Unintentional HIV exposures from young men who have sex with men who disclose being HIV-negative

"Losing the Phobia:" Understanding How HIV Pre-exposure Prophylaxis Facilitates Bridging the Serodivide Among Men Who Have Sex With Men

The use of HIV serostatus information has played a pivotal role in partner selection norms. A phenomenon known as serosorting is the practice of selecting a partner based on a perception that they are of the same HIV status in order to avoid transmission from one partner to the other. An understudied aspect of serosorting is that it has a divisive effect-one accepts or rejects a potential partner based on a singular characteristic, the partner's HIV status, and thus excludes all others. This division has been formally referred to as the HIV serodivide. In this study, we explored partner selection strategies among a group of HIV-negative, young men who have sex with men (n = 29) enrolled in a PrEP demonstration project in Northern California. We found that trends in serosorting were in fact shifting, and that a new and opposite phenomenon was emerging, something we labeled "seromixing" and that PrEP use played a part in why norms were changing. We present three orientations in this regard: (1) maintaining the phobia: in which men justified the continued vigilance and exclusion of people living with HIV as viable sex or romantic partners, (2) loosening/relaxation of phobia: among men who were reflecting on their stance on serosorting and its implications for future sexual and/or romantic partnerships, and (3) losing the phobia: among men letting go of serosorting practices and reducing sentiments of HIV-related stigma. The majority of participants spoke of changing or changed attitudes about intentionally accepting rather than rejecting a person living with HIV as a sex partner. For those who maintained strict serosorting practices, their understandings of HIV risk were not erased as a result of PrEP use. These overarching themes help explain how PrEP use is contributing to a closing of the HIV serodivide.

The Cost-Effectiveness of Human Immunodeficiency Virus Testing and Treatment Engagement Initiatives in British Columbia, Canada: 2011-2013

Background

Recognition of the secondary preventive benefits of antiretroviral therapy (ART) has mobilized global efforts to "seek, test, treat, and retain" people living with human immunodeficiency virus [HIV]/AIDS (PLHIV) in HIV care. We aimed to determine the cost-effectiveness of a set of HIV testing and treatment engagement interventions initiated in British Columbia, Canada, in 2011-2013.

Methods

Using a previously validated dynamic HIV transmission model, linked individual-level health administrative data for PLHIV, and aggregate-level HIV testing data, we estimated the cost-effectiveness of primary care testing (hospital, emergency department [ED], outpatient), ART initiation, and ART retention initiatives vs a counterfactual scenario that approximated the status quo. HIV incidence, mortality, costs (in 2015$CDN), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios were estimated. Analyses were executed over 5- to 25-year time horizons from a government-payer perspective.

Results

ED testing was the best value at $30216 per QALY gained and had the greatest impact on incidence and mortality among PLHIV, while ART initiation provided the greatest QALY gains. The ART retention initiative was not cost-effective. Delivered in combination at the observed scale and sustained throughout the study period, we estimated a 12.8% reduction in cumulative HIV incidence and a 4.7% reduction in deaths among PLHIV at $55258 per QALY gained. Results were most sensitive to uncertainty in the number of undiagnosed PLHIV.

Conclusions

HIV testing and ART initiation interventions were cost-effective, while the ART retention intervention was not. Developing strategies to reengage PLHIV lost to care is a priority moving forward.

HIV Serosorting, Status Disclosure, and Strategic Positioning Among Highly Sexually Active Gay and Bisexual Men

Researchers have identified harm reduction strategies that gay, bisexual, and other men who have sex with men (GBMSM) use to reduce HIV transmission--including serosorting, status disclosure, and strategic positioning. We report on patterns of these behaviors among 376 highly sexually active (i.e., 9+partners, <90 days) GBMSM: mean age of 37, 49.5% men of color, 87.8% gay identified, 57.5% college educated. We found evidence that many men engaged in serosorting, status disclosure, and strategic positioning; however, rates varied based on the participant's HIV status. HIV-positive and HIV-negative men both engaged in sex with men of similar status more often than they engaged in sex with men known to be a different HIV status (i.e., serosorting). However, HIV-negative men disclosed their HIV-status with about half of their partners, whereas HIV-positive participants disclosed with only about one-third. With regard to strategic positioning, HIV-positive participants were the receptive partner about half the time with their HIV-negative partners and with their HIV-positive partners. In contrast, strategic positioning was very common among HIV-negative participants-they rarely bottomed with HIV-positive partners, bottomed about one-third of the time with status-unknown partners, and 42% of the time (on average) with HIV-negative partners. Highly sexually active GBMSM are a critical population in which to both investigate HIV prevention strategies as well as develop effective intervention programs. Providers and clinicians might be well served to include a wide range of behavioral harm reduction strategies in addition to condom use and biomedical approaches to reduce onward HIV transmission.

Racial differences in the accuracy of perceived partner HIV status among men who have sex with men (MSM) in Atlanta, Georgia

We compared perceptions of partner HIV status to HIV test results in a cross-sectional study of sexual networks of men who have sex with men (MSM) in Atlanta. We then examined differences between black and white MSM in the predictive value of perceived partner status. We recruited men ("seeds") using time-space venue sampling. These seeds then referred up to three partners, who could also refer partners. All participants reported sexual behavior and HIV status for recent partners and received HIV tests. For partners who enrolled, we compared laboratory diagnoses to their partner's perception of their status. Black MSM who perceived themselves to be HIV negative were more likely than perceived-negative white MSM to have a positive partner among those they perceived to be HIV negative or whose status was unknown to them (OR=6.6). Furthermore, although frequency of unprotected anal intercourse (UAI) was similar by race, black men were more likely to have had UAI with an unknown-positive partner (OR=9.3).

Attitude and behavior changes among gay and bisexual men after use of rapid home HIV tests to screen sexual partners

HIV testing can now be self-administered outside clinical settings through the purchase of home testing (HT) kits. Individuals also can use the kits to perform a test on a potential sexual partner prior to intercourse. We provided a 3-month supply of HT kits to men who reported multiple male partners and little or no condom use for anal intercourse. Participants used the test kits with partners in over 100 occasions. At the end of the study, approximately half of the participants described shifts in their attitudes and/or behaviors related to sexual risk. Reported changes included increased awareness of risk, increased discussion of STI/HIV safety measures, changes in partner choice and heightened consciousness of partner thinking. Easy access to HT kits may be a risk-reduction strategy for men with a high risk profile because their regular use could have an impact beyond the specific sexual encounter.

