual engagement. Identifying groups of GBM based on their presexual agreements can aid efforts to tailor interventions. Using cross-sectional data from 1,188 GBM who reported having sex with a nonprimary sex partner in the 90 days prior to the survey, the authors identified presexual agreement patterns. For both HIV-positive and HIV-negative GBM, two groups existed: men agreeing to no anal sex and men agreeing to anal sex with condoms. Among HIV-negative participants, there was a group agreeing to anal sex without specifying condom use. Among HIV-positive participants, there was a group agreeing to anal sex without condoms; this was the largest group of HIV-positive participants. Despite a presexual agreement to use condoms, substance use during sex increased the risk of unprotected anal sex. Suggestions for applying harm reduction to HIV prevention based on agreement classifications are discussed.

Predictors of retention in an online follow-up study of men who have sex with men

BACKGROUND

In the past 10 years, the Internet has emerged as a venue for men who have sex with men (MSM) to meet sex partners. Because online sex seeking has increased among MSM, Internet-based human immunodeficiency virus (HIV) prevention interventions are of interest. However, few online studies to date have demonstrated an ability to retain study participants, specifically MSM of color, in longitudinal online studies.

OBJECTIVE

The current analysis examines data from a 3-month online prospective study of MSM to determine the association of race and incentive level with two retention outcomes: (1) agreeing to participate in a follow-up survey and providing an email address and (2) linking into the follow-up survey at the follow-up time point.

METHODS

Internet-using MSM were recruited through banner advertisements on MySpace.com. White, black, and Hispanic participants from 18 to 35 years of age were randomized to an offer of enrollment in an online follow-up survey at four levels of incentive (US $0, US $5, US $10, and US $20). Multivariable logistic regression models were used to estimate the odds of the two outcome measures of interest controlling for additional independent factors of interest.

RESULTS

Of eligible participants, 92% (2405/2607) agreed to participate in the follow-up survey and provided an email address. Hispanic men had decreased odds (adjusted odds ratio [OR] = 0.66, 95% confidence interval [CI] 0.47-0.92) of agreeing to participate in the follow-up survey compared with white men. Men reporting unprotected anal intercourse with a male sex partner in the past 12 months had increased odds of agreeing to participate in the follow-up survey (adjusted OR = 1.42, 95% CI 1.05-1.93). Of the participants who provided an email address, 22% (539/2405) linked into the follow-up survey at the 3-month follow-up time point. The odds of linking into the follow-up survey for black men were approximately half the odds for white men (adjusted OR = 0.47, 95% CI 0.35-0.63). Participants who were offered an incentive had increased odds of linking into the follow-up survey (adjusted OR = 1.29, 95% CI 1.02-1.62). Email addresses provided by participants that were used for online financial management and email accounts that were checked daily were associated with increased odds of linking into the follow-up survey (adjusted OR = 1.97, 95% CI 1.54-2.52; adjusted OR = 1.51, 95% CI 1.22-1.87, respectively).

CONCLUSIONS

This analysis identified factors that predicted retention in an online, prospective study of MSM. Hispanic and black study participants were less likely to be retained in the study compared with white study participants. Because these men bear the greatest burden of HIV incidence among MSM in the United States, it is critical that new research methods be developed to increase retention of these groups in online research studies.

Trends in unsafe sex and influence of viral load among patients followed since primary HIV infection, 2000-2009

BACKGROUND

In the current context of increasing unsafe sex, HIV incidence may have evolved, depending on HIV prevalence in sexual networks and, among HIV-infected persons who practice unsafe sex, on their infectivity and partners' HIV serostatus. We examined calendar trends in sexual behaviours at risk of HIV-1 transmission (SBR) among 967 adults followed since primary HIV infection (ANRS PRIMO cohort) and relationship with current treatments and viral load.

METHODS

Patients completed since 2000 self-administered questionnaires on sexual practices every 6 months. SBR with HIV-negative/unknown partners were analyzed among 155 heterosexual women, 142 heterosexual men and 670 MSM by using logistic generalized estimating equation models (6656 visits).

RESULTS

During 2000-2009, the frequency of SBR did not increase significantly among women with steady partners; risk factors were a low education level and alcohol/smoking use. Among heterosexual men with steady partners, the frequency of SBR doubled since 2006; during this period, the only associated factor was combined antiretroviral treatment for at least 6 months or viral load less than 400 copies/ml. Among MSM, SBR increased gradually over time; SBR with steady partners was associated with a low education level and alcohol use. SBR was more frequent among MSM with casual partners; no association with viral load was found.

