Characterising HIV-1 transmission in Victoria, Australia: a molecular epidemiological study.

Background: In Australia the incidence of HIV has declined steadily, yet sustained reduction of HIV transmission in this setting requires improved public health responses. As enhanced public health responses and prioritisation of resources may be guided by molecular epidemiological data, here we aimed to assess the applicability of these approaches in Victoria, Australia. Methods: A comprehensive collection of HIV-1 pol sequences from individuals diagnosed with HIV in Victoria, Australia, between January 1st 2000 and December 31st 2020 were deidentified and used as the basis of our assessment. These sequences were subtyped and surveillance drug resistance mutations (SDRMs) identified, before definition of transmission groups was performed using HIV-TRACE (0.4.4). Phylodynamic methods were applied using BEAST (2.6.6), assessing effective reproductive numbers for large groups, and additional demographic data were integrated to provide a high resolution view of HIV transmission in Victoria on a decadal time scale. Findings: Based on standard settings for HIV-TRACE, 70% (2438/3507) of analysed HIV-1 pol sequences were readily assigned to a transmission group. Individuals in transmission groups were more commonly males (aOR 1.50), those born in Australia (aOR 2.13), those with probable place of acquisition as Victoria (aOR 6.73), and/or those reporting injectable drug use (aOR 2.13). SDRMs were identified in 375 patients (10.7%), with sustained transmission of these limited to a subset of smaller groups. Informative patterns of epidemic growth, stabilisation, and decline were observed; many transmission groups showed effective reproductive numbers (R e ) values reaching greater than 4.0, representing considerable epidemic growth, while others maintained low R e values. Interpretation: This study provides a high resolution view of HIV transmission in Victoria, Australia, and highlights the potential of molecular epidemiology to guide and enhance public health responses in this setting. This informs ongoing discussions with community groups on the acceptability and place of molecular epidemiological approaches in Australia. Funding: National Health and Medical Research Council, Australian Research Council.

Validation of self-reported human papillomavirus vaccination in young adult men who have sex with men.

The Victorian Government introduced a time-limited human papillomavirus (HPV) catch-up program for gay, bisexual, and other men who have sex with men (GBMSM) aged ≤ 26 years in 2017-2019. We conducted a retrospective observational study to examine the accuracy of the self-report of HPV vaccination status using computer-assisted self-interviewing versus their immunization history via electronic health records. We included GBMSM aged 23-30 years visiting the Melbourne Sexual Health Centre (MSHC) in 2020-2021 because they were age-eligible for the HPV catch-up program in Victoria, Australia. Individuals who were unsure about their vaccination status were categorized as 'unvaccinated'. Of the 1,786 eligible men, 1,665 men self-reported their HPV vaccination status: 48.8% (n = 812) vaccinated, 17.4% (n = 289) unvaccinated, and 33.9% (n = 564) unsure. Self-reported HPV vaccination had a sensitivity of 61.3% (95%CI: 58.3 to 64.2%; 661/1079), a specificity of 74.2% (95%CI: 70.5 to 77.7%; 435/586), a positive predictive value of 81.4% (95%CI: 78.6 to 84.0%; 661/812), a negative predictive value of 51.0% (95%CI: 47.6 to 54.4%; 435/853), and an accuracy of 52.6% (95%CI: 50.1 to 55.0%). Our results showed that only half of GBMSM know and report their HPV vaccination status correctly. Novel approaches such as digital vaccine passports may be useful for individuals to accurately report their vaccination status to guide accurate clinical decisions and management.

Evaluation of artificial intelligence-powered screening for sexually transmitted infections-related skin lesions using clinical images and metadata.