HIV-negative gay men's accounts of using context-dependent sero-adaptive strategies

We enrolled 166 gay and bisexual men who tested HIV-negative at a community sexual health clinic in Vancouver, British Columbia, into a year-long mixed-methods study. A subsample of participants who reported recent condomless anal sex (n = 33) were purposively recruited into an embedded qualitative study and completed two in-depth qualitative interviews. Analysis of baseline interviews elicited three narratives relevant to men's use of context- or relationally-dependent HIV-risk management strategies: (1) seroadaptive behaviours such as partner testing and negotiated safety agreements used with primary sexual partners, (2) serosorting and seroguessing when having sex with new partners and first-time hookups and (3) seroadaptive behaviours, including one or more of seropositioning/strategic positioning, condom serosorting and viral load sorting, used by participants who knowingly had sex with a serodiscordant partner. Within men's talk about sex, we found complex and frequently biomedically-informed rationale for seroadaptation in men's decisions to have what they understood to be various forms of safe or protected condomless anal sex. Our findings support the need for gay men's research and health promotion to meaningfully account for the multiple rationalities and seroadaptive strategies used for having condomless sex in order to be relevant to gay men's everyday sexual decision-making.

Self-efficacy among young men who have sex with men: an exploratory analysis of HIV/AIDS risk behaviors across partner types

HIV infection continues to rise among young men who have sex with men (YMSM). We explored whether unprotected receptive anal intercourse (URAI) occasions and partners, respectively, were associated with YMSM's (N = 194; ages 18-24) self-efficacy for safe sex with regular and casual partners. We created four self-efficacy typologies: high self-efficacy with both partner types [HRHC; N = 73(41.7 %)], high self-efficacy with regular partners but low with casual partners [HRLC; N = 24(13.7 %)], low self-efficacy with regular partners but high with casual partners [LRHC; N = 21(12.0 %)], and low with both partner types [LRLC; N = 57(32.6 %)]. YMSM in the LRHC category reported fewer URAI occasions, whereas those in the HRLC group reported more URAI partner and occasions, respectively. YMSM having serodiscordant partners were more likely to report more URAI partners, and be represented in the LRLC category. These findings underscore the importance of addressing differential self-efficacy across partner types, and highlight an urgent need to enhance YMSM's self-efficacy with casual partners.

Mutual HIV disclosure among HIV-negative men who have sex with men in Beijing, China, 2010

HIV is rising rapidly among Chinese men who have sex with men (MSM). Discussion of HIV status between sexual partners is potentially a key prevention behavior. It is unclear if HIV-negative Chinese MSM talk about HIV and disclose their HIV status with sexual partners. Understanding the correlates of disclosure among this population could provide insight into developing disclosure-based interventions. We conducted a respondent driven sampling based study of 500 MSM in Beijing. A total of 332 men had a previous HIV-negative test result and thus considered themselves to be HIV-negative and were included in our analysis of disclosure. Equal numbers of these men reported talking about HIV and disclosing their HIV status to at least one sexual partner. MSM who disclosed were more likely to be living with a main partner. No other demographic characteristics were associated with disclosure in bivariate analysis. We also used data on up to three sexual partners per participant to examine disclosure on the partnership level. Main partnerships, meeting partners at bars/clubs, sometimes using alcohol before sex in a partnership, and usually having sex at home compared to other venues were associated with disclosure. Using generalized estimating equation analysis to characterize individuals from their partnership data, we found only having at least one main partnership and knowing people who were infected with HIV to be associated with a participant being a discloser. Interventions that wish to harness discussion of HIV and HIV status among Chinese MSM will need to focus on moving these discussions towards having them with casual partners.

Men having sex with men serosorting with casual partners: who, how much, and what risk factors in Switzerland, 2007-2009

Background

Serosorting is practiced by men who have sex with men (MSM) to reduce human immunodeficiency virus (HIV) transmission. This study evaluates the prevalence of serosorting with casual partners, and analyses the characteristics and estimated numbers of serosorters in Switzerland 2007-2009.

Methods

Data were extracted from cross-sectional surveys conducted in 2007 and 2009 among self-selected MSM recruited online, through gay newspapers, and through gay organizations. Nested models were fitted to ascertain the appropriateness of pooling the datasets. Multiple logistic regression analysis was performed on pooled data to determine the association between serosorting and demographic, lifestyle-related, and health-related factors. Extrapolations were performed by applying proportions of various types of serosorters to Swiss population data collected in 2007.

Results

A significant and stable number of MSM (approximately 39% in 2007 and 2009) intentionally engage in serosorting with casual partners in Switzerland. Variables significantly associated with serosorting were: gay organization membership (aOR = 1.67), frequent internet use for sexual encounters (aOR = 1.71), having had a sexually transmitted infection (STI) at any time in the past 12 months (aOR = 1.70), HIV-positive status (aOR = 0.52), regularly frequenting sex-on-premises venues (aOR = 0.42), and unprotected anal intercourse (UAI) with partners of different or unknown HIV status in the past 12 months (aOR = 0.22). Approximately one-fifth of serosorters declared HIV negativity without being tested in the past 12 months; 15.8% reported not knowing their own HIV status.

Conclusion

The particular risk profile of serosorters having UAI with casual partners (multiple partners, STI history, and inadequate testing frequency) requires specific preventive interventions tailored to HIV status.

Use of a rapid HIV home test prevents HIV exposure in a high risk sample of men who have sex with men

The study assessed whether at-risk HIV-uninfected men who have sex with men (MSM) who never or rarely use condoms and have multiple partners would use a rapid, oral fluid, HIV home test (HT) to screen potential sexual partners. Participants received 16 HT kits, were monitored weekly for 3 months, and then interviewed in depth. Twenty-seven ethnically diverse MSM used HT kits before intercourse with approximately 100 partners in private and public spaces. Testing had high acceptability among ethnic minority participants. Ten tested individuals received HIV-antibody positive results. Seven were potential sexual partners, and three were acquaintances of the participants; six of the ten were unaware of their status. No sexual intercourse took place after positive tests. Very few problems occurred. Most participants strongly desired to continue using HT and to buy it freely. HT use results in detection of previously unknown infections. Making HT available within networks where high-risk sexual practices are common may be a cost-efficient and effective prevention method.

