Multicentre double-blind randomised placebo-controlled trial evaluating the efficacy of the meningococcal B vaccine, 4CMenB (Bexsero), against Neisseria gonorrhoeae infection in men who have sex with men: the GoGoVax study protocol.

INTRODUCTION: Gonorrhoea, the sexually transmissible infection caused by Neisseria gonorrhoeae, has a substantial impact on sexual and reproductive health globally with an estimated 82 million new infections each year worldwide. N. gonorrhoeae antimicrobial resistance continues to escalate, and disease control is largely reliant on effective therapy as there is no proven effective gonococcal vaccine available. However, there is increasing evidence from observational cohort studies that the serogroup B meningococcal vaccine four-component meningitis B vaccine (4CMenB) (Bexsero), licensed to prevent invasive disease caused by Neisseria meningitidis, may provide cross-protection against the closely related bacterium N. gonorrhoeae. This study will evaluate the efficacy of 4CMenB against N. gonorrhoeae infection in men (cis and trans), transwomen and non-binary people who have sex with men (hereafter referred to as GBM+). METHODS AND ANALYSIS: This is a double-blind, randomised placebo-controlled trial in GBM+, either HIV-negative on pre-exposure prophylaxis against HIV or living with HIV (CD4 count >350 cells/mm3), who have had a diagnosis of gonorrhoea or infectious syphilis in the last 18 months (a key characteristic associated with a high risk of N. gonorrhoeae infection). Participants are randomised 1:1 to receive two doses of 4CMenB or placebo 3 months apart. Participants have 3-monthly visits over 24 months, which include testing for N. gonorrhoeae and other sexually transmissible infections, collection of demographics, sexual behaviour risks and antibiotic use, and collection of research samples for analysis of N. gonorrhoeae-specific systemic and mucosal immune responses. The primary outcome is the incidence of the first episode of N. gonorrhoeae infection, as determined by nucleic acid amplification tests, post month 4. Additional outcomes consider the incidence of symptomatic or asymptomatic N. gonorrhoeae infection at different anatomical sites (ie, urogenital, anorectum or oropharynx), incidence by N. gonorrhoeae genotype and antimicrobial resistance phenotype, and level and functional activity of N. gonorrhoeae-specific antibodies. ETHICS AND DISSEMINATION: Ethical approval was obtained from the St Vincent's Hospital Human Research Ethics Committee, St Vincent's Hospital Sydney, NSW, Australia (ref: 2020/ETH01084). Results will be disseminated in peer-reviewed journals and via presentation at national and international conferences. TRIAL REGISTRATION NUMBER: NCT04415424.

A proposal for a simplified measure of HIV preexposure prophylaxis prevention-effective adherence in self-report questionnaires.

Evaluating HIV preexposure prophylaxis (PrEP) use and HIV risk events concurrently remains challenging. We developed a single question method for measuring prevention-effective adherence with PrEP in self-report questionnaires. In a questionnaire completed by 409 gay and bisexual men, 46% reported condomless anal sex that was not covered by their own PrEP use, and this was more common among younger, lower-income participants. Refining this questionnaire item could improve measurement of prevention-effective adherence.

Sexual pleasure and HIV-related worry in female sex workers on oral pre-exposure prophylaxis in south-western Uganda.

BACKGROUND: Female sex workers (FSWs) contribute disproportionately to HIV transmission in Uganda, and pre-exposure prophylaxis (PrEP) is effective in preventing HIV among cisgender women. Psychological factors are important for PrEP uptake, but few studies have examined psychosocial changes due to PrEP use in Uganda. METHODS: In 2021, we recruited 524 FSWs in three Trans-African Highway towns and four fishing communities in south-western Uganda. We conducted structured interviews among women who were attending routine PrEP follow-up visits in six health units. Bivariable and multivariable modified regression using a robust covariance matrix estimator were used to identify factors associated with experiencing increased sexual pleasure and less worry about HIV because of PrEP. RESULTS: Overall, 80.9% participants reported that sex was more pleasurable because of taking PrEP. There were statistical trends for sex being more pleasurable when taking PrEP or when having condomless sex with casual paying partners (aPR=1.19, 95% CI=1.07-1.32, P =0.001). Almost three-quarters of the participants (76.3%) were less worried about getting HIV because of PrEP. Condomless sex with casual paying partners (aPR=1.17, 95% CI=1.05-1.31, P =0.032, P =0.003) and being On PrEP for the past 1-2years (aPR=1.18, 95% CI=1.00-1.38, P =0.032) was significantly associated with HIV-related worry (aPR=1.17, 95% CI=1.05-1.31, P =0.032, P =0.003) Conclusions : We found a positive impact of PrEP in Ugandan FSWs on two key psychosocial dimensions: (1) more pleasurable sex; and (2) less worry about acquiring HIV. Interventions aiming to increase PrEP uptake may find it useful to focus on psychosocial dimensions.

