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Condoms continue to be used by many gay, bisexual, and other men who have sex with men (GBM) to reduce the risk of HIV transmission. However this is impacted by condom failure events, defined here as condom breakage and slippage. In a prospective, observational cohort study of 343 HIV serodiscordant male couples recruited through high HIV caseload clinics and hospitals between 2012 and 2016 in Australia, Brazil, and Thailand, condom failure rates and associated factors were analysed, including with the study partner versus other sexual partners. There were 717 reported instances of condom failure from an estimated total of 25,831 sex acts with condoms, from over 588.4 participant years of follow up. Of the HIV-negative partners (n = 343) in the study, more than a third (n = 117, 36.7%) reported at least one instance of condom failure with any partner type during study follow-up. Condom failure with their study partner was reported by 91/343 (26.5%) HIV-negative partners, compared with 43/343 (12.5%) who reported condom failure with other partners. In total, there were 86 events where the HIV-negative partner experienced ano-receptive condom failure with ejaculation, representing 12.0% of all failure events. In multivariable analysis, compared to Australia, HIV-negative men in Brazil reported a higher incidence risk rate of condom failure (IRR = 1.64, 95%CI 1.01–2.68, p = 0.046) and HIV-negative men who reported anal sex with other partners reported an increased risk of condom failure compared with men who only had sex with their study partner (IRR = 1.89, 95%CI 1.08–3.33, p = 0.025). Although at least one event of condom failure was reported by a significant proportion of participants, overall condom failure events represented a small proportion of the total condom protected sex acts. [ABSTRACT FROM AUTHOR]

Alternatives to daily dosing of HIV pre-exposure prophylaxis (PrEP) are continuing to emerge. From October 2019 to March 2020, we conducted an online survey of PrEP-experienced gay and bisexual men in Australia about interest in and preference for four different PrEP modalities: daily dosing, event-driven dosing, long-acting injectable (LAI)-PrEP and subdermal PrEP implants. Using data from 1477 participants, we measured interest and preference of different modalities using multivariate logistic regression. High proportions of participants were interested in LAI-PrEP (59.7%), daily PrEP (52.0%), PrEP implants (45.3%) and event-driven PrEP (42.8%). LAI-PrEP was the most frequently selected preference (30.5%), followed by PrEP implants (26.3%), daily PrEP (21.4%) and event-driven PrEP (21.2%). Higher interest and preference for non-daily PrEP modalities were associated with being concerned about side effects and perceived difficulties with daily adherence. As novel modalities emerge, attitudes to them should be considered in public health messaging to facilitate informed decision-making. [ABSTRACT FROM AUTHOR]

Few studies have examined changes in sexual behaviour following HIV pre-exposure prophylaxis (PrEP) initiation among gay, bisexual and other men who have sex with men (GBM) in relationships. In a national, online, prospective study of GBM in Australia, we compared sexual behaviours prior to and after PrEP initiation among HIV-negative and unknown-HIV-status men (recruited 2014–2017) not taking PrEP at baseline and who completed at least one six-monthly follow-up by July 2018. Among men in relationships who did not initiate PrEP (n = 339), we compared their most recent survey to their prior one, while among men in relationships who initiated PrEP (n = 81), we compared follow-ups before and after PrEP initiation. Among the 81 PrEP-initiators who were in a relationship both before and after initiation, the proportion reporting their regular partner was on PrEP increased from 8.3 to 44.4% (p < 0.001) and the proportion reporting receptive CLAIC increased from 27.2 to 44.4% (p = 0.009). Overall, men who initiated PrEP were more likely to be in a relationship with a partner on PrEP, and it appeared they started PrEP around the same time. Receptive CLAIC also became more common. [ABSTRACT FROM AUTHOR]

Increasing HIV testing frequency in gay and bisexual men (GBM) is critical to reducing the time between HIV infection and diagnosis. Using anonymous national behavioural surveillance data (2013–2018) from 43,753 surveys of Australian GBM, we examined HIV testing frequency trends and factors differentiating PrEP-users, non-PrEP-users reporting two or more tests in the previous year, and non-PrEP-users reporting less frequent testing. The proportion tested at least annually increased from 64.4% in 2013 to 70.8% in 2018 (p-trend < 0.001), and from 73.9% to 84.6% among the 51.6% of men classified as higher-risk. Among higher-risk men, having two or more tests in the previous year increased from 48.0% to 69.3% (p-trend < 0.001). Among higher-risk non-PrEP-users, it increased from 47.2% to 54.8% (p-trend < 0.001), however, there was a decrease since 2016 (p-trend < 0.001). Among PrEP-users, it increased from 82.1% in 2013 to 97.3% in 2018 (p-trend < 0.001). Non-PrEP-using higher-risk men having less frequent tests reported lower risk than PrEP-users and non-PrEP-using men reporting two or more tests in the previous year. However, recent risk behaviour was not uncommon: nearly half reported condomless sex; one-fifth reported receptive condomless sex with ejaculation; over half reported group sex; one-quarter used drugs for the purposes of sex; and one-fifth had more than ten sex partners. Efforts are needed to encourage frequent testing and PrEP use among non-PrEP-users who are at higher-risk. [ABSTRACT FROM AUTHOR]