Comparisons of disparities and risks of HIV infection in black and other men who have sex with men in Canada, UK, and USA: a meta-analysis

BACKGROUND

We did a meta-analysis to assess factors associated with disparities in HIV infection in black men who have sex with men (MSM) in Canada, the UK, and the USA.

METHODS

We searched Embase, Medline, Google Scholar, and online conference proceedings from Jan 1, 1981, to Dec 31, 2011, for racial comparative studies with quantitative outcomes associated with HIV risk or HIV infection. Key words and Medical Subject Headings (US National Library of Medicine) relevant to race were cross-referenced with citations pertinent to homosexuality in Canada, the UK, and the USA. Data were aggregated across studies for every outcome of interest to estimate overall effect sizes, which were converted into summary ORs for 106,148 black MSM relative to 581,577 other MSM.

FINDINGS

We analysed seven studies from Canada, 13 from the UK, and 174 from the USA. In every country, black MSM were as likely to engage similarly in serodiscordant unprotected sex as other MSM. Black MSM in Canada and the USA were less likely than other MSM to have a history of substance use (odds ratio, OR, 0·53, 95% CI 0·38-0·75, for Canada and 0·67, 0·50-0·92, for the USA). Black MSM in the UK (1·86, 1·58-2·18) and the USA (3·00, 2·06-4·40) were more likely to be HIV positive than were other MSM, but HIV-positive black MSM in each country were less likely (22% in the UK and 60% in the USA) to initiate combination antiretroviral therapy (cART) than other HIV-positive MSM. US HIV-positive black MSM were also less likely to have health insurance, have a high CD4 count, adhere to cART, or be virally suppressed than were other US HIV-positive MSM. Notably, despite a two-fold greater odds of having any structural barrier that increases HIV risk (eg, unemployment, low income, previous incarceration, or less education) compared with other US MSM, US black MSM were more likely to report any preventive behaviour against HIV infection (1·39, 1·23-1·57). For outcomes associated with HIV infection, disparities were greatest for US black MSM versus other MSM for structural barriers, sex partner demographics (eg, age, race), and HIV care outcomes, whereas disparities were least for sexual risk outcomes.

INTERPRETATION

Similar racial disparities in HIV and sexually transmitted infections and cART initiation are seen in MSM in the UK and the USA. Elimination of disparities in HIV infection in black MSM cannot be accomplished without addressing structural barriers or differences in HIV clinical care access and outcomes.

FUNDING

None.

The cost-effectiveness of preexposure prophylaxis for HIV prevention in the United States in men who have sex with men

BACKGROUND

A recent randomized, controlled trial showed that daily oral preexposure chemoprophylaxis (PrEP) was effective for HIV prevention in men who have sex with men (MSM). The Centers for Disease Control and Prevention recently provided interim guidance for PrEP in MSM at high risk for HIV. Previous studies did not reach a consistent estimate of its cost-effectiveness.

OBJECTIVE

To estimate the effectiveness and cost-effectiveness of PrEP in MSM in the United States.

DESIGN

Dynamic model of HIV transmission and progression combined with a detailed economic analysis.

DATA SOURCES

Published literature.

TARGET POPULATION

MSM aged 13 to 64 years in the United States.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

PrEP was evaluated in both the general MSM population and in high-risk MSM and was assumed to reduce infection risk by 44% on the basis of clinical trial results.

OUTCOME MEASURES

New HIV infections, discounted quality-adjusted life-years (QALYs) and costs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

Initiating PrEP in 20% of MSM in the United States would reduce new HIV infections by an estimated 13% and result in a gain of 550,166 QALYs over 20 years at a cost of $172,091 per QALY gained. Initiating PrEP in a larger proportion of MSM would prevent more infections but at an increasing cost per QALY gained (up to $216,480 if all MSM receive PrEP). Preexposure chemoprophylaxis in only high-risk MSM can improve cost-effectiveness. For MSM with an average of 5 partners per year, PrEP costs approximately $50,000 per QALY gained. Providing PrEP to all high-risk MSM for 20 years would cost $75 billion more in health care-related costs than the status quo and $600,000 per HIV infection prevented, compared with incremental costs of $95 billion and $2 million per infection prevented for 20% coverage of all MSM.

RESULTS OF SENSITIVITY ANALYSIS

PrEP in the general MSM population would cost less than $100,000 per QALY gained if the daily cost of antiretroviral drugs for PrEP was less than $15 or if PrEP efficacy was greater than 75%.

LIMITATION

When examining PrEP in high-risk MSM, the investigators did not model a mix of low- and high-risk MSM because of lack of data on mixing patterns.

CONCLUSION

PrEP in the general MSM population could prevent a substantial number of HIV infections, but it is expensive. Use in high-risk MSM compares favorably with other interventions that are considered cost-effective but could result in annual PrEP expenditures of more than $4 billion.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, Department of Veterans Affairs, and National Institute of Allergy and Infectious Diseases.

[Internet behavior survey about the unprotected anal sex with men who have sex with men]

INTRODUCTION

Unprotected anal sex (insertive or receptive) is an important risk factor for HIV infection and other STDs.

OBJECTIVE

The objective was to investigate individual and social factors associated with unprotected anal sex among Men Who have Sex with Men (MSM) that declared being HIV negative and engaged in anal sex with an HIV positive partner or of ignored serology.

METHODS

This study is part of a survey among MSM and among Internet users, with data collected from an on line questionnaire in project site. The internet sample for this study was 487 MSM. Descriptive and stratified analyses were carried out and χ² test was used. Logistic regression was used for modeling the data.

RESULTS

Among the participants 30.8% referred unprotected anal sex in the previous 12 months with an HIV positive partner or partner with unknown serology. Most of them belonged to higher social classes, were white and single. Factors associated with unprotected anal sex were: number of partners (more than 3) in the previous 12 months (OR=1.7; 95% CI 1.1-2.7), high or medium perception of risk to HIV/Aids (OR=2.7; 95% CI 1.5-3.6) and enjoy passive oral sex (OR=0.3; 95% CI 0.2-0.8).