BACKGROUND: Sexually transmitted infections (STIs) pose a significant global public health challenge. Early diagnosis and treatment reduce STI transmission, but rely on recognising symptoms and care-seeking behaviour of the individual. Digital health software that distinguishes STI skin conditions could improve health-seeking behaviour. We developed and evaluated a deep learning model to differentiate STIs from non-STIs based on clinical images and symptoms. METHODS: We used 4913 clinical images of genital lesions and metadata from the Melbourne Sexual Health Centre collected during 2010-2023. We developed two binary classification models to distinguish STIs from non-STIs: (1) a convolutional neural network (CNN) using images only and (2) an integrated model combining both CNN and fully connected neural network (FCN) using images and metadata. We evaluated the model performance by the area under the ROC curve (AUC) and assessed metadata contributions to the Image-only model. RESULTS: Our study included 1583 STI and 3330 non-STI images. Common STI diagnoses were syphilis (34.6%), genital warts (24.5%) and herpes (19.4%), while most non-STIs (80.3%) were conditions such as dermatitis, lichen sclerosis and balanitis. In both STI and non-STI groups, the most frequently observed groups were 25-34 years (48.6% and 38.2%, respectively) and heterosexual males (60.3% and 45.9%, respectively). The Image-only model showed a reasonable performance with an AUC of 0.859 (SD 0.013). The Image + Metadata model achieved a significantly higher AUC of 0.893 (SD 0.018) compared to the Image-only model (p < 0.01). Out of 21 metadata, the integration of demographic and dermatological metadata led to the most significant improvement in model performance, increasing AUC by 6.7% compared to the baseline Image-only model. CONCLUSIONS: The Image + Metadata model outperformed the Image-only model in distinguishing STIs from other skin conditions. Using it as a screening tool in a clinical setting may require further development and evaluation with larger datasets.

A typology of HIV self-testing support systems: a scoping review.

To maximise the benefits of HIV self-testing (HIVST), it is critical to support self-testers in the testing process and ensure that they access appropriate prevention and care. To summarise systems and tools supporting HIVST (hereafter, 'support systems') and categorise them for future analysis, we synthesised the global data on HIVST support systems and proposed a typology. We searched five databases for articles reporting on one or more HIVST support systems and included 314 publications from 224 studies. Across 189 studies, there were 539 reports of systems supporting HIVST use; while across 115 studies, there were 171 reports of systems supporting result interpretation. Most commonly, these were pictorial instructions, followed by in-person demonstrations and in-person assistance while self-testing or reading self-test results. Less commonly, virtual interventions were also identified, including online video conferencing and smartphone apps. Smartphone-based automated result readers have been used in the USA, China, and South Africa. Across 173 studies, there were 987 reports of systems supporting post-test linkage to care; most commonly, these were in-person referrals/counselling, written referrals, and phone helplines. In the USA, Bluetooth beacons have been trialled to monitor self-test use and facilitate follow-up. We found that, globally, HIVST support systems use a range of methods, including static media, virtual tools, and in-person engagement. In-person and printed approaches were more common than virtual tools. Other considerations, such as linguistic and cultural appropriateness, may also be important in the development of effective HIVST programs.

Annual hepatitis C testing and positive tests among gay and bisexual men in Australia from 2016 to 2022: a serial cross-sectional analysis of sentinel surveillance data.

OBJECTIVE: Guidelines recommend annual hepatitis C virus (HCV) testing for gay and bisexual men (GBM) with HIV and GBM prescribed HIV pre-exposure prophylaxis (PrEP). However, there is a limited understanding of HCV testing among GBM. We aimed to examine trends in HCV testing and positivity from 2016 to 2022. METHODS: Using sentinel surveillance data, we examined the proportion of GBM with at least one test and the proportion with a positive test in each year for HCV antibody testing among GBM with no previous HCV positive test, HCV RNA testing among GBM with a positive antibody test but no previous positive RNA test (naïve RNA testing), and HCV RNA testing among people who had a previous RNA positive test and a subsequent negative test (RNA follow-up testing). Trends were examined using logistic regression from 2016 to 2019 and 2020 to 2022. RESULTS: Among GBM with HIV, from 2016 to 2019 antibody testing was stable averaging 55% tested annually. Declines were observed for both naïve HCV RNA testing (75.4%-41.4%: p<0.001) and follow-up HCV RNA testing (70.1%-44.5%: p<0.001). Test positivity declined for HCV antibody tests (2.0%-1.3%: p=0.001), HCV RNA naïve tests (75.4%-41.4%: p<0.001) and HCV RNA follow-up tests (11.3%-3.3%: p=0.001). There were minimal or no significant trends from 2020 to 2022.Among GBM prescribed PrEP, antibody testing declined from 2016 to 2019 (79.4%-69.4%: p<0.001) and was stable from 2020 to 2022. Naïve and follow-up HCV RNA testing was stable with an average of 55% and 60% tested each year, respectively. From 2016-2019, the proportion positive from HCV RNA naïve tests declined (44.1%-27.5%: p<0.046) with no significant change thereafter. Positive follow-up HCV RNA tests fluctuated with no or one new positive test among this group in most years. CONCLUSION: The proportion of GBM with positive HCV tests has declined, however a substantial proportion are not tested annually. A renewed focus on HCV testing, and treatment where required, is warranted to achieve HCV elimination among GBM in Australia.