Data from repeated, national behavioural HIV surveillance was used to identify similarities and differences between young gay and bisexual men (YGBM) aged 16–24 (n = 1608) and older GBM aged 25–49 (n = 6266), in order to quantify risks and identify gaps in HIV prevention. Trend analyses from 2014 to 2018 are also reported. While there were similar rates of condomless anal intercourse with casual partners in both age groups, YGBM had lower rates of HIV testing and PrEP use but also fewer male partners. Our results suggest most YGBM have lower HIV risk than older GBM but a minority merit enhanced testing and prevention efforts. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: We determined the contribution of undiagnosed HIV to new infections among gay and bisexual men (GBM) over a 12‐year period in Australia where there has been increasing focus on improving testing and HIV treatment coverage. Methods: We generated annual estimates for each step of the HIV cascade and the number of new HIV infections for GBM in Australia over 2004 to 2015 using relevant national data. Using Bayesian melding we then fitted a quantitative model to the cascade and incidence estimates to infer relative transmission coefficients associated with being undiagnosed, diagnosed and not on ART, on ART with unsuppressed virus, or on ART with suppressed virus. Results: Between 2004 and 2015, we estimated the percentage of GBM with HIV in Australia who were unaware of their status to have decreased from 14.5% to 7.5%. During the same period, there was a substantial increase in the number and proportion of GBM living with HIV on treatment and with suppressed virus, with the number of virally suppressed GBM increasing from around 3900 (30.2% of all GBM living with HIV) in 2004 to around 14,000 (73.7% of all GBM living with HIV) in 2015. Despite the increase in viral suppression, the annual number of new infections rose from around 660 to around 760 over this period. Our results have a wide range due to the uncertainty in the cascade estimates and transmission coefficients. Nevertheless, undiagnosed GBM increasingly appear to contribute to new infections. The proportion of new infections attributable to undiagnosed GBM almost doubled from 33% in 2004 to 59% in 2015. Only a small proportion (<7%) originated from GBM with suppressed virus. Discussion: Our study suggests that an increase in HIV treatment coverage in Australia has reduced the overall risk of HIV transmission from people living with HIV. However, the proportion of infections and the rate of transmission from undiagnosed GBM has increased substantially. These findings highlight the importance of HIV testing and intensified prevention for Australian GBM at high risk of HIV. [ABSTRACT FROM AUTHOR]

Background: Condomless anal intercourse (CLAI) has long been recognized as the primary mode of sexual transmission of HIV in gay and other men who have sex with men (MSM). A variety of measures of CLAI have been commonly used in behavioral surveillance for HIV risk and to forecast trends in HIV infection. However, gay and other MSM's sexual practices changed as the understanding of disease and treatment options advance. In the present paper, we argue that summary measures such as "any CLAI" do not accurately measure HIV sexual risk behavior. Methods: Participants were 1,427 HIV-negative men from the Health in Men cohort study run from 2001 to 2007 in Sydney, Australia, with six-monthly interviews. At each interview, detailed quantitative data on the number of episodes of insertive and receptive CLAI in the last 6 months were collected, separated by partner type (regular vs. casual) and partners' HIV status (negative, positive, and HIV status unknown). Results: A total of 228,064 episodes of CLAI were reported during the study period with a mean of 44 episodes per year per participant (median: 14). The great majority of CLAI episodeswere with a regular partner (92.6%), most of them with HIV-negative regular partners (84.8%). Participants were more likely to engage in insertive CLAI with casual than with regular partners (66.7 vs. 55.3% of all acts of CLAI with each partner type, p <0.001). Men were more likely to report CLAI in the receptive position with HIV-negative and HIV status unknown partners than with HIV-positive partners (p <0.001 for both regular and casual partners). Conclusion: Gay and other MSM engaging in CLAI demonstrate clear patterns of HIV risk reduction behavior. As HIV prevention enters the era of antiretroviral-based biomedical approach, using all forms of CLAI indiscriminately as a measure of HIV behavioral risk is not helpful in understanding the current drivers of HIV transmission in the community. [ABSTRACT FROM AUTHOR]

Background. Circumcision status was examined as an independent risk factor for sexually transmissible infections (STIs) in the Health in Men cohort of homosexual men in Sydney. Methods. From 2001 through 2004, 1427 initially human immunodeficiency virus (HIV)-negative men were enrolled and followed up until mid-2007. All participants were offered annual STI testing. The history of STIs was collected at baseline, and information on sexual risk behaviors was collected every 6 months. At annual faceto- face visits, participants reported STI diagnoses received during the previous year. Results. Circumcision was not associated with prevalent or incident herpes simplex virus 1, herpes simplex virus 2, or self-reported genital warts. There was also no independent association of circumcision with incident urethral gonorrhea or chlamydia. Being circumcised was associated with a significantly reduced risk of incident (hazard ratio, 0.35 [95% confidence interval, 0.15-0.84]) but not prevalent (odds ratio, 0.71 [95% confidence interval, 0.35-1.44]) syphilis. The association was somewhat stronger among men who reported predominantly insertive unprotected anal intercourse (hazard ratio, 0.10 [95% confidence interval, 0.01-0.82]). Conclusions. These are the first prospective data obtained from homosexual men to assess circumcision status as a risk factor for STIs. Circumcised men were at reduced risk of incident syphilis but no other prevalent or incident STIs. Circumcision is unlikely to have a substantial public health impact in reducing acquisition of most STIs in homosexual men. [ABSTRACT FROM AUTHOR]