Human papillomavirus and p16INK4a in oropharyngeal squamous cell carcinomas: A systematic review and meta-analysis.

We intended to update human papillomavirus (HPV) prevalence and p16INK4a positivity in oropharyngeal squamous cell carcinomars (SCC), and calculate HPV attributable fraction (AF) for oropharyngeal SCC by geographic region. We searched Medline, Embase, and the Cochrane Library to identify published studies of HPV prevalence and p16INK4a positivity alone or together in oropharyngeal SCC before December 28, 2021. Studies that reported type-specific HPV DNA prevalence using broad-spectrum PCR-based testing methods were included. We estimated pooled HPV prevalence, type-specific HPV prevalence, and p16INK4a positivity. AF of HPV was calculated by geographic region. One hundred and thirty-four studies including 12 139 cases were included in our analysis. The pooled HPV prevalence estimate for oropharyngeal SCC was 48.1% (95% confidence interval [CI] 43.2-53.0). HPV prevalence varied significantly by geographic region, and the highest HPV prevalence in oropharyngeal SCC was noted in North America (72.6%, 95% CI 63.8-80.6). Among HPV positive cases, HPV 16 was the most common type with a prevalence of 40.2% (95% CI 35.7-44.7). The pooled p16INK4a positivity in HPV positive and HPV16 positive oropharyngeal SCC cases was 87.2% (95% CI 81.6-91.2) and 91.7% (84.3-97.2). The highest AFs of HPV and HPV16 were noted in North America at 69.6% (95% CI 53.0-91.5) and 63.0% (48.0-82.7). [Correction added on 31 October 2023, after first online publication: the percentage symbol (%) was missing and has been added to 63.0% (48.0-82.7) in the Abstract and Conclusion.] A significant proportion of oropharyngeal SCC was attributable to HPV. HPV16 accounts for the majority of HPV positive oropharyngeal SCC cases. These findings highlight the importance of HPV vaccination in the prevention of a substantial proportion of oropharyngeal SCC cases.

Trends in Testing and Self-Reported Diagnoses of Sexually Transmitted Infections in Gay and Bisexual Men in Australia, 2017 to 2021: Analysis of National Behavioral Surveillance Surveys.

BACKGROUND: Gay, bisexual, and other men who have sex with men (GBM) are overrepresented in diagnoses of sexually transmitted infections (STIs) relative to their population size. This study assessed trends in STI testing and diagnoses among GBM in Australia. METHODS: The Gay Community Periodic Surveys are repeated cross-sectional behavioral surveillance surveys of GBM. Participants reported the number of anal swabs, throat swabs, urine samples, and blood tests for syphilis they undertook in the last year. "Frequent comprehensive testing" was defined as ≥3 of each test in the previous year. Participants reported STI diagnoses of chlamydia, gonorrhea, syphilis, and other STIs in the last year. Trends in testing and diagnoses from 2017 to 2020 and 2020 to 2021 were assessed with logistic regression models. RESULTS: We analyzed 24,488 survey responses from participants reporting casual sex in the last 6 months. Between 2017 and 2020, frequent comprehensive STI testing decreased among HIV-negative GBM on preexposure prophylaxis (PrEP) from 71.7% to 68.9% and declined further to 58.6% in 2021. Frequent comprehensive STI testing was stable during 2017-2020 among HIV-negative/untested GBM not on PrEP (17.4%-14.6%) and HIV-positive GBM (30.4%-35.1%) but declined in 2021 to 7.5% among non-PrEP-users and 25.7% among HIV-positive participants. There were minimal changes in STI diagnoses during 2017-2020, but diagnoses declined in 2021. CONCLUSIONS: Many GBM do not meet Australian STI testing guidelines that recommend quarterly testing. Further evaluation of whether this recommendation is realistic or necessary to reduce STIs among GBM is recommended.

