Incorrect Knowledge of Event-Driven PrEP "2-1-1" Dosing Regimen Among PrEP-Experienced Gay and Bisexual Men in Australia.

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.

Increase in Depression and Anxiety Among Australian Gay and Bisexual Men During COVID-19 Restrictions: Findings from a Prospective Online Cohort Study.

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.

Preferences for Current and Future PrEP Modalities Among PrEP-Experienced Gay and Bisexual Men in Australia.

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.

High Levels of Prevention-Effective Adherence to HIV PrEP: An Analysis of Substudy Data From the EPIC-NSW Trial.

BACKGROUND: Preexposure prophylaxis (PrEP) prevents HIV infection but relies on good adherence at times of risk, termed "prevention-effective adherence." Most studies assess adherence without reference to sexual behaviur, making it challenging to determine if poor adherence coincides with HIV risk. SETTING: We examined data from a behavioral substudy of a large-scale PrEP implementation trial in New South Wales, Australia. METHODS: Trial participants completed optional brief quarterly surveys, reporting the number of pills taken and sexual behavior with male partners for each day of the "last full week" before each survey. Condomless sex (CLS) was defined as "higher risk" for HIV when with HIV-positive men with detectable/unknown viral loads or unknown HIV status men. Adequate PrEP protection was defined as ≥4 pills for participants assigned male sex at birth and ≥6 pills for participants assigned female sex at birth (including transgender men). RESULTS: Of 9596 participants dispensed PrEP, 4401 completed baseline and ≥1 follow-up survey. Participants reported on 12,399 "last full weeks": 7485 weeks (60.4%) involved CLS and 2521 weeks (33.7% of CLS-weeks) involved higher risk CLS. There were 103 weeks in which participants did not have adequate PrEP protection and had higher risk CLS: 4.1% of higher-risk CLS weeks (n = 103/2521), 1.4% of all CLS weeks (n = 103/7485), and 0.8% of all observed weeks (n = 103/12,399). CONCLUSIONS: In a large PrEP trial, prevention-effective adherence to PrEP was very high at 99%. Our findings illustrate the importance of measuring pill-taking and sexual behavior in the same period so that prevention-effective adherence can be better estimated.

Changes in Sexual Behaviour Following PrEP Initiation Among Australian Gay and Bisexual Men in Relationships: Results from a Prospective Observational Study.

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.

Effect of age on the association between recreational drug use and sexual risk behaviour: a cross-sectional observational analysis.

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.

Increases in HIV Testing Frequency in Australian Gay and Bisexual Men are Concentrated Among PrEP Users: An Analysis of Australian Behavioural Surveillance Data, 2013-2018.

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.

Assessing the HIV Prevention Needs of Young Gay and Bisexual Men in the PrEP Era: An Analysis of Trends in Australian Behavioural Surveillance, 2014-2018.

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.

HIV Pre-exposure Prophylaxis (PrEP) Uptake Among Gay and Bisexual Men in Australia and Factors Associated With the Nonuse of PrEP Among Eligible Men: Results From a Prospective Cohort Study.

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.

Strategies used by gay male HIV serodiscordant couples to reduce the risk of HIV transmission from anal intercourse in three countries.

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.

Viral suppression and HIV transmission in serodiscordant male couples: an international, prospective, observational, cohort study.

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.

Age-related prevalence and twelve-month incidence of illicit drug use in a cohort of Australian gay and bisexual men: Results from the Flux Study.

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.

Undiagnosed HIV infections among gay and bisexual men increasingly contribute to new infections in Australia.

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.

How partnership type and HIV seroconcordance affect HIV transmission risk in regular sexual partnerships: a cross-sectional survey of Australian gay and bisexual men.

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.

Following Lives Undergoing Change (Flux) study: Implementation and baseline prevalence of drug use in an online cohort study of gay and bisexual men in Australia.

BACKGROUND: Drug use among gay and bisexual men (GBM) is higher than most populations. The use of crystal methamphetamine, erectile dysfunction medication (EDM), and amyl nitrite have been associated with sexual risk behaviour and HIV infection among gay and bisexual men (GBM). OBJECTIVE: This paper describes an online prospective observational study of licit and illicit drug use among GBM and explores baseline prevalence of drug use in this sample. Capturing these data poses challenges as participants are required to disclose potentially illegal behaviours in a geographically dispersed country. To address this issue, an entirely online and study specific methodology was chosen. METHODS: Men living in Australia, aged 16.5 years of age or older, who identified as homosexual or bisexual or had sex with at least one man in the preceding 12 months were eligible to enrol. RESULTS: Between September 2014 and July 2015, a total of 2250 participants completed the baseline questionnaire, of whom, 1710 (76.0%) consented to six-monthly follow-up. The majority (65.7%) were recruited through Facebook targeted advertising. At baseline, over half (50.5%) the men reported the use of any illicit drug in the previous six months, and 28.0% had used party drugs. In the six months prior to enrolment, 12.0% had used crystal methamphetamine, 21.8% had used EDM, and 32.1% had used amyl nitrite. Among the 1710 men enrolled into the cohort, 790 men had used none of these drugs. CONCLUSION: Ease of entry and minimal research burden on participants helped ensure successful recruitment into this online cohort study. Study outcomes will include the initiation and cessation of drug use, associated risk behaviours, and health consequences, over time. Results will provide insights into the role gay community plays in patterns of drug use among GBM.

