Impact of simplified HCV diagnostic strategies on the HCV epidemic among men who have sex with men in the era of HIV oral pre-exposure prophylaxis in Taiwan: a modelling study.

INTRODUCTION: Simplified hepatitis C virus (HCV) diagnostic strategies have the potential to improve HCV diagnoses and treatment. We aimed to investigate the impact of simplified HCV diagnostic strategies on HCV incidence and its effect on HCV diagnosis and treatment among men who have sex with men (MSM) regardless of HIV status and use of HIV pre-exposure prophylaxis (PrEP) in Taiwan. METHODS: A compartmental deterministic model was developed to describe the natural history of HCV disease progression, the HCV care cascade and the HIV status and PrEP using among MSM. The model was calibrated to available data for HCV and HIV epidemiology and population demographics in Taiwan. We simulated the epidemic from 2004 and projected the impact of simplified testing strategies on the HCV epidemic among MSM over 2022-2030. RESULTS: Under the current testing approach in Taiwan, total HCV incidence would increase to 12.6 per 1000 person-years among MSM by 2030. Single-visit point-of-care RNA testing had the largest impact on reducing the number of new HCV infections over 2022-2030, with a 31.1% reduction (interquartile range: 24.9%-32.8%). By 2030, single-visit point-of-care HCV testing improved HCV diagnosis to 90.9%, HCV treatment to 87.7% and HCV cure to 81.5% among MSM living with HCV. Compared to status quo, prioritized simplified HCV testing for PrEP users and MSM living with diagnosed HIV had considerable impact on the broader HCV epidemic among MSM. A sensitivity analysis suggests that reinfection risk would have a large impact on the effectiveness of each point-of-care testing scenario. CONCLUSIONS: Simplified HCV diagnostic strategies could control the ongoing HCV epidemic and improve HCV testing and treatment among Taiwanese MSM. Single-visit point-of-care RNA testing would result in large reductions in HCV incidence and prevalence among MSM. Efficient risk-reduction strategies will need to be implemented alongside point-of-care testing to achieve HCV elimination among MSM in Taiwan.

Preparing correctional settings for the next pandemic: a modeling study of COVID-19 outbreaks in two high-income countries.

Introduction: Correctional facilities are high-priority settings for coordinated public health responses to the COVID-19 pandemic. These facilities are at high risk of disease transmission due to close contacts between people in prison and with the wider community. People in prison are also vulnerable to severe disease given their high burden of co-morbidities. Methods: We developed a mathematical model to evaluate the effect of various public health interventions, including vaccination, on the mitigation of COVID-19 outbreaks, applying it to prisons in Australia and Canada. Results: We found that, in the absence of any intervention, an outbreak would occur and infect almost 100% of people in prison within 20 days of the index case. However, the rapid rollout of vaccines with other non-pharmaceutical interventions would almost eliminate the risk of an outbreak. Discussion: Our study highlights that high vaccination coverage is required for variants with high transmission probability to completely mitigate the outbreak risk in prisons.

Optimizing point-of-care testing strategies for diagnosis and treatment of hepatitis C virus infection in Australia: a model-based cost-effectiveness analysis.

Background: Timely diagnosis and treatment of hepatitis C virus (HCV) is critical to achieve elimination goals. This study evaluated the cost-effectiveness of point-of-care testing strategies for HCV compared to laboratory-based testing in standard-of-care. Methods: Cost-effectiveness analyses were undertaken from the perspective of Australian Governments as funders by modelling point-of-care testing strategies compared to standard-of-care in needle and syringe programs, drug treatment clinics, and prisons. Point-of-care testing strategies included immediate point-of-care HCV RNA testing and combined point-of-care HCV antibody and reflex RNA testing for HCV antibody positive people (with and without consideration of previous treatment). Sensitivity analyses were performed to investigate the cost per treatment initiation with different testing strategies at different HCV antibody prevalence levels. Findings: The average costs per HCV treatment initiation by point-of-care testing, from A$890 to A$1406, were up to 35% lower compared to standard-of-care ranging from A$1248 to A$1632 depending on settings. The average costs per treatment initiation by point-of-care testing for three settings ranged from A$1080 to A$1406 for RNA, A$960-A$1310 for combined antibody/RNA without treatment history consideration, and A$890-A$1189 for combined antibody/RNA with treatment history consideration. When HCV antibody prevalence was <74%, combined point-of-care HCV antibody and point-of-care RNA testing were the most cost-effective strategies. Modest increases in treatment uptake by 8%-31% were required for immediate point-of-care HCV RNA testing to achieve equivalent cost per treatment initiation compared to standard-of-care. Interpretation: Point-of-care testing is more cost-effective than standard of care for populations at risk of HCV. Testing strategies combining point-of-care HCV antibody and RNA testing are likely to be cost-effective in most settings. Funding: National Health and Medical Research Council.