Background. Despite increasing reports of herpes simplex virus (HSV) type 1 (HSV-1)-associated anogenital herpes, there are very limited data comparing the seroepidemiological profile of and risk factors for HSV-1 and 0HSV type 2 (HSV-2) infection. Methods. Sexual behaviors were examined as risk factors for prevalent and incident HSV-1 and HSV-2 infections in a community-based cohort of 1427 HIV-negative gay men in Australia. Results. The prevalence of HSV-1 and HSV-2 at baseline was 75% and 23%, respectively. The rate of prevalent infection with HSV-1, as well as the rate of prevalent infection with HSV-2, was much lower in individuals <25 years of age, and each type of infection was associated with a higher number of both male and female sex partners. The median duration of follow-up of the cohort was 2.0 years. Among participants who were susceptible to infection, the incidence rates for HSV-1 and HSV-2 infection were 5.58 and 1.45 cases per 100 person-years, respectively. In multivariate analysis, incident infection with HSV-1 was significantly associated with younger age (P =.027) and reports of frequent insertive oral sex with casual partners (hazard ratio, 3.91 [95% confidence interval, 1.23–12.44]; P = .021 ). Incident infection with HSV-2 was significantly associated with a variety of anal sex practices with casual partners. Conclusions. Both HSV-1 and HSV-2 were commonly sexually transmitted, and there were more HSV-1 than HSV-2 seroconversions. Public-health strategies targeted against anogenital herpes increasingly need to take into account the importance of HSV-1 infection. [ABSTRACT FROM AUTHOR]

Introduction: There are few data about the range of strategies used to prevent sexual HIV transmission within gay male serodiscordant couples. We examined HIV prevention strategies used by such couples and compared differences between countries. Methods: Opposites Attract was a cohort study of male serodiscordant couples in Australia, Brazil and Thailand, from May 2014 (Australia) or May 2016 (Brazil/Thailand) to December 2016. At visits, HIV‐positive partners had viral load (VL) tested; HIV‐negative partners reported sexual behaviour and perceptions of their HIV‐positive partner's VL results. Within‐couple acts of condomless anal intercourse (CLAI) were categorized by strategy: condom‐protected, biomedically protected (undetectable VL and/or pre‐exposure prophylaxis [PrEP]), or not protected by either (HIV‐negative partners engaging in insertive CLAI, receptive CLAI with withdrawal, or receptive CLAI with ejaculation). Results: A total of 343 couples were included in this analysis (153 in Australia, 93 in Brazil and 97 in Thailand). Three‐quarters of HIV‐positive partners were consistently virally suppressed (<200 copies/mL) during follow‐up, and HIV‐negative partners had correct perceptions of their partner's VL result for 76.5% of tests. One‐third of HIV‐negative partners used daily PrEP during follow‐up. Over follow‐up, 73.8% of couples had CLAI. HIV‐negative partners reported 31,532 acts of anal intercourse with their HIV‐positive partner. Of these, 46.7% were protected by condoms, 48.6% by a biomedical strategy and 4.7% of acts were not protected by these strategies. Australian couples had fewer condom‐protected acts and a higher proportion of biomedically protected acts than Brazilian and Thai couples. Of the 1473 CLAI acts where the perceived VL was detectable/unknown and were not protected by PrEP (4.7% of all acts), two‐thirds (n = 983) were when the HIV‐negative partner was insertive (strategic positioning). Of the 490 acts when the HIV‐negative partner was receptive, 261 involved withdrawal and 280 involved ejaculation. Thus, <1% of acts were in the highest risk category of receptive CLAI with ejaculation. Conclusions: Couples used condoms, PrEP or perceived undetectable VL for prevention in the majority of anal intercourse acts. Only a very small proportion of events were not protected by these strategies. Variation between countries may reflect differences in access to HIV treatment, education, knowledge and attitudes. [ABSTRACT FROM AUTHOR]

The article presents a report on the prevalence and predictors for high-grade anal intraepithelial neoplasia (HGAIN) in community-based cohorts of human immunodeficiency virus (HIV)-negative and HIV-positive homosexual men in Sydney, Australia. The researchers performed a cross-sectional study of consecutive participants in both cohorts, 204 HIV-negative and 128 HIV-positive men, in 2005. The study found that HGAIN was prevalent in homosexual men across all age groups and was more than twice as common in HIV-positive men compared with HIV-negative men.

The article presents a study which investigates the lymphogranuloma venereum (LGV) in community-based groups of HIV-infected and -uninfected men who have sex with men (MSM) in Sydney, Australia. The study uses the LGV typing on all Chlamydia trachomatis DNA-positive specimens to examine whether there is an asymptomatic pool of LGV in the community. The results show that the LGV typing of Chlamydia infections in asymptomatic Australian MSM is not justified in the community.