The Meaning of 'Regular Partner' in HIV Research Among Gay and Bisexual Men: Implications of an Australian Cross-Sectional Survey.

Estimates of the proportion of HIV infections coming from within regular sexual relationships among gay and bisexual men (GBM) vary widely. Research surveys use various partner type categories, but there is little understanding of how men classify their partners. We conducted an online cross-sectional survey of Australian GBM exploring sexual relationships, including 2057 men reporting on 2566 regular partnerships. Just over half of the partnerships were considered 'relationships', while the remainder were non-romantic 'fuckbuddy'-style arrangements. In multivariable analysis, factors associated with considering the partnership a 'relationship' were: using a 'romantic' descriptor, partnership length, monogamous agreements, any condomless anal sex with each other, love, and commitment. The category of 'regular partner' can mask diverse partnership types, which have different meanings to GBM, associated behaviours, and HIV risks. Certain HIV prevention techniques may be more suited to particular types of partnerships. 'Fuckbuddy' arrangements need to be more explicitly acknowledged in HIV prevention.

Willingness to Act upon Beliefs about 'Treatment as Prevention' among Australian Gay and Bisexual Men.

HIV 'treatment as prevention' (TasP) is highly effective in reducing HIV transmission in serodiscordant couples. There has been little examination of gay and bisexual men's attitudes towards TasP, particularly regarding men's willingness to act on beliefs about TasP. We conducted an online cross-sectional survey of Australian men in late 2012 to investigate knowledge and beliefs about new developments in HIV prevention. Amongst 839 men (mean age 39.5 years), men tended to disagree that TasP was sufficiently effective to justify reduced condom use, although HIV-positive men had more favourable attitudes. Only a minority of men were aware of any evidence for TasP; and one-quarter incorrectly believed that evidence for the effectiveness of TasP already existed for the homosexual population. One-fifth (20.5%) of men reported that they would be willing to have condomless anal intercourse with an opposite-status sexual partner when the HIV-positive partner was taking HIV treatments. Factors independently associated with such willingness were: HIV-positive serostatus, reporting any serodiscordant or serononconcordant condomless anal intercourse with a regular male partner in the previous six months, reporting any condomless anal intercourse with a casual male partner in the previous six months, and having greater beliefs in the effectiveness of TasP. This indicated that the men most willing to rely on TasP to prevent transmission were already engaging in higher risk practices. Biomedical HIV prevention represents a rapidly changing environment with new research as well as community and policy responses emerging at a fast pace. For men with serodiscordant sexual partners to successfully apply TasP to reducing transmission risk, more support and education is needed to enable better utilisation of TasP in specific relational and sexual contexts.

Homosexual men in HIV serodiscordant relationships: implications for HIV treatment as prevention research.

INTRODUCTION: Studies in heterosexual HIV serodiscordant couples have provided critical evidence on the role of HIV treatments in reducing HIV transmission risk. However, there are limited data regarding the effect of treatment on HIV transmission in homosexual male couples. We examined features of male homosexual HIV serodiscordant relationships that may impact upon the design of HIV treatment and transmission studies. METHODS: Data were from a prospective cohort study of HIV-negative homosexual men in Sydney, Australia. Men were followed up with six-monthly interviews and annual testing for HIV. Characteristics of men in HIV serodiscordant and seroconcordant relationships at baseline were compared, and a longitudinal analysis performed of rate of relationship break-up and of HIV incidence. RESULTS: At baseline, 5.5% of participants (n=79) had an HIV-positive partner. Most (80.8%) of these relationships were non-monogamous, and 36.7% of men reported recent unprotected anal intercourse (UAI) with casual partners. The rate of relationship break-up was 29.5 per 100 person-years. Half of men in serodiscordant relationships (49.4%) reported recent UAI with their regular partners. HIV incidence was 2.2 per 100 person-years. It was substantially higher in relationships of less than one year's duration (6.1 per 100 person-years) and in men who reported unprotected receptive anal intercourse with ejaculation with their regular partners (15.5 per 100 person-years). CONCLUSIONS: Levels of HIV transmission risk and incidence were high, particularly in early relationships. Rates of relationship break-up were high. These data suggest that studies of HIV treatments and transmission in homosexual serodiscordant couples should focus on early relationships so as not to underestimate risk, and sample sizes must allow for high rates of relationship break-up.

Potential public health benefits of HIV testing occurring at home in Australia.

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.

"Any Condomless Anal Intercourse" is No Longer an Accurate Measure of HIV Sexual risk Behavior in Gay and Other Men Who have Sex with Men.

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 episodes were 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.