CONCLUSION

Unprotected anal sex was a frequent practice among MSM in this survey. The frequency to public bathrooms should be further explored as a risk factor for unprotected anal sex. It is important to further explore these findings in order to understand these relationships and the involvement in risky sexual practices for HIV infection among MSM.

Sexually transmitted diseases in men who have sex with men

Men who have sex with men (MSM) have increased rates of human immunodeficiency virus (HIV) infection and sexually transmitted diseases (STDs) compared with demographically matched controls. The reasons for the disproportionate infection burden are complex, including biological, behavioral, and sociocultural factors. HIV and syphilis may often be coprevalent among MSM. The use of nucleic acid amplification testing has enhanced the ability to detect frequently asymptomatic gonococcal and chlamydial infections of the rectum and other sites. Lymphogranuloma proctitis outbreaks among MSM were noted in the developed world several years ago but have not been common recently. MSM are at increased risk for viral hepatitis and anal human papillomavirus disease. Preventive interventions include vaccination for the former and anal cytologic screening for the latter. Because of the diverse ways in which MSM may be exposed to STDs, it is essential for clinicians to obtain a thorough sexual history in a culturally competent manner.

Reasons for not HIV testing, testing intentions, and potential use of an over-the-counter rapid HIV test in an internet sample of men who have sex with men who have never tested for HIV

BACKGROUND

Correlates of main reasons for not HIV testing, HIV testing intentions, and potential use of an over-the-counter rapid HIV test (OTCRT) among men who have sex with men who have never tested for HIV (NTMSM) are unknown.

METHODS

We evaluated these correlates among 946 NTMSM from 6 US cities who participated in an internet-based survey in 2007.

FINDINGS

Main reasons for not testing were low perceived risk (32.2%), structural barriers (25.1%), and fear of testing positive (18.1%). Low perceived risk was associated with having fewer unprotected anal intercourse (UAI) partners and less frequent use of the internet for HIV information; structural barriers were associated with younger age and more UAI partners; fear of testing positive was associated with black and Hispanic race/ethnicity, more UAI partners, and more frequent use of the internet for HIV information. Strong testing intentions were held by 25.9% of all NTMSM and 14.8% of those who did not test because of low perceived risk. Among NTMSM who were somewhat unlikely, somewhat likely, and very likely to test for HIV, 47.4%, 76.5%, and 85.6% would likely use an OTCRT if it was available, respectively.

CONCLUSIONS

Among NTMSM who use the internet, main reasons for not testing for HIV vary considerably by age, race/ethnicity, UAI, and use of the internet for HIV information. To facilitate HIV testing of NTMSM, programs should expand interventions and services tailored to address this variation. If approved, OTCRT might be used by many NTMSM who might not otherwise test for HIV.

Exposure to HIV partner counseling and referral services and notification of sexual partners among persons recently diagnosed with HIV

OBJECTIVE

Among HIV-infected persons, we evaluated use of client partner notification (CPN) and health-department partner notification strategies to inform sex partners of possible HIV exposure, and prior exposure to partner counseling and referral services.

METHODS

We conducted a cross-sectional, observational study of 590 persons diagnosed with HIV in the prior 6 months at 51 HIV test, medical, and research providers in Chicago and Los Angeles in 2003 and 2004. Logistic regression was used to identify independent correlates of using CPN to notify all locatable partners.

RESULTS

Participants reported a total of 5091 sex partners in the 6 months preceding HIV diagnosis; 1253 (24.6%) partners were locatable and not known to be HIV-positive. Of 439 participants with ≥1 locatable partners, 332 (75.6%) reported notifying 696 (55.5%) partners by CPN (585, 84.1%), health-department partner notification (94, 13.5%), or other means (17, 2.4%); 208 (47.4%) used CPN to notify all locatable partners. Independent correlates of CPN included having fewer locatable partners and discussing the need to notify partners with an HIV medical-care provider (black and Hispanic participants only). Many participants reported that their HIV test or medical-care provider did not discuss the need to notify partners (48.8%, 33.7%, respectively) and did not offer health-department partner-notification services (60.8%, 52.8%).

CONCLUSION

Many locatable sex partners who might benefit from being notified of potential HIV exposure are not notified. In accordance with national policies, HIV test and medical-care providers should routinely provide partner counseling and referral services to HIV-infected clients so that all locatable partners are notified and provided an opportunity to learn their HIV status.

Predictors of HIV disclosure among untested, HIV-negative and HIV-positive Australian men who had anal intercourse with their most recent casual male sex partner

We analysed HIV disclosure between Australian men who have sex with men (MSM) who reported anal intercourse with their last casual male partner. Of 804 MSM included in the analysis, 413 reported HIV disclosure and 391 reported no disclosure. After identifying bivariate associations with HIV disclosure, we developed three models of HIV disclosure (one for untested, one for HIV-negative and one for HIV-positive MSM). A range of factors was found to be associated with HIV disclosure. Having previously had sex with the last casual male partner and expecting HIV-negative and HIV-positive men to disclose before sex were predictors of HIV disclosure shared by more than one serostatus group. As unprotected anal intercourse was more common among MSM who disclosed (across all serostatus groups), we suggest caution should be exercised before encouraging HIV disclosure as a prevention strategy. Nondisclosure remains more strongly associated with safe sex among Australian MSM.

The cost-effectiveness of a modestly effective HIV vaccine in the United States

BACKGROUND

The recent RV144 clinical trial showed that an ALVAC/AIDSVAX prime-boost HIV vaccine regimen may confer partial immunity in recipients and reduce transmission by 31%. Trial data suggest that efficacy may initially exceed 70% but decline over the following 3.5 years. Estimating the potential health benefits associated with a one-time vaccination campaign, as well as the projected benefits of repeat booster vaccination, may inform future HIV vaccine research and licensing decisions.

METHODS

We developed a mathematical model to project the future course of the HIV epidemic in the United States under varying HIV vaccine scenarios. The model accounts for disease progression, infection transmission, antiretroviral therapy, and HIV-related morbidity and mortality. We projected HIV prevalence and incidence over time in multiple risk groups, and we estimated quality-adjusted life years (QALYs) and costs over a 10-year time horizon. We assumed an exponentially declining efficacy curve fit to trial data, and that subsequent vaccine boosters confer similar immunity. Variations in vaccine parameters were examined in sensitivity analysis.