Impact of increased antiretroviral therapy use during the treatment as prevention era in Australia.

BACKGROUND: We analysed the impact of increased antiretroviral therapy (ART) on HIV epidemiology and healthcare costs in Australia during the 'Treatment-as-prevention' and 'Undetectable equals Untransmissible (U=U)' eras. METHODS: We conducted a retrospective modelling analysis between 2009 and 2019 to calculate the potential impact of early initiation of ART and treatment-as-prevention on HIV among gay and bisexual men (GBM). The model incorporates the change in the proportion diagnosed, treated, and virally suppressed, as well as the scale-up of oral HIV pre-exposure prophylaxis (PrEP) and the change in sexual behaviour during this period. We simulated a baseline and a no ART increase scenario and conducted a costing analysis from a national health provider perspective with cost estimates in 2019 AUD. RESULTS: Increasing ART use between 2009 and 2019 averted an additional 1624 [95% percentile interval (PI): 1220-2099] new HIV infections. Without the increase in ART, the number of GBM with HIV would have increased from 21 907 (95% PI: 20 753-23 019) to 23 219 (95% PI: 22 008-24 404) by 2019. HIV care and treatment costs for people with HIV increased by $296 (95% PI: $235-367) million AUD (assuming no change in annual healthcare costs). This was offset by a decrease in the lifetime HIV costs (with 3.5% discounting) for those newly infected of $458 (95% PI: $344-592) million AUD, giving a net cost saving of $162 (95%: $68-273) million AUD (and a benefits-to-cost ratio of 1.54). CONCLUSIONS: Increasing the proportion of Australian GBM on effective ART between 2009 and 2019 likely resulted in substantial reductions in new HIV infections and cost savings.

A population-level application of a method for estimating the timing of HIV acquisition among migrants to Australia.

INTRODUCTION: Australia has set the goal for the virtual elimination of HIV transmission by the end of 2022, yet accurate information is lacking on the level of HIV transmission occurring among residents. We developed a method for estimating the timing of HIV acquisition among migrants, relative to their arrival in Australia. We then applied this method to surveillance data from the Australian National HIV Registry with the aim of ascertaining the level of HIV transmission among migrants to Australia occurring before and after migration, and to inform appropriate local public health interventions. METHODS: We developed an algorithm incorporating CD4+ T-cell decline back-projection and enhanced variables (clinical presentation, past HIV testing history and clinician estimate of the place of HIV acquisition) and compared it to a standard algorithm which uses CD4+ T-cell back-projection only. We applied both algorithms to all new HIV diagnoses among migrants to estimate whether HIV infection occurred before or after arrival in Australia. RESULTS: Between 1 January 2016 and 31 December 2020, 1909 migrants were newly diagnosed with HIV in Australia, 85% were men, and the median age was 33 years. Using the enhanced algorithm, 932 (49%) were estimated to have acquired HIV after arrival in Australia, 629 (33%) before arrival (from overseas), 250 (13%) close to arrival and 98 (5%) were unable to be classified. Using the standard algorithm, 622 (33%) were estimated to have acquired HIV in Australia, 472 (25%) before arrival, 321 (17%) close to arrival and 494 (26%) were unable to be classified. CONCLUSIONS: Using our algorithm, close to half of migrants diagnosed with HIV were estimated to have acquired HIV after arrival in Australia, highlighting the need for tailored culturally appropriate testing and prevention programmes to limit HIV transmission and achieve elimination targets. Our method reduced the proportion of HIV cases unable to be classified and can be adopted in other countries with similar HIV surveillance protocols, to inform epidemiology and elimination efforts.