Cost-effectiveness of resistance-guided therapy for Mycoplasma genitalium in Australia.

The recommended first-line treatment for Mycoplasma genitalium infections is azithromycin. However, the prevalence of macrolide resistance for M. genitalium has increased to more than 50% worldwide. In 2013, Australia introduced a resistance-guided therapy (RGT) strategy to manage M. genitalium infections. This study assesses the cost-effectiveness of the RGT approach compared to no RGT (i.e., without macrolide resistance profile test) in women, men who have sex with men (MSM), and men who have sex with women (MSW) in Australia. We constructed dynamic transmission models of M. genitalium infections in women, MSM, and MSW in Australia, each with a population of 100,000. These models compared the costs and quality-adjusted life-years (QALYs) gained between RGT and no RGT scenarios from a healthcare perspective over ten years. All costs are reported in 2022 Australian dollars (Australian $). In our model, RGT is cost saving in women and MSM, with the incremental net monetary benefit of $1.3 million and $17.9 million, respectively. In MSW, the RGT approach is not cost-effective, with an incremental cost-effectiveness ratio of -$106.96 per QALY gained. RGT is cost saving compared to no RGT for M. genitalium infections in women and MSM, supporting its adoption as the national management strategy for these two population groups.

Vaginal anaerobes are associated with cervicitis: A case-control study.

OBJECTIVES: Cervicitis is associated with important reproductive sequelae. Primary causes include chlamydia and gonorrhoea, but a known sexually transmitted infection (STI) is not identified in >50% of cases (i.e. STI-negative cervicitis). Bacterial vaginosis (BV) and specific BV-associated bacteria have also been associated with cervicitis, but data are limited. We investigated the association between STI-negative cervicitis and vaginal microbiota composition. METHODS: This was a case-control sub-study of the OhMG study conducted at the Melbourne Sexual Health Centre. Cases were women with cervicitis who tested negative for STIs (STI-negative cervicitis, n = 64). Controls were STI-negative asymptomatic women attending for STI-screening (n = 128). The vaginal microbiota was characterised using 16S rRNA gene sequencing. Vaginal community state types were compared between cases and controls using logistic regression. Differential abundance analysis was performed to identify taxa associated with STI-negative cervicitis. RESULTS: STI-negative cervicitis cases were more likely than controls to have a Lactobacillus-deficient non-optimal microbiota (adjusted-odds-ratio 2.55, 95% CI 1.18-5.50). Compared to controls, cases had increased abundance of four BV-associated bacteria (Gardnerella, Fannyhessea vaginae, Prevotella bivia, Dialister micraerophilus) and decreased abundance of optimal lactobacilli. CONCLUSIONS: We report a positive association between non-optimal vaginal microbiota composition and STI-negative cervicitis. Specific anaerobic BV-associated bacteria may represent infectious causes of cervicitis.

Economic evaluation alongside a clinical trial of near-to-patient testing for sexually transmitted infections.

BACKGROUND: Current clinical care for common bacterial STIs (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG)) involves empiric antimicrobial therapy when clients are symptomatic, or if asymptomatic, waiting for laboratory testing and recall if indicated. Near-to-patient testing (NPT) can improve pathogen-specific prescribing and reduce unnecessary or inappropriate antibiotic use in treating sexually transmitted infections (STI) by providing same-day delivery of results and treatment. METHODS: We compared the economic cost of NPT to current clinic practice for managing clients with suspected proctitis, non-gonococcal urethritis (NGU), or as an STI contact, from a health provider's perspective. With a microsimulation of 1000 clients, we calculated the cost per client tested and per STI- and pathogen- detected for each testing strategy. Sensitivity analyses were conducted to assess the robustness of the main outcomes. Costs are reported as Australian dollars (2023). RESULTS: In the standard care arm, cost per client tested for proctitis, NGU in men who have sex with men (MSM) and heterosexual men were the highest at $247.96 (95% Prediction Interval (PI): 246.77-249.15), $204.23 (95% PI: 202.70-205.75) and $195.01 (95% PI: 193.81-196.21) respectively. Comparatively, in the NPT arm, it costs $162.36 (95% PI: 161.43-163.28), $158.39 (95% PI: 157.62-159.15) and $149.17 (95% PI: 148.62-149.73), respectively. Using NPT resulted in cost savings of 34.52%, 22.45% and 23.51%, respectively. Among all the testing strategies, substantial difference in cost per client tested between the standard care arm and the NPT arm was observed for contacts of CT or NG, varying from 27.37% to 35.28%. CONCLUSION: We found that NPT is cost-saving compared with standard clinical care for individuals with STI symptoms and sexual contacts of CT, NG, and MG.