Improving access to oral pre-exposure prophylaxis for HIV among international migrant populations.

Pre-exposure prophylaxis (PrEP) is recommended for people susceptible to HIV acquisition, and the scale-up of PrEP programmes has contributed to new HIV case reductions at a population level. However, international migrants continue to be disproportionately affected by HIV. Understanding barriers and facilitators to PrEP implementation among international migrants can optimise PrEP use among this population and ultimately reduce HIV incidence worldwide. We reviewed the evidence regarding factors influencing PrEP implementation among international migrants; 19 studies were included. The barriers and facilitators at the individual level were related to knowledge and risk perception of HIV. Cost, provider discriminations, and health system navigation influenced PrEP use at the service level. Positive or negative perception towards LGBT+ identities, HIV, and PrEP users affected PrEP use at the societal level. Most existing PrEP campaigns do not target international migrants; therefore, culturally tailored approaches for people from different backgrounds are warranted. Potentially migration-related and HIV-related discriminatory policies must be reviewed to increase access to HIV prevention services to end HIV transmission at a population level.

The application of new metrics for understanding trends in undiagnosed HIV among key populations.

OBJECTIVE: Investigate the utility of novel metrics for understanding trends in undiagnosed HIV. METHODS: We produced estimates for the number of people with undiagnosed HIV and the number of new HIV infections using Australian surveillance data and the European Centre for Disease Prevention and Control HIV modelling tool. Using these estimates, we calculated: the total diagnosed fraction, the proportion of all people with HIV diagnosed; the yearly diagnosed fraction, the proportion of people who have not yet received a diagnosis who received a diagnosis during each year; and the case detection rate, which is the annual ratio of new HIV diagnoses to new HIV infections each year; from 2008 to 2019. We report trends in these metrics for Australian-born and overseas-born men who reported male-to-male sex and heterosexual women and men. RESULTS: Each metric for the Australian-born male-to-male sexual contact group improved consistently. In contrast, the metrics for the overseas-born group worsened (total diagnosed fraction: 85.0-81.9%, yearly diagnosed fraction: 23.1-17.8%, and case detection rate: 0.74-0.63). In heterosexuals, women and men had consistent increasing trends for the total diagnosed fraction and yearly diagnosed fraction but with women having consistently higher estimates. Heterosexual men had a declining case detection rate, falling to less than one in 2011, compared to an increase for women. CONCLUSIONS: The additional metrics provided important information on Australia's progress toward HIV elimination. The more dynamic changes in the undiagnosed population seen highlight diverging trends for key populations not seen in the total diagnosed fraction.

HIV treatment-as-prevention and its effect on incidence of HIV among cisgender gay, bisexual, and other men who have sex with men in Australia: a 10-year longitudinal cohort study.

BACKGROUND: Although HIV treatment-as-prevention reduces individual-level HIV transmission, population-level effects are unclear. We aimed to investigate whether treatment-as-prevention could achieve population-level reductions in HIV incidence among gay, bisexual, and other men who have sex with men (GBM) in Australia's most populous states, New South Wales and Victoria. METHODS: TAIPAN was a longitudinal cohort study using routine health record data extracted from 69 health services that provide HIV diagnosis and care to GBM in New South Wales and Victoria, Australia. Data from Jan 1, 2010, to Dec 31, 2019, were linked within and between services and over time. TAIPAN collected data from all cisgender GBM who attended participating services, resided in New South Wales or Victoria, and were 16 years or older. Two cohorts were established: one included HIV-positive patients, and the other included HIV-negative patients. Population prevalence of viral suppression (plasma HIV viral load <200 RNA copies per µL) was calculated by combining direct measures of viral load among the HIV-positive cohort with estimates for undiagnosed GBM. The primary outcome of HIV incidence was measured directly via repeat testing in the HIV-negative cohort. Poisson regression analyses with generalised estimating equations assessed temporal associations between population prevalence of viral suppression and HIV incidence among the subsample of HIV-negative GBM with multiple instances of HIV testing. FINDINGS: At baseline, the final sample (n=101 772) included 90 304 HIV-negative and 11 468 HIV-positive GBM. 59 234 patients in the HIV-negative cohort had two or more instances of HIV testing and were included in the primary analysis. Over the study period, population prevalence of viral suppression increased from 69·27% (95% CI 66·41-71·96) to 88·31% (86·37-90·35), while HIV incidence decreased from 0·64 per 100 person-years (95% CI 0·55-0·76) to 0·22 per 100 person-years (0·17-0·28). Adjusting for sociodemographic characteristics and HIV pre-exposure prophylaxis (PrEP) use, treatment-as-prevention achieved significant population-level reductions in HIV incidence among GBM: a 1% increase in population prevalence of viral suppression corresponded with a 6% decrease in HIV incidence (incidence rate ratio [IRR] 0·94, 95% CI 0·93-0·96; p<0·0001). PrEP was introduced in 2016 with 17·60% uptake among GBM that year, which increased to 36·38% in 2019. The relationship between population prevalence of viral suppression and HIV incidence was observed before the availability of PrEP (IRR 0·98, 95% CI 0·96-0·99; p<0·0001) and was even stronger after the introduction of PrEP (0·80, 0·70-0·93; p=0·0030). INTERPRETATION: Our results suggest that further investment in HIV treatment, especially alongside PrEP, can improve public health by reducing HIV incidence among GBM. FUNDING: National Health and Medical Research Council of Australia.