Background: Event-driven pre-exposure prophylaxis (ED-PrEP), when taken according to the "2-1-1" dosing method, is highly effective at preventing HIV acquisition for gay, bisexual, and other men who have sex with men (GBM). Any missed doses when using ED-PrEP drastically reduce its effectiveness, so it is vital that people using this method know how to take it correctly. This study investigated Australian GBM's awareness of ED-PrEP and their knowledge of how to take it correctly., Method: We conducted a survey of 1471 PrEP-experienced GBM in Australia, between October 2019 and March 2020. The survey assessed awareness and knowledge of the 3 components of the "2-1-1" ED-PrEP dosing regimen (number of pills for loading dose, timing of loading dose, and number of days after sex to take PrEP pills) among GBM. Characteristics associated with ED-PrEP awareness and correct knowledge of how to take ED-PrEP were assessed with multivariate logistic regression., Results: Two-thirds (n = 1004, 68.4%) had heard of ED-PrEP, of whom only one-eighth (n = 125, 12.5%) knew the correct details of the "2-1-1" ED-PrEP method; one-third (n = 339, 33.8%) did not know any of the 3 key components. Awareness of ED-PrEP and correct knowledge was associated with greater belief in PrEP efficacy, university education, and intention to take a nondaily PrEP regimen in the next 6 months., Conclusions: Although ED-PrEP awareness was considerable, most participants did not know how to use ED-PrEP correctly. Further work is needed to increase awareness and knowledge of ED-PrEP among GBM., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

We examined depression and anxiety prior to and during COVID-19 restrictions in Australian gay and bisexual men (GBM). In an online cohort, a COVID-19-focused survey was conducted in April 2020. During 2019 and in April 2020, 664 GBM completed the Patient Health Questionnaire (PHQ-9, measuring depression) and Generalized Anxiety Disorder Assessment (GAD-7, measuring anxiety). Increased depression and anxiety were defined as a ≥ 5 point increase on the respective scales. Mean PHQ-9 and GAD-7 scores increased between 2019 and 2020 (PHQ-9: from 5.11 in 2019 to 6.55 in 2020; GAD-7: from 3.80 in 2019 to 4.95 in 2020). The proportion of participants with moderate-severe depression (PHQ-9 ≥ 10) increased from 18.8% (n = 125) to 25.5% (n = 169), while the proportion of participants with moderate-severe anxiety (GAD-7 ≥ 10) increased from 12.7% (n = 84) to 17.3% (n = 115). Almost one-quarter of participants (n = 158, 23.8%) had increased depression; in these men, mean PHQ-9 increased from 2.49 in 2019 to 11.65 in 2020 (p < 0.001). One-in-five (20.6%) participants (n = 137) had increased anxiety; among these men, mean GAD-7 increased from 2.05 in 2019 to 10.22 in 2020 (p < 0.001). Increases were associated with concerns about job security, reduction in social and sexual connections and opportunities, and being personally concerned about COVID-19 itself. COVID-19 appeared to have a sudden and pronounced impact on depression and anxiety in Australian GBM, with a significant minority showing sharp increases. Ongoing monitoring is required to determine longer-term impacts and GBM need access to appropriate and sensitive supports both during and after the COVID-19 pandemic., (© 2022. The Author(s).)

Recreational drug use (RDU) among gay and bisexual men (GBM) is associated with higher-risk sexual behaviours, however this has not been well defined among older GBM. We investigated the association between RDU and sexual behaviours among older GBM in Sydney, Australia. 617 GBM aged 35-79 years self-reported their RDU in the past 6 months and sexual behaviours. Age-stratified univariable associations between RDU and behaviour were examined. GBM aged 35-44 years were the most likely to report RDU, with rates decreasing with increasing age (Ptrend < 0.001). Associations between RDU and higher-risk sexual behaviours were most consistently found among GBM aged 35-54 years.

Background: HIV pre-exposure prophylaxis (PrEP) is a highly effective biomedical HIV prevention strategy, yet some gay and bisexual men (GBM) who are eligible to access PrEP are not using it. We report the incidence of PrEP uptake, factors predicting its initiation, and identify characteristics associated with nonuptake of PrEP among Australian GBM who meet the eligibility criteria., Methods: The Following Lives Undergoing Change (Flux) Study is a national, online, prospective observational study among GBM focusing on licit and illicit drug use. Participants (N = 1257) responded to baseline and 6-monthly follow-up questionnaires. Incidence per 100 person-years and incidence rate ratios of PrEP initiation are presented. Multivariate Poisson regression was used to examine associations with PrEP initiation and logistic regression to examine associations with nonuptake of PrEP among eligible GBM., Results: Among GBM who met the eligibility criteria, 69.8% of men did not commence PrEP. Factors independently associated with nonuptake of PrEP were younger age, living in an Australian state without a PrEP trial, lower social engagement with other gay men, less use of illicit party drugs or use of illicit party drugs for sex, and less likely to have engaged in HIV sexual risk behaviors such as group sex or any condomless anal intercourse., Conclusions: Despite meeting formal eligibility criteria for PrEP, men who were relatively less sexually active or less socially connected were less likely to initiate PrEP. Men who did not initiate PrEP may assess their risk as insufficient relative to others to warrant using PrEP because they engaged in less frequent "risky" behaviors.