Prevalence of cefixime-resistant Neisseria gonorrhoeae in Melbourne, Australia, 2021-2022.

While ceftriaxone remains the first-line treatment for gonorrhoea, the US CDC recommended cefixime as a second-line treatment in 2021. We tested 1176 Neisseria gonorrhoeae isolates among clients attending the Melbourne Sexual Health Centre in 2021-2022. The prevalence of cefixime resistance was 6.3% (74/1176), azithromycin resistance was 4.9% (58/1176) and ceftriaxone resistance was 0% (0/1176). Cefixime resistance was the highest among women (16.4%, 10/61), followed by men-who-have-sex-with-women (6.4%, 7/109), and men-who-have-sex-with-men (5.8%, 57/982). The prevalence of cefixime-resistant N. gonorrhoeae exceeds the threshold of the 5% resistance level recommended by the World Health Organization; and thus, cefixime treatment would have limited benefits in Australia.

Factors Associated With Recent Decline in Anal Health Among Older Gay and Bisexual Men: A Cross-sectional Analysis.

ABSTRACT: We investigated factors associated with "worse than usual" anal health among gay and bisexual men aged ≥35 years recruited to a longitudinal study of anal human papillomavirus infection/lesions from September 2010 to August 2015.Among 616 participants (median age 49 years; 36% HIV-positive), 42 (6.8%) reported worse than usual anal health in the last 4 weeks. Associated factors included spending less time with gay friends (odds ratio [OR] = 2.25, 95% CI = 1.06-4.77), most time "feeling down"(OR = 9.17, 95% CI = 2.94-28.59), reduced libido (OR = 2.90, 95% CI = 1.52-5.52), current anal symptoms (OR = 6.55, 95% CI = 2.54-16.90), recent anal wart diagnosis (OR = 4.33, 95% CI = 1.98-9.49), and fear of developing anal cancer (OR = 9.34, 95% CI = 4.52-19.28).Concerns regarding anal health should be routinely discussed by clinicians, and potentially associated psychosocial, physical, and sexual issues further explored.

Understanding Risk Factors for Oropharyngeal Gonorrhea Among Sex Workers Attending Sexual Health Clinics in 2 Australian Cities: Mixed Methods Study.

BACKGROUND: The risk factors for oropharyngeal gonorrhea have not been examined in sex workers despite the increasing prevalence of gonorrhea infection. OBJECTIVE: This study aims to determine the risk factors for oropharyngeal gonorrhea in female and gender-diverse sex workers (including cisgender and transgender women, nonbinary and gender fluid sex workers, and those with a different identity) and examine kissing, oral sex, and mouthwash practices with clients. METHODS: This mixed methods case-control study was conducted from 2018 to 2020 at 2 sexual health clinics in Melbourne, Victoria, and Sydney, New South Wales, Australia. We recruited 83 sex workers diagnosed with oropharyngeal gonorrhea (cases) and 581 sex workers without (controls). Semistructured interviews with 19 sex workers from Melbourne were conducted. RESULTS: In the case-control study, the median age of 664 sex workers was 30 (IQR 25-36) years. Almost 30% of sex workers (192/664, 28.9%) reported performing condomless fellatio on clients. Performing condomless fellatio with clients was the only behavior associated with oropharyngeal gonorrhea (adjusted odds ratio 3.6, 95% CI 1.7-7.6; P=.001). Most participants (521/664, 78.5%) used mouthwash frequently. In the qualitative study, almost all sex workers reported kissing clients due to demand and generally reported following clients' lead with regard to kissing style and duration. However, they used condoms for fellatio because they considered it a risky practice for contracting sexually transmitted infections, unlike cunnilingus without a dental dam. CONCLUSIONS: Our study shows that condomless fellatio is a risk factor for oropharyngeal gonorrhea among sex workers despite most sex workers using condoms with their clients for fellatio. Novel interventions, particularly targeting the oropharynx, will be required for oropharyngeal gonorrhea prevention.