Agreements, Behaviour, and Change: Sex Outside the Relationship in Male HIV-negative Partners in HIV Serodiscordant Relationships in Australia, Brazil, and Thailand.

Male HIV serodiscordant couples have diverse relationship agreements regarding sex outside the relationship. We examined the relationship agreements as described by 343 male HIV-negative partners in HIV serodiscordant relationships in Australia, Brazil and Thailand participating in a multi-year cohort study. At baseline, 125 (34.1%) HIV-negative partners reported no agreement, 115 (33.5%) had a monogamous agreement, and 103 (37.9%) had an open agreement allowing sex outside the relationship. Relationship agreements were largely stable over time, with 76% of HIV-negative men reporting the same agreement across follow up, while changes were predominantly towards having an open agreement. Behaviour largely matched relationship agreements, and the predictors of breaking an agreement by having condomless anal intercourse (CLAI) with an outside partner were CLAI within the relationship (OR = 3.17, 95%CI: 1.64-6.14, p < 0.001) and PrEP use in the last three months (OR = 3.42, 95%CI: 1.48-7.92, p = 0.004). When considering HIV transmission risk for HIV-negative men in serodiscordant relationships, greater focus needs to be placed on sex that is occurring outside the relationship and the agreements that facilitate this.

Attitudes Towards Treatment as Prevention Among PrEP-Experienced Gay and Bisexual Men in Australia.

The introduction of HIV pre-exposure prophylaxis (PrEP) has the potential to impact the attitudes gay and bisexual men (GBM) who consequently choose to take PrEP have towards treatment as prevention (TasP), and the extent to which they are willing to have condomless anal intercourse (CLAI) with an HIV-positive sexual partner who has an undetectable viral load (UVL). Using a cross-sectional sample from an observational cohort study conducted from August 2018 to March 2020, we examined the extent to which PrEP-experienced GBM are willing to have CLAI with a partner who has a UVL. Simple and multiple logistic regression models were used to identify associated variables. Of the 1386 participants included in the analyses, 79.0% believed in the effectiveness of TasP, and 55.3% were willing to have CLAI with a partner who has a UVL. Wiling participants were less worried about getting HIV when taking PrEP and more likely to believe in TasP. Further research is needed to better understand the gap between belief in TasP and willingness to have CLAI with a partner who has a UVL among PrEP-experienced GBM.

Factors Associated With Willingness to Use Daily Antibiotics as Sexually Transmitted Infection Prophylaxis Among HIV Preexposure Prophylaxis-Experienced Gay and Bisexual Men in Australia.