Background: Evidence on viral load and HIV transmission risk in HIV-serodiscordant male homosexual couples is limited to one published study. We calculated transmission rates in couples reporting condomless anal intercourse (CLAI), when HIV-positive partners were virally suppressed, and daily pre-exposure prophylaxis (PrEP) was not used by HIV-negative partners., Methods: In the Opposites Attract observational cohort study, serodiscordant male homosexual couples were recruited from 13 clinics in Australia, one in Brazil, and one in Thailand. At study visits, HIV-negative partners provided information on sexual behaviour and were tested for HIV and sexually transmitted infections; HIV-positive partners had HIV viral load tests, CD4 cell count, and sexually transmitted infection tests done. Viral suppression was defined as less than 200 copies per mL. Linked within-couple HIV transmissions were identified with phylogenetic analysis. Incidence was calculated per couple-year of follow-up, focusing on periods with CLAI, no use of daily PrEP, and viral suppression. One-sided upper 95% CI limits for HIV transmission rates were calculated with exact Poisson methods., Findings: From May 8, 2012, to March 31, 2016, in Australia, and May 7, 2014, to March 31, 2016, in Brazil and Thailand, 358 couples were enrolled. 343 couples had at least one follow-up visit and were followed up for 588·4 couple-years. 258 (75%) of 343 HIV-positive partners had viral loads consistently less than 200 copies per mL and 115 (34%) of 343 HIV-negative partners used daily PrEP during follow-up. 253 (74%) of 343 couples reported within-couple CLAI during follow-up, with a total of 16 800 CLAI acts. Three new HIV infections occurred but none were phylogenetically linked. There were 232·2 couple-years of follow-up and 12 447 CLAI acts in periods when CLAI was reported, HIV-positive partners were virally suppressed, and HIV-negative partners did not use daily PrEP, resulting in an upper CI limit of 1·59 per 100 couple-years of follow-up for transmission rate., Interpretation: HIV treatment as prevention is effective in men who have sex with men. Increasing HIV testing and linking to immediate treatment is an important strategy in HIV prevention in homosexual men., Funding: National Health and Medical Research Council; amfAR, The Foundation for AIDS Research; ViiV Healthcare; and Gilead Sciences., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: We report prevalence and incidence of drug use initiation in Australian gay and bisexual men (GBM) participating in an online cohort study., Methods: Between September 2014 and June 2015, 1,710 GBM were enrolled in the Following Lives Undergoing Change Study and followed-up six monthly. Participants were asked about measures of lifetime use at baseline and recent use (last six months) at all visits. Drug use initiation was defined as men who reported having never used a specific drug prior to baseline and reported recent use at follow-up., Results: Participants' median age was 31 years (range: 16-81). Prevalence of lifetime use was significantly associated with older age for all individual drugs (p trend<0.001), and 84.1% reported lifetime use of any drugs. Just above half (51.9%) reported recent use at baseline, with the majority reporting occasional use (once or twice in the previous six-months). Among men who reported no history of drug use at baseline, drug initiation was highest for amyl nitrite, with an incidence of 10.5 per 100 person-years (95% CI 7.9-13.9), followed by cannabis (7.3 per 100 person-years, 95% CI 5.0-10.6) and ecstasy (5.0 per 100 person-years, 95% CI 3.6-7.0). Younger age was significantly associated with higher incidence of initiation of amyl nitrite, ecstasy, cocaine, ketamine, GHB, and LSD (p trend <0.05 for all)., Conclusion: Prevalence of lifetime illicit drug use is lower in younger GBM than in their older counterparts. However, incidence of drug use initiation is high among younger men, providing an opportunity for early intervention., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background Regular sexual partnerships among gay and bisexual men (GBM) who practice condomless anal intercourse (CLAI) have not been well characterised in terms of partnership type, HIV seroconcordance and risk of HIV transmission. Primarily sexual regular partnerships, although commonly reported by gay men, have largely been ignored in research and HIV prevention. Among regular partners reporting CLAI with each other, we determined factors differentiating romantic or committed relationships from partnerships organised primarily around sex ('fuckbuddies') and estimated the proportion of CLAI presenting risk for HIV transmission., Methods: An online, cross-sectional survey of Australian GBM was conducted. Univariate and multivariate generalised estimating equations were used to determine statistical associations., Results: Men reported on 2250 regular sexual partnerships. Over half the partnerships were romantic or committed relationships. Over half the partnerships were HIV-negative seroconcordant (54.9%), 3.1% were HIV-positive seroconcordant, 5.2% were serodiscordant and 36.8% were of unknown seroconcordance. Potential risks presented by CLAI were sometimes mitigated by protective factors, such as having a clear spoken agreement about sex with outside partners, having fewer outside partners, openly discussing HIV risk and having an agreement to reduce risk from outside partners. These protective factors were more often found in romantic or committed relationships than among primarily sexual partnerships, and were less often found in partnerships of unknown seroconcordance., Conclusion: CLAI is more common among regular sexual partnerships considered to be of a romantic, committed nature. However, factors associated with such romantic or committed partnerships can also protect against HIV transmission risk. Unknown seroconcordance, particularly lack of communication about HIV status among primarily sexual partnerships, is a key risk factor that needs to be addressed by HIV education.