Restarting pre-exposure prophylaxis (PrEP) for HIV: a systematic review and meta-analysis.

Background: High coverage of pre-exposure prophylaxis (PrEP) will reduce HIV transmission and help end the HIV/AIDS pandemic. However, PrEP users face challenges, including long-term adherence. The study aimed to document the proportions of individuals who restart HIV PrEP after they stop and the reasons for restarting PrEP. Methods: This study is a systematic review and meta-analysis. We systematically searched CINAHL, Embase, Emcare, Global Health, Medline, Scopus, and PsychINFO for peer-reviewed with no date restrictions. A grey literature search was conducted through Google search, a search of abstract books of AIDS conferences and the websites of WHO and UNAIDS. The data search was conducted in April 2023 and updated in February 2024. Two authors extracted data on the proportion of people who stopped and then restarted PrEP, reasons for restarting, and strategies to support people restarting PrEP. Two authors appraised the data using the Joanna Briggs Institute Appraisal Tools. We used a random-effects meta-analysis to pool estimates of restarting. We conducted meta-regression to determine potential sources of heterogeneity. This study is registered with PROSPERO, CRD42023416777. However, we deviated from our original plan as we did not identify enough studies for strategies to support restarting PrEP (primary objective). Subsequently, we revised our plan to strengthen our secondary objective to quantify the proportion of people who stopped and restarted PrEP, and explore possible reasons for its heterogeneity. Findings: Of 988 studies, 30 unique studieswere included: 27 reported the proportion restarting PrEP, and of these, 7 also reported reasons for restarting PrEP, and 3 studies reported only on the reasons for restarting PrEP. No study evaluated interventions for restarting PrEP. For the meta-analysis, we included 27 studies. Most studies were from high-income countries (17/27, 63%) or the USA (15/27, 56%). Overall, 23.8% (95% CI: 15.9-32.7, I2 = 99.8%, N = 85,683) of people who stopped PrEP restarted PrEP. There was a lower proportion of restarting in studies from middle-income countries compared to high-income countries (adjusted odds ratio (aOR) 0.6, 95% CI: 0.50-0.73, p < 0.001). There was higher restarting in studies from Africa compared to the USA (aOR 1.55, 95% CI: 1.30-1.86), heterosexual populations compared to men who have sex with men or transgender women (aOR 1.50, 95% CI: 1.25-1.81, p < 0.001) and in studies defining restarting as those who had stopped PrEP for >1 month compared to those who stopped <1 month (aOR 1.20, 95% CI: 1.06-1.36, p < 0.001). Reasons for restarting PrEP included perceived higher risk for HIV acquisition and removal of barriers to access PrEP. In terms of quality assessment, overall, both randomised controlled trials had a low risk of bias, while the observational studies used in the meta-analysis had some potential risk of bias related to not explicitly addressing potential confounders (15/25, 60%) or not describing strategies to address incomplete follow-up (24/25, 96%). Interpretation: About a quarter of people who stopped PrEP would restart, with substantial variation across countries and populations. It is important to understand the motivations and contextual factors influencing restarting PrEP and the support systems to enable restarting PrEP for those at ongoing risk. Funding: Australian National Health and Medical Research Council.

Management of acute sexual assault presenting to a large Australian sexual health clinic in 2012-2021: a retrospective clinical audit.

Background The incidence of sexual assault continues to rise in Australia. This study aimed to describe the nature of assault, HIV/STI positivity, and its management at a sexual health clinic. Methods We performed a chart review of 516 sexual assault cases presenting to Melbourne Sexual Health Centre between 2012 and 2021, collecting data on victim demographics, details of assault, HIV/STI testing and positivity, police involvement, and offer of counselling. Results We included 516 cases: 124 males (24.0%); 384 females (74.4%); and eight transgender (1.6%) victims. The proportion of assault cases presenting to Melbourne Sexual Health Centre increased from 0.1% (37/37,070) in 2012 to 0.2% (56/36,514) in 2021 (P trend =0.006). HIV post-exposure prophylaxis was prescribed for 64.5% (80/124) of males and 12.5% (48/384) of females. Among victims, 69.4% (358/516) were tested for HIV and no one tested positive, while 71.9% (371/516) were tested for syphilis, with 1.6% (6/371) positive. Gonorrhoea and chlamydia were tested at the oropharynx (44.8% [231/516] vs 28.7% [148/516]), genitals (83.7% [432/516] vs 92.4% [477/516]) and anorectum (35.3% [182/516] vs 35.3% [182/516]). Positivity for gonorrhoea and chlamydia were: 2.6% (6/231) vs 2.0% (3/148) at oropharynx, 1.4% (6/432) vs 2.9% (14/477) at genitals, and 5.5% (10/182) vs 7.1% (13/182) at anorectum. According to clinical records, 25.2% (130/516) of victims sought police involvement, and 71.7% (370/516) were offered counselling. Conclusions Sexual assault was an uncommon presentation at Melbourne Sexual Health Centre, with diverse circumstances surrounding assault; however, clinical documentation varied, indicating a need for a standard primary care protocol for clients presenting with acute sexual assault.