BACKGROUND: Gay and bisexual men (GBM) who use HIV preexposure prophylaxis (HIV-PrEP) have high rates of bacterial sexually transmitted infections (STIs). The use of daily antibiotics as STI preexposure prophylaxis (STI-PrEP) may be appealing to GBM who are using or have previously used HIV-PrEP (HIV-PrEP-experienced) for the prevention of bacterial STIs. METHODS: We examined willingness to use daily STI-PrEP among a cross-sectional sample of HIV-PrEP-experienced GBM in Australia who participated in an observational online cohort study from August 2018 to March 2020. Factors associated with willingness to use daily STI-PrEP were determined using bivariate and multivariate logistic regression. RESULTS: Of the 1347 participants, half (54.3%) were willing to use daily STI-PrEP. Factors independently associated with greater willingness to use daily STI-PrEP included having >10 sexual partners in the last 6 months, using methamphetamine in the last 6 months, being more conscious about avoiding STIs, having a greater number of STIs since commencing HIV-PrEP, being willing to take HIV-PrEP for as long as they were at risk of acquiring HIV, and only using condoms when a sexual partner requested them. Conversely, factors associated with less willingness to use daily STI-PrEP included being university educated, using nondaily dosing regimens of HIV-PrEP, preferring event-driven HIV-PrEP, and being concerned about long-term HIV-PrEP adverse effects. CONCLUSIONS: Sexually transmitted infection PrEP is likely to be appealing to many HIV-PrEP-experienced GBM, especially those who engage in activities associated with a higher risk of STI transmission. However, they are less likely to be willing to use STI-PrEP unless it aligns with their HIV-PrEP dosing regimen, suggesting that research into the safety and efficacy of alternative STI prophylaxis dosing options should be prioritized.

Second Primary Cancers in People With HIV/AIDS: A National Data Linkage Study of Incidence and Risk Factors.

BACKGROUND: Evidence regarding the characteristics of second primary cancer (SPC) in people living with HIV (PLWHIV) is limited. SETTING: We performed a national population-based data linkage study to determine the incidence and risk factors of SPC in PLWHIV in Australia between 1982 and 2012. METHODS: We conducted a probabilistic data linkage study to compare the incidence of SPC over time, defined using HIV treatment eras, for SPCs related to oncogenic viral infection in comparison with non-infection-related SPCs. Risk factors considered included age at diagnosis of cancer, sex, HIV exposure modality, and CD4 + count. RESULTS: Of 29,383 individuals diagnosed with HIV, 3123 individuals who developed a first primary cancer were included in the analysis. Among them, 229 cases of SPC were identified across 27,398 person-years of follow-up. The most common SPCs were non-Hodgkin lymphomas (n = 71, 31%). The incidence of SPC overall did not change over time; however, there was an increase in individuals diagnosed with HIV in later eras ( P trend =0.001). The incidence of non-infection-related SPC increased over time and was associated with older age ( P trend = 0.005) and the acquisition of HIV in later eras ( P trend <0.001). Conversely, the incidence of infection-related SPC decreased ( P trend <0.001), but this was no longer significant after adjustment for age ( P trend = 0.14). CONCLUSIONS: The risk of SPC in PLWHIV in Australia remains high, with a temporal increase observed in non-infection-related cancer, likely due to aging of the population. Optimal screening and prevention strategies for SPC in PLWHIV are increasingly important.

Cost-effectiveness of screening and treating anal pre-cancerous lesions among gay, bisexual and other men who have sex with men living with HIV.

Background: Gay, bisexual and other men who have sex with men (GBM) living with HIV have a substantially elevated risk of anal cancer (85 cases per 100,000 person-years vs 1-2 cases per 100,000 person-years in the general population). The precursor to anal cancer is high-grade squamous intraepithelial lesion (HSIL). Findings regarding the cost-effectiveness of HSIL screening and treatment in GBM are conflicting. Using recent data on HSIL natural history and treatment effectiveness, we aimed to improve upon earlier models. Methods: We developed a Markov cohort model populated using observational study data and published literature. Our study population was GBM living with HIV aged ≥35 years. We used a lifetime horizon and framed our model on the Australian healthcare perspective. The intervention was anal HSIL screening and treatment. Our primary outcome was the incremental cost-effectiveness ratio (ICER) as cost per quality-adjusted life-year (QALY) gained. Findings: Anal cancer incidence was estimated to decline by 44-70% following implementation of annual HSIL screening and treatment. However, for the most cost-effective screening method assessed, the ICER relative to current practice, Australian Dollar (AUD) 135,800 per QALY gained, remained higher than Australia's commonly accepted willingness-to-pay threshold of AUD 50,000 per QALY gained. In probabilistic sensitivity analyses, HSIL screening and treatment had a 20% probability of being cost-effective. When the sensitivity and specificity of HSIL screening were enhanced beyond the limits of current technology, without an increase in the cost of screening, ICERs improved but were still not cost-effective. Cost-effectiveness was achieved with a screening test that had 95% sensitivity, 95% specificity, and cost ≤ AUD 24 per test. Interpretation: Establishing highly sensitive and highly specific HSIL screening methods that cost less than currently available techniques remains a research priority. Funding: No specific funding was received for this analysis.