CONCLUSION

In France, recent trends and risk factors in unprotected sex with HIV-negative/unknown partners differ according to sex/sexual preference. The recent increase in SBR among heterosexual men with low viral load may be related to increasing awareness of the 'treatment-as-prevention' concept. The lack of association between SBR and viral load among MSM supports use of treatment-as-prevention as part of diversified prevention strategies.

HIV-related sexual risk behaviour between 1996 and 2008, according to age, among men who have sex with men (Scotland)

OBJECTIVE

To examine changes in the proportions of those reporting 2+ unprotected anal intercourse (UAI) partners in the previous 12 months among men who have sex with men (MSM) in Scotland between 1996 and 2008. Differences according to age group were also examined.

METHODS

Logistic regression was used with data from eight cross-sectional anonymous, self-report surveys in commercial gay venues in Glasgow and Edinburgh (N=10,223). Data were stratified according to survey and age group (<25 years vs ≥25 years).

RESULTS

The percentage of 2+ UAI partners reported in the previous 12 months increased significantly between 2000 and 2002, adjusted for age group. When the surveys were divided into two time periods (1996-2000 and 2002-2008), no significant differences were found within each time period in the percentage of 2+ UAI partners reported (adjusted for age group). However, a significant increase was found when the aggregated figures for 2002-2008 were compared with those for 1996-2000. At the aggregate level, those aged <25 years were significantly more likely than those aged ≥25 years to report 2+ UAI partners in the previous 12 months (adjusted for survey).

CONCLUSIONS

HIV-related sexual risk behaviour did not change significantly between 2002 and 2008 among MSM in Scotland, after the increases noted between 2000 and 2002. A significant minority of MSM continue to engage in relatively high levels of sexual risk, and younger generations appear to be at particular risk. This represents a public health concern and highlights the need for targeted age-specific interventions.

Reinfections during the Florida syphilis epidemic, 2000-2008

BACKGROUND

The last 3 syphilis epidemics in the United States peaked after 5 to 6 years, but rates have now increased for 8 years. We questioned whether persons with multiple syphilis diagnoses (repeaters) are fueling the epidemic.

METHODS

The Florida Department of Health database of all syphilis cases reported between 2000 and 2008 was used to examine demographics and disease presentation of repeaters and nonrepeaters using bivariate and multivariate analyses.

RESULTS

Of 26,070 persons diagnosed with syphilis, 643 (2.5%) were repeaters (range, 2-5 diagnoses): 82 women, 444 men who have sex with men (MSM), and 117 men identified as either heterosexual (n = 43) or unknown sexual orientation (n = 74). The mean time between first and second diagnosis was approximately 3 years. Median titer increase among those with a second diagnosis of early latent was 32-fold. In multivariate analysis, compared with nonrepeaters, repeaters were more likely to be MSM (odds ratio [OR], 5.3), human immunodeficiency virus (HIV)-infected (OR, 2.0), white (OR, 1.5), ages 35 to 39 (OR, 1.8), and to live in Miami-Dade or Broward Counties (OR, 1.7). Overall, the stage at diagnosis was similar for repeaters, whether it was their initial or subsequent diagnosis. However, HIV-infected MSM were more likely to be diagnosed with early latent at second diagnosis compared with initial diagnosis (P ≤ 0.01).

CONCLUSIONS

Most syphilis diagnosed in the current Florida epidemic is among persons infected for the first time. Repeaters are mainly MSM who present with symptoms or large increases in titers. HIV-infected MSM may have higher rates of early asymptomatic disease because of more frequent screening. These are likely to be true new infections.

Sexually transmissible infections in aging HIV populations

There is limited published research on sexually transmissible infections (STI) among aging HIV populations. The available literature on sexual behaviour and STI among older people with HIV is reviewed here and contrasted with data from older individuals in the general population and from older populations at high risk of HIV. A sizeable minority of older people with HIV continue to engage in higher risk sexual behaviour and thus remain at high risk of STI. There is no clear evidence of a consistent effect of older age on STI rates, clinical presentation or clinical course among HIV-infected populations, although gay men with HIV aged in their 40s or older seem to be at higher risk than younger men of acquiring several STI, including syphilis and lymphogranuloma venereum. STI risks in older people living with HIV need to be regularly assessed. Higher risk sexual behaviour and disproportionately higher rates of STI indicate that regardless of age, a thorough STI assessment should be regularly undertaken for all HIV-positive gay men as part of their routine HIV care.