Factors associated with HIV pre-exposure prophylaxis use among Asian men who have sex with men in Sydney and Melbourne, Australia: a cross-sectional study.

Background: Asian-born MSM are a priority population as Australia aims to end HIV transmission, but they reported additional barriers to access PrEP and other HIV prevention methods. This study investigates factors associated with PrEP use among Asian MSM in Sydney and Melbourne, Australia, to inform strategies to improve PrEP uptake in this population. Methods: This was a sub-analysis of a community-based cross-sectional survey conducted from March to June 2021. We recruited participants online in Sydney and Melbourne, Australia. Univariable and multivariable logistic regression analyses were performed to identify the factors associated with PrEP use in the last six months and lifetime. Latent class analyses were used to identify subgroups of Asian MSM sharing similar characteristics related to their risk practices for HIV. Findings: Overall, 870 Asian MSM were included: 288 Oceanian-born Asian MSM and 582 Asian-born MSM. Three latent classes were identified: 1) Asian-born MSM who recently arrived in Australia with limited English, were less likely to use PrEP and at higher risk of HIV infection (e.g., had condomless anal sex with a casual sex partner in the last six months) (4.6%); 2) Asian MSM who were at lower risk of HIV infection and less likely to use PrEP (69.3%) and; 3) Asian MSM who were at substantial risk of HIV infection and more likely to use PrEP (26.1%). Compared to Oceanian-born Asian MSM, those who were born in Southeast Asia (adjusted odds ratio (aOR) = 0.5, 95% confidence interval (CI) 0.3-0.7) and South Asia (aOR = 0.4, 95% CI 0.2-0.8) were less likely to ever use PrEP. Compared to Oceanian-born Asian MSM, those who were born in Southeast Asia (aOR = 0.4, 95% CI 0.3-0.7), Northeast Asia (aOR = 0.5, 95% CI 0.3-0.8) and South Asia (aOR = 0.4, 95% CI 0.2-0.7) were less likely to use PrEP in the last six months. Interpretation: To end HIV transmission in Australia, it will be necessary to develop strategies to improve PrEP access for the significant minority of Asian-born MSM who are at substantial risk of HIV infection. Funding: EPFC and JJO are supported by an Australian National Health and Medical Research Council (NHMRC) Emerging Leadership Investigator Grant (EPFC: GNT1172873 and JJO: GNT1193955). CKF is supported by an Australian National Health and Medical Research Council (NHMRC) Leadership Investigator Grant (GNT1172900).

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.

Risk of Primary Incident Hepatitis C Infection Following Bacterial Sexually Transmissible Infections Among Gay and Bisexual Men in Australia From 2016 to 2020.

Background: In Australia, the incidence of hepatitis C virus (HCV) has declined among gay and bisexual men (GBM) with human immunodeficiency virus (HIV) since 2015 and is low among GBM using HIV preexposure prophylaxis (PrEP). However, ongoing HCV testing and treatment remains necessary to sustain this. To assess the potential utility of sexually transmissible infections (STIs) to inform HCV testing among GBM with HIV and GBM using PrEP, we examined the association between bacterial STI diagnoses and subsequent primary HCV infection. Methods: Data were from a national network of 46 clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance. GBM included had ≥1 HCV antibody negative test result and ≥1 subsequent HCV antibody and/or RNA test. Discrete time survival analysis was used to estimate the association between a positive syphilis, rectal chlamydia, and rectal gonorrhea diagnosis in the previous 2 years and a primary HCV diagnosis, defined as a positive HCV antibody or RNA test result. Results: Among 6529 GBM with HIV, 92 (1.4%) had an incident HCV infection. A prior positive syphilis diagnosis was associated with an incident HCV diagnosis (adjusted hazard ratio, 1.99 [95% confidence interval, 1.11-3.58]). Among 13 061 GBM prescribed PrEP, 48 (0.4%) had an incident HCV diagnosis. Prior rectal chlamydia (adjusted hazard ratio, 2.75 [95% confidence interval, 1.42-5.32]) and rectal gonorrhea (2.54 [1.28-5.05]) diagnoses were associated with incident HCV. Conclusions: Diagnoses of bacterial STIs in the past 2 years was associated with HCV incidence. These findings suggest that STIs might be useful for informing HCV testing decisions and guidelines for GBM with HIV and GBM using PrEP.