RESULTS

Under existing HIV prevention and treatment efforts, an estimated 590,000 HIV infections occur over 10 years. One-time vaccination achieving 60% coverage of adults could prevent 9.8% of projected new infections over 10 years (and prevent 34% of new infections in the first year) and cost approximately $91,000/QALY gained relative to the status quo, assuming $500 per vaccination series. Targeted vaccination strategies result in net cost savings for vaccines costing less than $750. One-time vaccination of 60% of all adults coupled with three-year boosters only for men who have sex with men and people who inject drugs could prevent 21% of infections for $81,000/QALY gained relative to vaccination of higher risk sub-populations only. A program attaining 90% vaccination coverage prevents 15% of new HIV cases over 10 years (and approximately 50% of infections in the first year).

CONCLUSIONS

A partially effective HIV vaccine with effectiveness similar to that observed in the RV144 trial would provide large health benefits in the United States and could meet conventionally accepted cost-effectiveness thresholds. Strategies that prioritize key populations are most efficient, but broader strategies provide greater total population health benefit.

A critical literature review to identify possible causes of higher rates of HIV infection among young black and Latino men who have sex with men

Black and Latino young men who have sex with men (YMSM) are disproportionately impacted by HIV infection; however, the reason for this disparity is unclear. To identify possible causes of the higher rates of HIV infection in this population, data from studies of HIV infection and risk-related behaviors among black and Latino YMSM were used to evaluate a series of hypotheses adapted from Millett et al's literature review that might explain the disparity. High rates of HIV infection might be attributable to unrecognized HIV infection, social/sexual networks, and a history of childhood sexual abuse; however, they were not attributable to risk-related behaviors. More research is needed to understand the risk factors for HIV infection and how to address them in HIV prevention interventions.

The cost-effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States

BACKGROUND

Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment.

OBJECTIVE

To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior.

DESIGN

Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis.

DATA SOURCES

Published literature.

TARGET POPULATION

High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States.

TIME HORIZON

Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]).

PERSPECTIVE

Societal.

INTERVENTION

Expanded HIV screening and counseling, treatment with ART, or both.

OUTCOME MEASURES

New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained.

RESULTS OF SENSITIVITY ANALYSIS

With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%.

LIMITATION

The model of disease progression and treatment was simplified, and acute HIV screening was excluded.

CONCLUSION

Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.

Racial/Ethnic differences in seroadaptive and serodisclosure behaviors among men who have sex with men

We examined racial/ethnic differences in reported seroadaptive and serodisclosure behaviors among the partnerships of MSM recruited for a cross-sectional survey using time-location sampling (TLS) in San Francisco during 2007-2008. The sample (N = 1,199) consisted of 12.2% Asian/Pacific Islander (API), 52.4% White, 6.8% Black, 20.2% Latino, and 8.5% of "other" race/ethnicity. Pure serosorting was most common (about 20%) among HIV-negative men while seropositioning was most used (about 15%) by HIV-positive men. Reported seroadaptive behaviors did not differ significantly across races/ethnicities among both HIV-negative and HIV-positive men. However, HIV-positive Black and Latino men were significantly more likely to report no preventive, seroadaptive behavioral strategy (i.e., unprotected insertive anal intercourse with unknown status or serodiscordant partners). Among men who reported engaging in seroadaptive behaviors, they reported not discussing HIV status with a third of their partners-a major concern in that lack of disclosure undermines the effectiveness and means to practice serosorting. Partnerships of API and Black men were least likely to involve serodisclosure behaviors. Our study confirms that seroadaptive behaviors are common preventive strategies reported by MSM of all races/ethnicities, and does not find strong evidence that racial/ethnic differences in seroadaptive behaviors are enhancing disparities in HIV prevalence. The implications are that condom promotion and safe sex messages are not the only prevention measures adopted by MSM and that public health professionals should be well aware of current trends within the MSM community in order to better assist HIV prevention efforts.

The cost-effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States

BACKGROUND

Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment.

OBJECTIVE

To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior.

DESIGN

Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis.

DATA SOURCES

Published literature.

TARGET POPULATION

High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States.

TIME HORIZON

Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]).

PERSPECTIVE

Societal.

INTERVENTION

Expanded HIV screening and counseling, treatment with ART, or both.

OUTCOME MEASURES

New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained.

RESULTS OF SENSITIVITY ANALYSIS

With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%.

LIMITATION

The model of disease progression and treatment was simplified, and acute HIV screening was excluded.

CONCLUSION

Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.

Elevated HIV prevalence despite lower rates of sexual risk behaviors among black men in the District of Columbia who have sex with men

The District of Columbia (DC) has among the highest HIV/AIDS rates in the United States, with 3.2% of the population and 7.1% of black men living with HIV/AIDS. The purpose of this study was to examine HIV risk behaviors in a community-based sample of men who have sex with men (MSM) in DC. Data were from the National HIV Behavioral Surveillance system. MSM who were 18 years were recruited via venue-based sampling between July 2008 and December 2008. Behavioral surveys and rapid oral HIV screening with OraQuick ADVANCE ½ (OraSure Technologies, Inc., Bethlehem, PA) with Western blot confirmation on positives were collected. Factors associated with HIV positivity and unprotected anal intercourse were identified. Of 500 MSM, 35.6% were black. Of all men, 14.1% were confirmed HIV positive; 41.8% of these were newly identified HIV positive. Black men (26.0%) were more likely to be HIV positive than white (7.9%) or Latino/Asian/other (6.5%) men (p<0.001). Black men had fewer male sex partners than non-black, fewer had ever engaged in intentional unprotected anal sex, and more used condoms at last anal sex. Black men were less likely to have health insurance, have been tested for HIV, and disclose MSM status to health care providers. Despite significantly higher HIV/AIDS rates, black MSM in DC reported fewer sexual risks than non-black. These findings suggest that among black MSM, the primary risk of HIV infection results from nontraditional sexual risk factors, and may include barriers to disclosing MSM status and HIV testing. There remains a critical need for more information regarding reasons for elevated HIV among black MSM in order to inform prevention programming.