Renal impairment associated with tenofovir disoproxil fumarate for antiretroviral therapy and HIV pre-exposure prophylaxis: An observational cohort study.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) is associated with adverse renal outcomes when prescribed for HIV infection. There are few data concerning real-world renal outcomes amongst patients prescribed TDF for pre-exposure prophylaxis (PrEP). METHODS AND FINDINGS: Data were extracted from 52 sexual health clinics across Australia from 2009-2019. All patients prescribed TDF-containing antiretroviral therapy and PrEP were included. Rates of renal impairment (a fall in eGFR to <60 ml/min/1·73m2) were calculated for people living with HIV (PLWHIV) prescribed TDF and HIV negative PrEP-users. Risk factors were assessed using Cox-proportional hazards models. Sensitivity analysis of risk using 1:1 propensity-score matching to adjust for potential imbalance in HIV and PrEP cohorts was conducted. 5,973 patients on PrEP and 1,973 PLWHIV were included. There were 39 (0.7%) instances of renal impairment in the PrEP group and 81 (4.1%) in the PLWHIV cohort (hazard ratio [HR]:0.35 95% confidence interval [CI]: 0.22-0.56). Rates of renal impairment were 4.01/1000 person-years (95%CI:2.93-5.48) in the PrEP cohort and 16.18/1000 person-years (95%CI:13.01-20.11) in the PLWHIV cohort (p<0.001). Predictors of renal impairment were: older age (40-49 years (HR:5.09 95%CI: 2.12-12.17) and 50-82 years (HR:13.69 95%CI: 5.92-31.67) (compared with 30-39 years) and baseline eGFR<90ml/min (HR:61.19 95%CI: 19.27-194.30). After adjusting for age and baseline eGFR the rate of renal impairment remained lower in the PrEP cohort (aHR:0.62 95%CI: 0.40-0.94, p = 0.023). In propensity-matched analysis using 1,622 patients per cohort the risk of renal impairment remained higher in the PLWHIV cohort (log-rank p = 0.001). CONCLUSION: Patients prescribed TDF-based PrEP had lower rates of renal impairment than patients prescribed TDF for HIV infection. In propensity analysis, after matching for some risk factors, rates of renal impairment remained higher amongst patients with HIV.

Identifying Patterns of Discontinuing and Recommencing Pre-exposure Prophylaxis in the Context of Sexual Behavior Among Gay and Bisexual Men in Australia.

We mapped gay and bisexual men's (GBM) patterns of using pre-exposure prophylaxis (PrEP) over time and explored sexual behavior as PrEP use changed. We conducted semi-structured interviews between June 2020 and February 2021 with 40 GBM living in Australia who had changed their PrEP use since initiating. There was considerable diversity in patterns of discontinuation, suspension, and recommencement of PrEP. Reasons for changing PrEP use mostly centered on accurate perceived changes to HIV risk. Twelve participants reported condomless anal intercourse with casual or fuckbuddy partners after discontinuing PrEP. These sex events were unanticipated, condoms were not a preferred option, and other risk reduction strategies were applied inconsistently. Service delivery and health promotion can support safer sex among GBM when PrEP use fluctuates by promoting event-driven PrEP and/or non-condom-based risk reduction methods during periods off daily PrEP, and guiding GBM to better recognize changing circumstances of risk and when to recommence PrEP.

Performance of Human Papillomavirus Attribution Algorithms to Predict Causative Genotypes in Anal High-Grade Lesions.