In many countries, including Australia, policies have recently changed to support HIV self-testing. The decision has created much debate about the public health benefits of the strategy versus the risks. Self-testing for HIV was approved in the US on the basis that it would facilitate greater HIV testing uptake, despite having a lower sensitivity than laboratory HIV immunoassays. We calculated the frequency of self-testing that would be required among Australian gay and bisexual men at high-risk for there to be a public health benefit (detection of HIV infections that would have otherwise remained undiagnosed). At a population level, if access to HIV self-testing led to men supplementing their usual sexual health check-ups (involving a laboratory HIV immunoassay) with one or more self-tests at home, or self-tests led to untested gay and bisexual men having an HIV test for the first time, there would be a public health benefit. If men replaced their average of one laboratory HIV immunoassay per year with self-testing at home, then three self-tests would be needed to counteract the lower sensitivity of the self-test (so zero infections would be missed). If four self-tests were undertaken then additional infections would be detected (ie, there would be a public health benefit). Additional public health benefits include a reduction in the period of undiagnosed infection, which is known to be a period of relatively high infectiousness.

Background: Human papillomavirus 16 (HPV16) has been causally associated with approximately 70% of anal cancers. This cancer is markedly increasing among homosexual men. There is limited knowledge of the epidemiology and natural history of anal HPV infection in homosexual men., Methods: Behavioral data and sera for antibodies to HPV16 L1 were collected annually for 1427 HIV-negative and 245 HIV-positive Australian homosexual men. Seroprevalence, seroincidence, and risk factors were calculated., Results: Among HIV-negative men, 25.4% were HPV16 seropositive at baseline compared with 44.3% of HIV-positive men. HPV16 seroincidence was 3.1/100 person-years among HIV-negative men and 1.3/100 person-years among HIV-positive men. Seroincidence among HIV-negative men remained >3% per year until 45 years of age, before declining. In multivariate analyses of data from HIV-negative men, seroprevalent HPV16 was associated with sexual risk behaviors and seropositivity for several viral sexually transmissible infections. Seroincident HPV16 was associated with younger age and unprotected anal intercourse with HIV-positive partners. Among men who predominantly practiced insertive anal intercourse, circumcision was associated with a 57% reduction in seroincident HPV16 (hazard ratio = 0.43, 95% confidence interval: 0.21-0.88, P = 0.021)., Conclusions: HPV16 seroincidence remained common in men until their mid 40s suggesting that vaccination may be protective in sexually active young gay men. Both HPV16 seroprevalence and seroincidence correlated well with markers of higher risk sexual activity, particularly receptive anal sexual practices. An association between circumcision and decreased HPV16 seroconversion in HIV-negative men who preferred the insertive position in anal sex was observed.

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.

Background: Over the last decade, syphilis epidemics have resurged around the world, particularly among gay men. An innovative public health response could be the use of chemoprophylaxis. We sought out to determine the acceptability of syphilis chemoprophylaxis and its likely population effectiveness if it were adopted., Methods: We conducted a mixed-methods study. An online survey (n = 2095 participants) and focus groups (n = 23 participants) were conducted to determine whether syphilis chemoprophylaxis is likely to be acceptable to gay men in Australia. We also developed an individual-based mathematical model that simulated a population of gay men, to explore the potential impact of introducing chemoprophylaxis., Results: Of the 2095 gay men surveyed, 52.7% (95% confidence interval, 50.6%-54.8%) indicated that they would be very likely or slightly likely to use chemoprophylaxis to reduce their chance of acquiring syphilis, increasing to 75.8% (95% confidence interval, 74.0%-77.6%) if chemoprophylaxis would help reduce infections in the gay community. In this model, 70% use-effectiveness of chemoprophylaxis used by 50% of gay men is expected to reduce the number of syphilis cases by ∼50% after 12 months and 85% after 10 years. The majority of the prevention efforts can be gained by targeting subpopulations of men with higher sexual activity., Conclusions: Chemoprophylaxis offers promise as an acceptable and effective intervention for mitigating syphilis epidemics. The outcomes of a planned placebo-controlled syphilis chemoprophylaxis trial are eagerly anticipated.

Background: The incidence of syphilis infections has been substantially increasing in gay men in the developed world., Methods: We developed an individual-based mathematical model describing syphilis transmission within a gay male population: we used the model to simulate the expected relative impact of numerous screening and treatment interventions, targeting different at-risk groups with various coverage and frequency rates and follow-up schedules., Results: The model predicts that increasing the proportion of gay men tested each year would have a relatively modest impact on syphilis incidence. However, increasing the frequency of testing can have a large impact, with the prevalence of syphilis reduced substantially if individuals are tested every 3 months. Targeting frequent screening at gay men who have large numbers of partners or who engage in group sex is a more efficient way of reducing syphilis epidemics. Contact tracing the regular partners of infected individuals is the most efficient intervention and can have a significant epidemiological impact with relatively high coverage rates., Conclusions: Increasing the frequency of testing and treatment are required to mitigate syphilis epidemics. Notifying and testing partners of infected men should occur where possible but the high rates required to reverse epidemic trends are likely to be infeasible. Contact tracing should be a secondary priority that is coupled with increases in the frequency of testing in the population. Encouraging testing among men not previously tested for syphilis is also recommended.