Why the wait? Delayed HIV diagnosis among men who have sex with men

We sought to identify factors associated with delayed diagnosis of human immunodeficiency virus (HIV; testing HIV-seropositive 6 months or more after HIV seroconversion), by comparing delayed testers to non-delayed testers (persons who were diagnosed within 6 months of HIV seroconversion), in King County, Washington among men who have sex with men (MSM). Participants were recruited from HIV testing sites in the Seattle area. Delayed testing status was determined by the Serologic Testing Algorithm for Recent HIV Seroconversion or a self-reported previous HIV-negative test. Quantitative data on sociodemographic characteristics, health history, and drug-use and sexual behaviors were collected via computer-assisted self-interviews. Qualitative semi-structured interviews regarding testing and risk behaviors were also conducted. Multivariate analysis was used to identify factors associated with delayed diagnosis. Content analysis was used to establish themes in the qualitative data. Out of the 77 HIV-seropositive MSM in this sample, 39 (51%) had evidence of delayed diagnosis. Factors associated with delayed testing included being African-American, homeless, "out" to 50% or less people about male-male sex, and having only one sex partner in the past 6 months. Delayed testers often cited HIV-related sickness as their reason for testing and fear and wanting to be in denial of their HIV status as reasons for not testing. Delayed testers frequently did not identify as part of the MSM community, did not recognize that they were at risk for HIV acquisition, and did not feel a responsibility to themselves or others to disclose their HIV status. This study illustrates the need to further explore circumstances around delayed diagnosis in MSM and develop outreach methods and prevention messages targeted specifically to this potentially highly marginalized population in order to detect HIV infections earlier, provide HIV care, and prevent new infections.

Characteristics associated with retention among African American and Latino adolescent HIV-positive men: results from the outreach, care, and prevention to engage HIV-seropositive young MSM of color special project of national significance initiative

BACKGROUND

Surveillance points to an urgent public health need for HIV prevention, access, and retention among young men of color who have sex with men (YMSM). The purpose of this multisite study was to evaluate the association between organizational- and individual-level characteristics and retention in HIV care among HIV-positive YMSM of color.

METHODS

Data were collected quarterly via face-to-face interviews and chart abstraction between June 2006 and September 2008. Participants were aged 16-24 years, enrolled at 1 of 8 participating youth-specific demonstration sites, and engaged or reengaged in HIV care within the last 30 days. Generalized estimating equations were used to examine factors associated with missing research and care visits. Stata v.9.0se was used for analysis.

RESULTS

Of 224 participants, the majority were African American (72.7%), 19-22 years old (66.5%), had graduated high school or equivalent (71.8%), identified as gay or homosexual (80.8%), and disclosed having had sex with a man before HIV diagnosis (98.2%). Over the first 2(1/4) years of the study, only 11.4% of visits were missed without explanation or patient contact. Characteristics associated with retention included being <21 years old, a history of depression, receipt of program services, and feeling respected at clinic; those associated with poorer retention included having a CD4 count <200 at baseline and being Latino.

CONCLUSIONS

Special Projects of National Significance programs were able to achieve a high level of retention over time, and individual and program characteristics were associated with retention. Latino YMSM, those not receiving services, and those not perceiving respect at the clinic were at increased risk of falling out of care. Retention is essential to providing HIV+ adolescents with treatment, including reducing antiretroviral resistance development. Innovative programs that address the needs of the YMSM of color population may result in improved retention.

A strategy for selecting sexual partners believed to pose little/no risks for HIV: serosorting and its implications for HIV transmission

A common HIV/AIDS risk reduction strategy among men who have sex with men (MSM) is to limit their unprotected sex partners to those who are of the same HIV status, a practice referred to as serosorting. Decisions to serosort for HIV risk reduction are based on personal impressions and beliefs, and there is limited guidance offered on this community derived strategy from public health services. This paper reviews research on serosorting for HIV risk reduction and offers an evidence-based approach to serosorting guidance. Following a comprehensive electronic and manual literature search, we reviewed 51 studies relating to the implications of serosorting. Studies showed that HIV negative MSM who select partners based on HIV status are inadvertently placing themselves at risk for HIV. Infrequent HIV testing, lack of HIV status disclosure, co-occurring sexually transmitted infections, and acute HIV infection impede the potential protective benefits of serosorting. Public health messages should continue to encourage reductions in numbers of sexual partners and increases in condom use. Risk reduction messages should also highlight the limitations of relying on one's own and partner's HIV status in making sexual risk decisions.

Barriers and facilitators to HIV testing and linkage to primary care: narratives of people with advanced HIV in the Southeast

Persons with unrecognized HIV infection forgo timely clinical intervention and may unknowingly transmit HIV to partners. However, in the USA, unrecognized infection and late diagnosis are common. To understand barriers and facilitators to HIV testing and care, we conducted a qualitative study of 24 HIV infected persons attending a Southeastern HIV clinic who presented with clinically advanced illness. The primary barrier to HIV testing prior to diagnosis was perception of risk; consequently, most participants were diagnosed after the onset of clinical symptoms. While most patients were anxious to initiate care rapidly after diagnosis, some felt frustrated by the passive process of connecting to specialty care. The first visit with an HIV care provider was identified as critical in the coping process for many patients. Implications for the implementation of Centers for Disease Control and Prevention HIV routine screening guidelines are discussed.

Potential population health outcomes and expenditures of HIV vaccination strategies in the United States

Estimating the potential health benefits and expenditures of a partially effective HIV vaccine is an important consideration in the debate about whether HIV vaccine research should continue. We developed an epidemic model to estimate HIV prevalence, new infections, and the cost-effectiveness of vaccination strategies in the U.S. Vaccines with modest efficacy could prevent 300,000-700,000 HIV infections and save $30 billion in healthcare expenditures over 20 years. Targeted vaccination of high-risk individuals is economically efficient, but difficulty in reaching these groups may mitigate these benefits. Universal vaccination is cost-effective for vaccines with 50% efficacy and price similar to other infectious disease vaccines.

Implementation of HIV testing at 2 New York City bathhouses: from pilot to clinical service

BACKGROUND

Commercial sex venues (e.g., bathhouses) that cater to men who have sex with men (MSM) continue to function in most urban areas. These venues present a challenge to developing strategies to prevent the spread of the human immunodeficiency virus (HIV), but they also provide opportunities for interventions to reduce the risk and rate of disease transmission. Several cities in the United States have developed programs that offer HIV testing in these venues. Similar programs have not existed before in New York City.