BACKGROUND: Gay and bisexual men (GBM) are at increased risk of human papillomavirus (HPV)-associated anal high-grade squamous intraepithelial lesions (HSILs). Understanding the fractions of HSILs attributable to HPV genotypes is important to inform potential impacts of screening and vaccination strategies. However, multiple infections are common, making attribution of causative types difficult. Algorithms developed for predicting HSIL-causative genotype fractions have never been compared with a reference standard in GBM. METHOD: Samples were from the Study of the Prevention of Anal Cancer. Baseline HPV genotypes detected in anal swab samples (160 participants) were compared with HPV genotypes in anal HSILs (222 lesions) determined by laser capture microdissection (LCM). Five algorithms were compared: proportional, hierarchical, maximum, minimum, and maximum likelihood estimation. RESULTS: All algorithms predicted HPV-16 as the most common HSIL-causative genotype, and proportions differed from LCM detection (37.8%) by algorithm (with differences of -6.1%, +20.9%, -20.4%, +2.9%, and +2.2% respectively). Fractions predicted using the proportional method showed a strong positive correlation with LCM, overall (R = 0.73 and P = .002), and by human immunodeficiency virus (HIV) status (HIV positive, R = 0.74 and P = .001; HIV-negative, R = 0.68 and P = .005). CONCLUSIONS: Algorithms produced a range of inaccurate estimates of HSIL attribution, with the proportional algorithm performing best. The high occurrence of multiple HPV infections means that these algorithms may be of limited use in GBM.

Discontinuation of government subsidized HIV pre-exposure prophylaxis in Australia: a whole-of-population analysis of dispensing records.

INTRODUCTION: HIV pre-exposure prophylaxis (PrEP) has been government subsidized in Australia since April 2018 and while uptake is high among men who have sex with men, rates of discontinuation are also high. The aims of this study were to examine the impact of discontinuation on overall PrEP usage, the proportion of PrEP users who discontinue and the predictors of discontinuation. METHODS: We used linked de-identified dispensing records of all government subsidized PrEP in Australia between April 2018 and September 2021: a whole-of-population data set. Defining discontinuation as 180 days or more without PrEP after the final dispensed supply, we calculated the number of people who discontinued at each 6-month interval during the study period, the proportion who had discontinued 2 years after the first supply and, using Cox regression, predictors of discontinuation. RESULTS: Of 49,164 people dispensed PrEP (98.5% male, median age 34 years), 40.3% (19,815) had discontinued by September 2021. Within 2 years of their first supply, 11,150 (37.7%) of 29,549 PrEP users had discontinued, including 10.0% after a single dispensed supply. Large variations were observed, particularly according to prescriber characteristics: discontinuation was higher among people prescribed PrEP by low caseload (≤10 patients) prescribers (61.2%) than by high caseload (>100 patients) prescribers (31.1%, p<0.001), and by prescribers practising in areas with low estimated prevalence (<1.0%) of gay men (64.1%) than high (>5%) prevalence (36.7%, p<0.001). Women and younger people were more likely to discontinue, while patients receiving a higher level of government subsidy were less likely. The independent predictors of discontinuation with the greatest effect size were female sex (adjusted hazards ratio [aHR] 2.99, p<0.001), low estimated gay prevalence of prescriber location (aHR 1.98, p<0.001) and low prescriber PrEP caseload (aHR 1.79, p<0.001). CONCLUSIONS: There are high rates of PrEP discontinuation in Australia and some populations are at increased risk of discontinuation. Strategies are needed to support persistence on PrEP and the re-starting of PrEP during periods of risk.

How to have sex in a pandemic: the development of strategies to prevent COVID-19 transmission in sexual encounters among gay and bisexual men in Australia.

Although many studies reported on decreases in sexual partner numbers among gay and bisexual-identifying men in the early period of the COVID-19 pandemic, few studies have explored COVID-19 risk-reduction strategies. Drawing on free-text responses in an online survey (from April to July 2020), we describe the ways in which men sought to minimise the risk of COVID-19 in sexual encounters. Partner selection was an important strategy, in particular, restricting sex to men they already knew. Accounts also indicate how participants assessed risk from potential sex partners based on symptoms, residential location, recent travel, work role, and number of other sexual contacts. Less common were in situ practices, such as avoiding kissing. Participants' responses provide insight into creative community-based responses in the early months of the pandemic, some of which have resonances with early responses to HIV. Findings are discussed in relation to the concepts of 'lay epidemiology' and 'counterpublic health'. In particular, we examine how risks and health are experienced and valued in relation to local knowledges, meanings, and practices; and how practices emerge in response to dominant public health discourses that produce an idealised public based on (hetero)normative assumptions.