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.

Removing hepatitis C antibody testing for Australian blood donations: A cost-effectiveness analysis.

BACKGROUND AND OBJECTIVES: The risk of transfusion-transmitted hepatitis C virus (HCV) infections is extremely low in Australia. This study aims to conduct a cost-effectiveness analysis of different testing strategies for HCV infection in blood donations. MATERIALS AND METHODS: The four testing strategies evaluated in this study were universal testing with both HCV antibody (anti-HCV) and nucleic acid testing (NAT); anti-HCV and NAT for first-time donations and NAT only for repeat donations; anti-HCV and NAT for transfusible component donations and NAT only for plasma for further manufacture; and universal testing with NAT only. A decision-analytical model was developed to assess the cost-effectiveness of alternative HCV testing strategies. Sensitivity analysis and threshold analysis were conducted to account for data uncertainty. RESULTS: The number of potential transfusion-transmitted cases of acute hepatitis C and chronic hepatitis C was approximately zero in all four strategies. Universal testing with NAT only was the most cost-effective strategy due to the lowest testing cost. The threshold analysis showed that for the current practice to be cost-effective, the residual risks of other testing strategies would have to be at least 1 HCV infection in 2424 donations, which is over 60,000 times the baseline residual risk (1 in 151 million donations). CONCLUSION: The screening strategy for HCV in blood donations currently implemented in Australia is not cost-effective compared with targeted testing or universal testing with NAT only. Partial or total removal of anti-HCV testing would bring significant cost savings without compromising blood recipient safety.

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.

A HIV diagnosis and treatment cascade for Aboriginal and Torres Strait Islander peoples of Australia.

Aboriginal and Torres Strait Islander (hereafter Aboriginal) people are a priority population for HIV care in Australia; however, no HIV cascade exists for this population. We developed annual HIV cascades for 2010-2017 specific to Aboriginal peoples. By 2017, an estimated 595 Aboriginal people were living with HIV (PLWH); however, 14% remained undiagnosed. Cascade steps below global targets were: PLWH aware of their diagnosis (86%), and retention in care (81% of those who had received any care in previous two years in a sentinel network of clinics). For people retained in care, treatment outcomes surpassed global targets (92% receiving treatment, 93% viral suppression). Increases occurred across all HIV cascade steps over time; however, the least improvement was for retention in care, while the greatest improvement was achieving viral suppression. The HIV cascade for Aboriginal peoples highlights both gaps and strengths in the Australian HIV care system, and importantly highlights where potential interventions may be required to achieve the global UNAIDS targets.

Assessing the Impact of HIV Preexposure Prophylaxis Scale-Up on Gonorrhea Incidence Among Gay and Bisexual Men in Sydney: A Mathematical Modeling Study.

BACKGROUND: The rollout of preexposure prophylaxis (PrEP) for HIV prevention among gay and bisexual men (GBM) is associated with increases in condomless anal intercourse, potentially increasing the incidence of other sexually transmissible infections (STIs). METHODS: We developed an individual-based mathematical model to simulate the transmission of Neisseria gonorrhoeae among GBM in Sydney, accounting for changes in sexual practices, STI testing, and PrEP use. We calibrated and validated the model using reported incidence rates for HIV-positive and HIV-negative GBM from 2010 to 2019. Scenarios were run with varying PrEP uptake, PrEP-related STI testing, and PrEP-related sexual behavior and testing intervals up to 2030 to assess the impact of PrEP use on gonorrhea incidence. RESULTS: Preexposure prophylaxis uptake and associated 3-monthly STI testing from 2015 onward resulted in a predicted increase from 20 to 37 N. gonorrhoeae infections per 100 person-years among HIV-negative GBM by the end of 2020. This is lower than the counterfactual predictions of 45 per 100 person-years if PrEP were not scaled up and 48 per 100 person-years with nonadherence to 3-monthly STI testing. Increasing the time between STI tests for PrEP users by 1 month from 2018 results in the incidence rate among HIV-negative GBM increasing by 8% by 2030. If PrEP coverage doubles from 24% to 53%, incidence among HIV-negative GBM declines by ~25% by 2030. CONCLUSIONS: Behavior change due to widespread PrEP use may lead to significant increases in gonorrhea incidence in GBM, but the recommended quarterly STI testing recommended for PrEP users should reduce incidence by 18% by 2030.