METHODS

A pilot HIV testing program was implemented at 2 New York City bathhouses. Testing included rapid HIV testing, the use of the serologic testing algorithm for recent HIV seroconversion, and pooled plasma HIV viral load to detect and date incident and acute HIV infections. In addition to HIV tests, behavioral and demographic data were collected from 493 presumed HIV-negative participants.

RESULTS

The pilot program recruited MSM who were at high risk for HIV infection. Of the 493 men tested, 20 (4%) were found to be positive for HIV, and 8 (40%) of these 20 men demonstrated evidence of acute or recent HIV infection. The program tested men often not tested in more traditional medical settings. Significant disparities were demonstrated in the testing habits of MSM who reported having sex with women and had not disclosed same-sex activities to their caregivers.

CONCLUSIONS

Bathhouse-based testing for HIV infection can be implemented in New York City and would include a population of MSM who are at high risk for HIV infection. Because of the high rate of recent HIV infection, expanded testing in these venues may be a good strategy to reduce the forward transmission of HIV in this highly sexually active population.

Estimating the proportion of HIV transmissions from main sex partners among men who have sex with men in five US cities

BACKGROUND

HIV incidence in the United States among men who have sex with men (MSM) has been increasing since 2000, and MSM remain the most heavily impacted risk group in the US HIV epidemic.

METHODS

We modeled HIV transmissions, using data from MSM in five US cities from the National HIV Behavioral Surveillance System, the HIVNET Vaccine Preparedness Study, and other published data. Annual HIV transmissions were estimated by partner type (main or casual) and by sex type (receptive anal intercourse, insertive anal intercourse, or oral sex).

RESULTS

Sixty-eight percent [95% confidence interval (CI) 58-78) of HIV transmissions were from main sex partners because of a higher number of sex acts with main partners, more frequent receptive roles in anal sex with main partners, and lower condom use during anal sex with main partners. By sex type, 69% (95% CI 59-79) of infections were from receptive anal intercourse, 28% (95% CI 19-38) were from insertive anal intercourse, and 2% (95% CI 0-5) were from oral sex. The model-based estimated HIV incidence rate was 2.2% (95% CI 1.7-2.7) per year. Sensitivity analyses demonstrated estimates of transmission from main sex partners as low as 52% (95% CI 41-62) and as high as 74% (95% CI 68-80).

CONCLUSION

According to our model, most HIV transmissions among MSM in five US cities are from main sex partners. HIV prevention efforts should take into account the risks of HIV transmissions in male partnerships, and couples-based HIV prevention interventions for MSM should be given high priority in the US HIV prevention research portfolio.

Behavioral interventions to reduce risk for sexual transmission of HIV among men who have sex with men

BACKGROUND

Men who have sex with men (MSM) remain at great risk for HIV infection. Program planners and policy makers need descriptions of interventions and quantitative estimates of intervention effects to make informed decisions concerning prevention funding and research. The number of intervention strategies for MSM that have been examined with strong research designs has increased substantially in the past few years.

OBJECTIVES

1. To locate and describe outcome studies evaluating the effects of behavioral HIV prevention interventions for MSM.2. To summarize the effectiveness of these interventions in reducing unprotected anal sex.3. To identify study characteristics associated with effectiveness.4. To identify gaps and indicate future research, policy, and practice needs.

SEARCH STRATEGY

We searched electronic databases, current journals, manuscripts submitted by researchers, bibliographies of relevant articles, conference proceedings, and other reviews for published and unpublished reports from 1988 through December 2007. We also asked researchers working in HIV prevention about new and ongoing studies.

SELECTION CRITERIA

Studies were considered in scope if they examined the effects of behavioral interventions aimed at reducing risk for HIV or STD transmission among MSM. We reviewed studies in scope for criteria of outcome relevance (measurement of at least one of a list of behavioral or biologic outcomes, e.g., unprotected sex or incidence of HIV infections) and methodologic rigor (randomized controlled trials or certain strong quasi-experimental designs with comparison groups).

DATA COLLECTION AND ANALYSIS

We used fixed and random effects models to summarize rate ratios (RR) comparing intervention and control groups with respect to count outcomes (number of occasions of or partners for unprotected anal sex), and corresponding prevalence ratios (PR) for dichotomous outcomes (any unprotected anal sex vs. none). We used published formulas to convert effect sizes and their variances for count and dichotomous outcomes where necessary. We accounted for intraclass correlation (ICC) in community-level studies and adjusted for baseline conditions in all studies. We present separate results by intervention format (small group, individual, or community-level) and by type of intervention delivered to the comparison group (minimal or no HIV prevention in the comparison condition versus standard or other HIV prevention in the comparison condition). We examine rate ratios stratified according to characteristics of participants, design, implementation, and intervention content. For small group and individual-level interventions we used a stepwise selection process to identify a multivariable model of predictors of reduction in occasions of or partners for unprotected anal sex. We used funnel plots to examine publication bias, and Q (a chi-squared statistic with degrees of freedom = number of interventions minus 1) to test for heterogeneity.

MAIN RESULTS

We found 44 studies evaluating 58 interventions with 18,585 participants. Formats included 26 small group interventions, 21 individual-level interventions, and 11 community-level interventions. Sixteen of the 58 interventions focused on HIV-positives. The 40 interventions that were measured against minimal to no HIV prevention intervention reduced occasions of or partners for unprotected anal sex by 27% (95% confidence interval [CI] = 15% to 37%). The other 18 interventions reduced unprotected anal sex by 17% beyond changes observed in standard or other interventions (CI = 5% to 27%). Intervention effects were statistically homogeneous, and no independent variable was statistically significantly associated with intervention effects at alpha=.05. However, a multivariable model selected by backward stepwise elimination identified four study characteristics associated with reduction in occasions of or partners for unprotected anal sex among small group and individual-level interventions at alpha=.10. The most favorable reductions in episodes of or partners for unprotected anal sex (33% to 35% decreases) were observed among studies with count outcomes, those with shorter intervention spans (<=1 month), those with better retention in the intervention condition than in the comparison condition, and those with minimal to no HIV prevention intervention delivered to the comparison condition. Because there were only 11 community-level studies we did not search for a multivariable model for community-level interventions. In stratified analyses including only one variable at a time, the greatest reductions (40% to 54% decreases) in number of episodes of or partners for unprotected anal sex among community-level interventions were observed among studies where groups were assigned randomly rather than by convenience, studies with shorter recall periods and longer follow-up, studies with more than 25% non-gay identifying MSM, studies in which at least 90% of participants were white, and studies in which the intervention addressed development of personal skills.