Objective: The objective of this study is to estimate per-contact probability of HIV transmission in homosexual men due to unprotected anal intercourse (UAI) in the era of HAART., Design: Data were collected from a longitudinal cohort study of community-based HIV-negative homosexual men in Sydney, Australia., Methods: A total of 1427 participants were recruited from June 2001 to December 2004. They were followed up with 6-monthly detailed behavioral interviews and annual testing for HIV till June 2007. Data were used in a bootstrapping method, coupled with a statistical analysis that optimized a likelihood function for estimating the per-exposure risks of HIV transmission due to various forms of UAI., Results: During the study, 53 HIV seroconversion cases were identified. The estimated per-contact probability of HIV transmission for receptive UAI was 1.43% [95% confidence interval (CI) 0.48-2.85] if ejaculation occurred inside the rectum, and it was 0.65% (95% CI 0.15-1.53) if withdrawal prior to ejaculation was involved. The estimated transmission rate for insertive UAI in participants who were circumcised was 0.11% (95% CI 0.02-0.24), and it was 0.62% (95% CI 0.07-1.68) in uncircumcised men. Thus, receptive UAI with ejaculation was found to be approximately twice as risky as receptive UAI with withdrawal or insertive UAI for uncircumcised men and over 10 times as risky as insertive UAI for circumcised men., Conclusion: Despite the fact that a high proportion of HIV-infected men are on antiretroviral treatment and have undetectable viral load, the per-contact probability of HIV transmission due to UAI is similar to estimates reported from developed country settings in the pre-HAART era.

While the HIV epidemic is resurging in gay communities worldwide, HIV notification rates remain stable in NSW. This outcome demonstrates the success of a well-funded partnership approach to preventing HIV infection in gay men in NSW. However, population rates of new diagnoses of HIV are similar to those seen in comparable countries and sexual risk-taking may be increasing. As the HIV epidemic has evolved, prevention in gay men has become more complex and must effectively engage with an increasing diversity of risk reduction strategies. These strategies reflect the continual adaptation of the gay community to evolving understandings of the HIV epidemic and the diverse ways in which gay men balance pleasure and prevention.

Background: We examined a range of common bacterial and viral sexually transmitted infections as risk factors for HIV seroconversion in a community-based cohort of HIV-negative homosexual men in Sydney, Australia., Methods: Detailed information about HIV risk behaviors was collected by interview twice yearly. Participants were tested annually for HIV, anal and urethral gonorrhea and chlamydia, herpes simplex virus types 1 and 2, and syphilis. In addition, they reported annual diagnoses of these conditions and of genital and anal warts., Results: Among 1427 enrolled participants, 53 HIV seroconverters were identified, giving an incidence of 0.78 per 100 person-years. After controlling for number of episodes of insertive and receptive nonseroconcordant unprotected anal intercourse, there were independent associations with anal gonorrhea (adjusted hazard ratio = 7.12, 95% confidence interval: 2.05 to 24.79) and anal warts (hazard ratio = 3.63, 95% confidence interval: 1.62 to 8.14)., Conclusions: Anal gonorrhea and anal warts were independently associated with HIV acquisition. The added HIV prevention value of more frequent screening of the anus to allow early detection and treatment of anal sexually transmitted infections in homosexual men should be considered.

Objective: To assess circumcision status as a risk factor for HIV seroconversion in homosexual men., Design, Setting and Participants: The Health in Men (HIM) study was a prospective cohort of homosexual men in Sydney, Australia. HIV-negative men (n = 1426) were recruited primarily from community-based sources between 2001 and 2004 and followed to mid-2007. Participants underwent annual HIV testing, and detailed information on sexual risk behaviour was collected every 6 months., Main Outcome Measure: HIV incidence in circumcised compared with uncircumcised participants, stratified by whether or not men predominantly practised the insertive role in anal intercourse., Results: There were 53 HIV seroconversions during follow-up; an incidence of 0.78 per 100 person-years. On multivariate analysis controlling for behavioural risk factors, being circumcised was associated with a nonsignificant reduction in risk of HIV seroconversion [hazard ratio 0.78, 95% confidence interval (CI) 0.42-1.45, P = 0.424]. Among one-third of study participants who reported a preference for the insertive role in anal intercourse, being circumcised was associated with a significant reduction in HIV incidence after controlling for age and unprotected anal intercourse (UAI) (hazard ratio 0.11, 95% CI 0.03-0.80, P = 0.041). Those who reported a preference for the insertive role overwhelmingly practised insertive rather than receptive UAI., Conclusions: Overall, circumcision did not significantly reduce the risk of HIV infection in the HIM cohort. However, it was associated with a significant reduction in HIV incidence among those participants who reported a preference for the insertive role in anal intercourse. Circumcision may have a role as an HIV prevention intervention in this subset of homosexual men.