Impact of Testing Strategies to Combat a Major Syphilis Outbreak Among Australian Aboriginal and Torres Strait Islander Peoples: A Mathematical Modeling Study.

Background: A syphilis outbreak among Australian Aboriginal and Torres Strait Islander people (respectfully referred to as Aboriginal) has resulted in almost 4000 notifications by 2020, with several congenital syphilis cases and infant deaths. Outbreak control efforts became coordinated under a National enhanced test and treat response in 2017. We evaluated the impact of these efforts and of expansion of testing interventions on syphilis prevalence. Methods: We developed an individual-based mathematical model of infectious syphilis transmission among young heterosexual Aboriginal people aged 15-34 years living in and moving between regional and remote areas, and we assessed the impact of existing and hypothetical outbreak control responses on syphilis prevalence. Results: The increased testing coverage achieved through the response (from 18% to 39% over 2011-2020) could stabilize the epidemic from 2021. To return to pre-outbreak prevalence (<0.24%) by 2025, testing coverage must reach 60%. The addition of annual community-wide screening, where 30% of youth in communities are tested over 6 weeks, would reduce prevalence to the pre-outbreak level within 4 years. If testing coverage had been scaled-up to 60% at the start of outbreak in mid-2011, the outbreak would have been mitigated. Conclusions: Our results suggest that to control the syphilis outbreak, the response needs to be delivered to enable the maximum coverage of testing to be reached in the shortest time to reduce the prevalence to pre-outbreak levels. Reduction could be hastened with community-wide screening at similar time periods across all communities together with increases in annual testing coverage.

A Gonococcal Vaccine Has the Potential to Rapidly Reduce the Incidence of Neisseria gonorrhoeae Infection Among Urban Men Who Have Sex With Men.

BACKGROUND: A gonococcal vaccine is urgently needed due to increasing gonorrhea incidence and emerging multidrug-resistant gonococcal strains worldwide. Men who have sex with men (MSM) have among the highest incidences of gonorrhea and may be a key target population for vaccination when available. METHODS: An individual-based, anatomical site-specific mathematical model was used to simulate Neisseria gonorrhoeae transmission in a population of 10 000 MSM. The impact of vaccination on gonorrhea prevalence was assessed. RESULTS: With a gonococcal vaccine of 100% or 50% protective efficacy, gonorrhea prevalence could be reduced by 94% or 62%, respectively, within 2 years if 30% of MSM are vaccinated on presentation for sexually transmitted infection (STI) testing. Elimination of gonorrhea is possible within 8 years with vaccines of ≥ 50% efficacy lasting 2 years, providing a booster vaccination is available every 3 years on average. A vaccine's impact may be reduced if it is not effective at all anatomical sites. CONCLUSIONS: Our study indicates that with a vaccine of modest efficacy and an immunization strategy that targets MSM presenting for STI screening, the prevalence of gonorrhea in this population could be rapidly and substantially reduced.

Australia could miss the WHO hepatitis C virus elimination targets due to declining treatment uptake and ongoing burden of advanced liver disease complications.