AUTHORS' CONCLUSIONS

Behavioral interventions reduce self-reported unprotected anal sex among MSM. These results indicate that HIV prevention for this population can work and should be supported. Results of previous studies provide a benchmark for expectations in new studies. Meta-analysis can inform future design and implementation in terms of sample size, target populations, settings, goals for process measures, and intervention content. When effects differ by design variables, which are deliberately selected and planned, awareness of these characteristics may be beneficial to future designs. Researchers designing future small group and individual-level studies should keep in mind that to date, effects of the greatest magnitude have been observed in studies that used count outcomes and a shorter intervention span (up to 1 month). Among small group and individual-level studies, effects were also greatest when the comparison condition included minimal to no HIV prevention content. Nevertheless, statistically significant favorable effects were also seen when the comparison condition included standard or other HIV prevention content. Researchers choosing the latter option for new studies should plan for larger sample sizes based on the smaller expected net intervention effect noted above. When effects differ by implementation variables, which become evident as the study is conducted but are not usually selected or planned, caution may be advised so that future studies can reduce bias. Because intervention effects were somewhat stronger (though not statistically significantly so) in studies with a greater attrition in the comparison condition, differential retention may be a threat to validity. Extra effort should be given to retaining participants in comparison conditions. Among community-level interventions, intervention effects were strongest among studies with random assignment of groups or communities. Therefore the inclusion of studies where assignment of groups or communities was by convenience did not exaggerate the summary effect. The greater effectiveness of interventions including more than 25% non-gay identifying MSM suggests that when they can be reached, these men may be more responsive than gay-identified men to risk reduction efforts. Non-gay identified MSM may have had less exposure to previous prevention messages, so their initial exposure may have a greater impact. The greater effectiveness of interventions that include efforts to promote personal skills such as keeping condoms available and behavioral self-management indicates that such content merits strong consideration in development and delivery of new interventions for MSM. And the finding that interventions were most effective for majority white populations underscores the critical need for effective interventions for MSM of African and Latino descent. Further research measuring the incidence of HIV and other STDs is needed. Because most studies were conducted among mostly white men in the US and Europe, more evaluations of interventions are needed for African American and Hispanic MSM as well as MSM in the developing world. More research is also needed to further clarify which behavioral strategies (e.g., reducing unprotected anal sex, having oral sex instead of anal sex, reducing number of partners, avoiding serodiscordant partners, strategic positioning, or reducing anal sex even with condom use) are most effective in reducing transmission among MSM, the messages most effective in promoting these behaviors, and the methods and settings in which these messages can be most effectively delivered.

Sexual risk taking among young internet-using men who have sex with men

OBJECTIVES

We examined the characteristics of young Internet-using men who have sex with men (MSM) and risks associated with seeking sex online, offline, or through both strategies.

METHODS

Data were obtained from MSM aged 18 to 24 years who completed a 45-minute online survey regarding sex and Internet use in the preceding 3 months.

RESULTS

Significantly more Internet-using MSM who had met sexual partners both online and offline (43%) reported unprotected anal intercourse than did those who had met sexual partners exclusively online (29%) or offline (34%). MSM who met sexual partners exclusively offline reported the fewest partners but the greatest proportion of partnerships involving unprotected anal intercourse (49%). Meeting sexual partners both online and offline (odds ratio [OR]=3.38-58.42) and being drunk (OR=1.57) or high (OR=2.24) increased the odds of having more sexual partners. The same factors increased the odds of having unprotected anal intercourse (online and offline sexual partners, OR=1.60; being drunk, OR=1.43; being high, OR=1.61).

CONCLUSIONS

Risky sexual behavior was prevalent among all of the study subgroups. Our findings suggest that online sex seeking is associated with greater numbers of sexual partners but neither promotes nor discourages unprotected anal intercourse. Regardless of where sexual partners met, being drunk and high were significant risks for unprotected anal intercourse.

Condom Use Rather Than Serosorting Explains Differences in HIV Incidence Among Men Who Have Sex With Men

BACKGROUND

HIV incidence is high and increasing among men who have sex with men (MSM) attending the Sexually Transmitted Infection (STI) Outpatient Clinic in Amsterdam but remains low among MSM in the Amsterdam Cohort Studies (ACS). We studied whether sexual behaviors in these 2 groups are consistent with serosorting and if serosorting explains the difference in HIV incidence.

METHODS

In 2004 to 2006, a survey of sexual behaviors and HIV status regarding up to 4 traceable partners in the prior 6 months was performed in MSM attending the STI Outpatient Clinic (high-risk) and in MSM in the ACS (lower risk). Moreover, pooled information was collected on anonymous partners. We used logistic regression to test whether sexual behaviors are consistent with serosorting and to test whether risk group is associated with having concordant traceable partners among men reporting unprotected anal intercourse (UAI).

RESULTS

We included 513 MSM (54% lower risk and 75% HIV-negative). Lower risk and high-risk MSM with concordant traceable partners were more likely to have UAI than MSM with discordant partners or partners of unknown HIV status (P < 0.001). Risk group was not associated with having concordant UAI. Compared with lower risk MSM, however, high-risk MSM frequently had UAI with nonconcordant traceable partners and with anonymous partners.

CONCLUSIONS

Sexual risk behaviors with traceable partners are consistent with serosorting. Nonetheless, the higher level of UAI with anonymous or nonconcordant traceable partners more likely explains the increasing HIV incidence seen among STI Outpatient Clinic attendees than a difference in serosorting behavior.

Serosorting can potentially increase HIV transmissions

The effectiveness of a serosorting strategy for HIV prevention depends on the accuracy of individuals' serostatus disclosures. We modeled the risks of sexual transmission of HIV under various circumstances differing by the type of disclosures made. Accounting for rates of unrecognized HIV infection, treatment status and differences in infectivity by stage of infection, we found that serosorting can increase the transmission risk for some groups.