Identifying Individuals at High Risk for HIV and Sexually Transmitted Infections With an Artificial Intelligence-Based Risk Assessment Tool.

Background: We have previously developed an artificial intelligence-based risk assessment tool to identify the individual risk of HIV and sexually transmitted infections (STIs) in a sexual health clinical setting. Based on this tool, this study aims to determine the optimal risk score thresholds to identify individuals at high risk for HIV/STIs. Methods: Using 2008-2022 data from 216 252 HIV, 227 995 syphilis, 262 599 gonorrhea, and 320 355 chlamydia consultations at a sexual health center, we applied MySTIRisk machine learning models to estimate infection risk scores. Optimal cutoffs for determining high-risk individuals were determined using Youden's index. Results: The HIV risk score cutoff for high risk was 0.56, with 86.0% sensitivity (95% CI, 82.9%-88.7%) and 65.6% specificity (95% CI, 65.4%-65.8%). Thirty-five percent of participants were classified as high risk, which accounted for 86% of HIV cases. The corresponding cutoffs were 0.49 for syphilis (sensitivity, 77.6%; 95% CI, 76.2%-78.9%; specificity, 78.1%; 95% CI, 77.9%-78.3%), 0.52 for gonorrhea (sensitivity, 78.3%; 95% CI, 77.6%-78.9%; specificity, 71.9%; 95% CI, 71.7%-72.0%), and 0.47 for chlamydia (sensitivity, 68.8%; 95% CI, 68.3%-69.4%; specificity, 63.7%; 95% CI, 63.5%-63.8%). High-risk groups identified using these thresholds accounted for 78% of syphilis, 78% of gonorrhea, and 69% of chlamydia cases. The odds of positivity were significantly higher in the high-risk group than otherwise across all infections: 11.4 (95% CI, 9.3-14.8) times for HIV, 12.3 (95% CI, 11.4-13.3) for syphilis, 9.2 (95% CI, 8.8-9.6) for gonorrhea, and 3.9 (95% CI, 3.8-4.0) for chlamydia. Conclusions: Risk scores generated by the AI-based risk assessment tool MySTIRisk, together with Youden's index, are effective in determining high-risk subgroups for HIV/STIs. The thresholds can aid targeted HIV/STI screening and prevention.

Optimizing health resource allocation for improving timely HIV diagnosis in China.

INTRODUCTION: The Joint United Nations Programme on HIV/AIDS (UNAIDS) updated the 95-95-95 targets for the HIV endgame in 2030. To achieve the first target in a timely manner, we investigate the optimized strategy of resource allocation to maximize timely HIV diagnosis in 14 populations in China. METHODS: We developed a mathematical model by integrating epidemiological, demographical and behavioural data from 12 high-risk and two general populations to evaluate the impact of various resource allocation strategies of HIV testing on HIV incidence in China. We identified the optimized allocation strategy that maximizes the number of HIV diagnoses at an estimated total spending on HIV tests in China and calculated the per-capita cost of new HIV case detection. RESULTS: We estimated that 144,795 new HIV cases may occur annually in 14 populations in China, with a total annual spending of US$2.8 billion on HIV testing. The largest proportion of spending was allocated to general males (44.0%), followed by general females (42.6%) and pregnant women (5.1%). Despite this allocation strategy, only 45.5% (65,867/144,795, timely diagnosis rate) of annual new infections were diagnosed within a year of acquisition, with a cost of $42,852 required for each new HIV case detection. By optimizing the allocation of HIV testing resources within the same spending amount, we found that general females received the highest proportion of spending allocation (45.1%), followed by low-risk men who have sex with men (13.9%) and pregnant women (8.4%). In contrast, the proportion of spending allocation for the general males decreased to 0.2%. With this optimized strategy, we estimated that 120,755 (83.4%) of annual new infections would be diagnosed within a year of acquisition, with the cost required for one HIV case detection reduced to $23,364/case. Further spending increases could allow for significant increases in HIV testing among lower-risk populations. CONCLUSIONS: Optimizing resource allocation for HIV testing in high-risk populations would improve HIV timely diagnosis rate of new infections and reduce cost per HIV case detection.