Among 746 participants in the Three or More Study (TOMS) of gay men who engaged in group sex in the previous 6 months, 22.4% reported unprotected anal intercourse (UAI) with any partners they did not know to be the same HIV serostatus as themselves. Not knowing oneself to be HIV-negative, not having a clear intention to use condoms, and more frequent group sex were independently associated with UAI. This study shows that gay men who engage in group sex represent an important priority for targeted HIV prevention activities and research.

Introduction: The relevance of circumcision in preventing male-to-male sexual transmission of HIV is poorly understood, in particular because any potential beneficial effect could be diminished by the impact of circumcision on sexual behavior., Aim: We examined the impact of circumcision on sexual experience., Methods: Univariate and multivariate logistic regressions were performed on data from 1,426 HIV-negative homosexually active men., Main Outcome Measures: We compared the sexual behaviors and preferences of circumcised with uncircumcised men, and men who were circumcised at infancy with those who were circumcised after infancy., Results: Overall, 66% of men (N = 939) in the cohort were circumcised. After adjusting for age and ethnicity, we found no differences between circumcised and uncircumcised men in any insertive or receptive anal intercourse, difficulty using condoms, or sexual difficulties (e.g., loss of libido). Among the circumcised men, we compared those circumcised at infancy (N = 854) with those circumcised after infancy (N = 81). The majority cited phimosis (i.e., an inability to fully retract the foreskin) and parents' decision as the main reasons for circumcision after infancy. After adjusting for age and ethnicity, the men circumcised after infancy were more likely to practice any receptive anal sex (88% vs. 75%, P < 0.05) and to experience erection difficulties (52% vs. 47%, P < 0.05), but less likely to practice any insertive anal sex (79% vs. 87%, P < 0.05) and to experience premature ejaculation (15% vs. 23%, P < 0.05) than those circumcised at infancy., Conclusions: Our data suggest that overall circumcision status does not affect the HIV-negative gay men's anal sexual behaviors, experience of condom use, or likelihood of sexual difficulties. However, there is some suggestion of differences in sexual practices and preferences among circumcised gay men depending on the age at circumcision. In particular, gay men circumcised later are more likely to engage in and prefer receptive anal intercourse.

Objectives: A range of HIV risk reduction strategies has been described in homosexual men who practice unprotected anal intercourse (UAI), including serosorting, strategic positioning, and negotiating around an HIV-positive partner's viral load. It is uncertain how commonly these behaviors might result in HIV infection. We describe sexual behaviors and associated risk reduction strategies reported by homosexual men in their accounts of their recent seroconversion., Methods: Homosexual men recently diagnosed with primary HIV infection between 2003 and 2006 were invited to participate in a nurse-administered survey., Results: Among 158 men enrolled, 143 (91%) were able to identify the high-risk event that they believed led to their HIV seroconversion, and this involved UAI in 102 (71%). Among these 102 men, 21 (21%) reported they were certain that the source partner was HIV-negative. Ten men (10%) reported insertive UAI as the highest risk behavior. Of the 21 men who reported knowing the HIV-positive partner's viral load, 9 reported that the man had an undetectable viral load (43%)., Conclusion: In 38% of the high-risk events involving UAI, infection occurred when the reported risk event involved serosorting, strategic positioning, or intercourse with a man whose viral load was believed to be undetectable.

Objectives: To determine any differences in HIV-risk and drug-use behaviour among Aboriginal and Torres Strait Islander gay men and other gay men in Australia., Methods: The Gay Community Periodic Survey is a repeated cross-sectional prevalence study of the sexual and drug use behaviours of Australian gay men conducted since 1996. Responses from Aboriginal and Torres Strait Islander (ATSI) gay men were compared with those from non-ATSI gay men for the years 2000-2004., Results: Of 34 708 responses collected in major Australian cities over a 6-year period, 1208 identified as Aboriginal or Torres Strait Islander. There was little difference between ATSI and non-ATSI men in the reported prevalence of HIV, though ATSI gay men were more likely than non-ATSI gay men to engage in unprotected anal intercourse with casual partners and to inject illicit drugs but were more likely to have been recently tested for HIV CONCLUSIONS: These ATSI gay men were at increased risk of HIV and other blood-borne viruses, though this may be due to differences in socio-economic status as much as cultural background. These findings indicate the continued need for targeted sexual and injecting-drug-use health interventions among this population.

In recent years, increases in both risk behavior and in seroconversion among homosexually active men have been noted in a number of parts of the world. Data were available from 903 HIV negative homosexual men regarding number of acts of unprotected anal intercourse (UAI), separated into receptive and insertive UAI, with and without ejaculation, with steady and with casual partners. Partners were classified according to serostatus as reported by respondents. Men (N = 325) reported 13,692 UAI acts, most of which were with steady partners, of whom most were reported to be HIV-negative. With HIV-positive partners, both steady and casual, and with casual partners of unknown serostatus, receptive UAI with ejaculation was relatively rare. Insertive UAI without ejaculation was relatively common with casual partners of unknown serostatus. Patterns of UAI suggest that risk of transmission may be greater with steady partners. Men appear to modify practice according to both the nature of the relationship (steady or casual) and (assumed) serostatus of partner.