Secondary prevention of HIV in the United States: past, current, and future perspectives

To provide a synopsis of past, current, and potential next-generation approaches to prevention for positives (PfP) interventions in the United States. For a variety of reasons, PfP interventions, with the goals of limiting HIV transmission from people living with HIV/AIDS (PLWHA) to others and protecting the health of PLWHA, did not appear with any frequency in the United States until about 2000. Even today, the number and breadth of evidence-based PfP interventions is very limited. Nevertheless, meta-analytic evidence demonstrates that such interventions can be effective, perhaps even more so than interventions targeting HIV-uninfected individuals. We review early and more recent PfP interventions and suggest that next-generation PfP interventions must involve behavioral and biologic components and target any element that affects HIV risk behavior and/or infectivity. Next-generation PfP interventions should include increased HIV testing to identify additional PLWHA, components to initiate and maintain HIV care, to initiate antiretroviral therapy and promote adherence, and to reduce sexual and injection drug use risk behavior, as well as ancillary treatments and referrals to services. Comprehensive next-generation PfP interventions, including all of these elements and effective linkages among them, are discussed.

Postexposure prophylaxis, preexposure prophylaxis or universal test and treat: the strategic use of antiretroviral drugs to prevent HIV acquisition and transmission

This review considers the use of antiretroviral drugs specifically to prevent HIV transmission. Antiretroviral therapy (ART) can be implemented for the protection of uninfected individuals both before (preexposure prophylaxis) and after (postexposure prophylaxis) exposure to HIV infection. Preexposure prophylaxis may be used coitally dependently when individuals are intermittently exposed or by continuous daily dosing for those constantly exposed; postexposure prophylaxis is used in 28-day courses. Alternatively, ART can be used strategically to reduce the viral load and consequent infectiousness of an HIV-infected individual, thereby limiting the risk of onward viral transmission. A policy of universal HIV testing to enhance the identification of all HIV-positive individuals followed by immediate treatment of all HIV-positive individuals, irrespective of their CD4 cell counts (universal test and treat), has been postulated as a potential tool capable of reducing HIV incidence at a population level. This concept represents a paradigm shift in the use of ART, targeting infectious individuals for prevention rather than protecting uninfected exposed populations. This strategy could have the advantage of preventing transmission and reducing HIV incidence at a population level, as well as delivering universal access to therapy for all people living with HIV and AIDS, potentially eliminating mother-to-child HIV transmission and limiting concomitant diseases such as tuberculosis. This review critically examines the scientific basis of ART for HIV prevention, summarizing the risks and opportunities of the potential expansion of ART for prevention. Specifically, we consider the evidences for and against targeting HIV-uninfected individuals compared with enhanced HIV testing and treatment of HIV-infected individuals in terms of impact on viral transmission.

An overview of the relative risks of different sexual behaviours on HIV transmission

PURPOSE OF REVIEW

Sexual intercourse represents the majority of HIV transmission and is preventable. Overall, the risk of HIV transmission following a single sexual exposure is low especially in comparison with other sexually transmitted infections (STIs), with estimates of the average probability of male-to-female HIV transmission only 0.0005-0.0026 per coital act. The risk of acquiring HIV from a single contact varies enormously and is dependant upon the infectiousness of the HIV-positive individual and the susceptibility to HIV of their sexual partner.

RECENT FINDINGS

Of concern, unprotected sex among men who have sex with men (MSM) has increased in recent years and HIV incidence in both MSM and heterosexuals remains a considerable public health concern. Sexual practices and health optimism about HIV have changed, which have significantly impacted HIV risk behaviour.

SUMMARY

In this review article we summarize the current evidence regarding the observed relative risks of HIV transmission for each different types of sex act, relationship type and the strategies that have been tested to interrupt transmission.

Sexual risk behaviour for transmission of HIV in men who have sex with men: recent findings and potential interventions

PURPOSE OF REVIEW

Men who have sex with men (MSM) remain one of the groups most at risk of HIV, particularly in countries with concentrated epidemics. Here, we review findings from behavioural research with MSM and discuss the potential of behavioural interventions.

RECENT FINDINGS

Increasing sexual risk behaviour and HIV transmission among MSM is apparent. Although risk reduction strategies, including serosorting and strategic positioning, are being widely reported, these appear to offer limited protection to HIV-negative MSM. There are emerging HIV epidemics among MSM in low-income and middle-income countries, with reported high levels of HIV and sexual risk behaviour. Studies of African MSM report higher HIV prevalence than that in the adult male general population. Evidence of effective behavioural interventions is growing. However, further trials, incorporating biological endpoints, are required.

SUMMARY

Reducing HIV transmission among MSM remains a significant challenge. Risk reduction strategies, other than condom use, could reduce the risk, but their efficacy is questionable, particularly when knowledge of HIV status may be inaccurate. Behaviour change alone is unlikely to produce the sustained reductions in HIV transmission necessary to change the course of the epidemic. 'Combination prevention', which incorporates biomedical, behavioural, social and structural interventions, should be explored further.