Clinical features-based machine learning models to separate sexually transmitted infections from other skin diagnoses.

INTRODUCTION: Many sexual health services are overwhelmed and cannot cater for all the individuals who present with sexually transmitted infections (STIs). Digital health software that separates STIs from non-STIs could improve the efficiency of clinical services. We developed and evaluated a machine learning model that predicts whether patients have an STI based on their clinical features. METHODS: We manually extracted 25 demographic features and clinical features from 1315 clinical records in the electronic health record system at Melbourne Sexual Health Center. We examined 16 machine learning models to predict a binary outcome of an STI or a non-STI diagnosis. We evaluated the models' performance with the area under the ROC curve (AUC), accuracy and F1-scores. RESULTS: Our study included 1315 consultations, of which 36.8% (484/1315) were diagnosed with STIs and 63.2% (831/1315) had non-STI conditions. The study population predominantly consisted of heterosexual men (49.5%, 651/1315), followed by gay, bisexual and other men who have sex with men (GBMSM) (25.7%), women (21.6%) and unknown gender (3.2%). The median age was 31 years (intra-quartile range (IQR) 26-39). The top 5 performing models were CatBoost (AUC 0.912), Random Forest (AUC 0.917), LightGBM (AUC 0.907), Gradient Boosting (AUC 0.905) and XGBoost (AUC 0.900). The best model, CatBoost, achieved an accuracy of 0.837, sensitivity of 0.776, specificity of 0.831, precision of 0.782 and F1-score of 0.778. The key important features were lesion duration, type of skin lesions, age, gender, history of skin disorders, number of lesions, dysuria duration, anorectal pain and itchiness. CONCLUSIONS: Our best model demonstrates a reasonable performance in distinguishing STIs from non-STIs. However, to be clinically useful, more detailed information such as clinical images, may be required to reach sufficient accuracy.

Predictors of liver disease progression in people living with HIV-HBV co-infection on antiretroviral therapy.

BACKGROUND: In people living with HIV-HBV, liver fibrosis progression can occur even with suppressive antiretroviral therapy (ART). We investigated the relationship between liver fibrosis and biomarkers of inflammation, apoptosis, and microbial translocation. METHODS: In this observational cohort study adults living with HIV-HBV already on effective ART were recruited in Australia and Thailand and followed for 3 years including 6 monthly clinical review and blood tests and annual transient elastography. Differences in clinical and laboratory predictors of liver fibrosis progression were tested followed by regression analysis adjusted for CD4+ T-cells at study entry. A linear mixed model was fitted to longitudinal data to explore changes over time. FINDINGS: 67 participants (85% male, median age 49 y) were followed for 175 person-years. Median duration of ART was 10 years (interquartile range (IQR) 8-16 years). We found 11/59 (19%) participants during 3-years follow-up (6/100 person-years) met the primary endpoint of liver disease progression, defined as increased Metavir stage from baseline to final scan. In regression analysis, progressors compared to non-progressors had higher levels of high mobility group box 1 protein (HGMB1), (median (IQR) 3.7 (2.6-5.0) and 2.4 ng/mL (1.5-3.4) respectively, adjusted relative risk 1.47, 95% CI [1.00, 2.17]) and lower nadir CD4+ T-cell percentage (median 4% (IQR 2-8) and 11% (4-15) respectively (relative risk 0.93, 95% CI [0.88, 0.98]). INTERPRETATION: Progression in liver fibrosis occurs in people with HIV-HBV on suppressive ART. Fibrosis progression was associated with higher HMGB1 and lower percentage nadir CD4+ T-cell count, highlighting the importance of early initiation of HBV-active ART. FUNDING: This work was supported by NHMRC project grant 1101836; NHMRC practitioner fellowship 1138581 and NHMRC program grant 1149990. The funder had no role in study design, data collection, data analysis, interpretation, writing of this manuscript or decision to submit for publication.