Australia was one of the first countries to introduce government-funded unrestricted access to direct-acting antiviral (DAA) therapy, with 88,790 treated since March 2016. However, treatment uptake is declining which could potentially undermine Australia's progress towards the WHO HCV elimination targets. Using mathematical modelling, we updated estimates for those living with chronic HCV in Australia, new cases of decompensated cirrhosis (DC), hepatocellular carcinoma (HCC), and liver-related mortality among the HCV-cured and viraemic populations from 2015 to 2030. We considered various DAA treatment scenarios incorporating annual treatment numbers to 2020, and subsequent uptake per year of 6,790 (pessimistic), 8,100 (intermediate), and 11,310 (optimistic). We incorporated the effects of excess alcohol consumption and reduction in progression to DC and HCC among cirrhosis-cured versus viraemic individuals. At the end of 2020, we estimated 117,810 Australians were living with chronic HCV. New cases per year of DC, HCC, and liver-related mortality among the HCV viraemic population decreased rapidly from 2015 (almost eliminated by 2030). In contrast, the growing population size of those cured with advanced liver disease meant DC, HCC, and liver-related mortality declined slowly. The estimated reduction in liver-related mortality from 2015 to 2030 in the combined HCV viraemic and cured population is 25% in the intermediate scenario. With declining HCV treatment uptake and ongoing individual-level risk of advanced liver disease complications, including among cirrhosis-cured individuals, Australia is unlikely to achieve all WHO HCV elimination targets by 2030.

Understanding COVID-19 dynamics and the effects of interventions in the Philippines: A mathematical modelling study.

BACKGROUND: COVID-19 initially caused less severe outbreaks in many low- and middle-income countries (LMIC) compared with many high-income countries, possibly because of differing demographics, socioeconomics, surveillance, and policy responses. Here, we investigate the role of multiple factors on COVID-19 dynamics in the Philippines, a LMIC that has had a relatively severe COVID-19 outbreak. METHODS: We applied an age-structured compartmental model that incorporated time-varying mobility, testing, and personal protective behaviors (through a "Minimum Health Standards" policy, MHS) to represent the first wave of the Philippines COVID-19 epidemic nationally and for three highly affected regions (Calabarzon, Central Visayas, and the National Capital Region). We estimated effects of control measures, key epidemiological parameters, and interventions. FINDINGS: Population age structure, contact rates, mobility, testing, and MHS were sufficient to explain the Philippines epidemic based on the good fit between modelled and reported cases, hospitalisations, and deaths. The model indicated that MHS reduced the probability of transmission per contact by 13-27%. The February 2021 case detection rate was estimated at ~8%, population recovered at ~9%, and scenario projections indicated high sensitivity to MHS adherence. INTERPRETATION: COVID-19 dynamics in the Philippines are driven by age, contact structure, mobility, and MHS adherence. Continued compliance with low-cost MHS should help the Philippines control the epidemic until vaccines are widely distributed, but disease resurgence may be occurring due to a combination of low population immunity and detection rates and new variants of concern.

Role of masks, testing and contact tracing in preventing COVID-19 resurgences: a case study from New South Wales, Australia.

OBJECTIVES: The early stages of the COVID-19 pandemic illustrated that SARS-CoV-2, the virus that causes the disease, has the potential to spread exponentially. Therefore, as long as a substantial proportion of the population remains susceptible to infection, the potential for new epidemic waves persists even in settings with low numbers of active COVID-19 infections, unless sufficient countermeasures are in place. We aim to quantify vulnerability to resurgences in COVID-19 transmission under variations in the levels of testing, tracing and mask usage. SETTING: The Australian state of New South Wales (NSW), a setting with prolonged low transmission, high mobility, non-universal mask usage and a well-functioning test-and-trace system. PARTICIPANTS: None (simulation study). RESULTS: We find that the relative impact of masks is greatest when testing and tracing rates are lower and vice versa. Scenarios with very high testing rates (90% of people with symptoms, plus 90% of people with a known history of contact with a confirmed case) were estimated to lead to a robustly controlled epidemic. However, across comparable levels of mask uptake and contact tracing, the number of infections over this period was projected to be 2-3 times higher if the testing rate was 80% instead of 90%, 8-12 times higher if the testing rate was 65% or 30-50 times higher with a 50% testing rate. In reality, NSW diagnosed 254 locally acquired cases over this period, an outcome that had a moderate probability in the model (10%-18%) assuming low mask uptake (0%-25%), even in the presence of extremely high testing (90%) and near-perfect community contact tracing (75%-100%), and a considerably higher probability if testing or tracing were at lower levels. CONCLUSIONS: Our work suggests that testing, tracing and masks can all be effective means of controlling transmission. A multifaceted strategy that combines all three, alongside continued hygiene and distancing protocols, is likely to be the most robust means of controlling transmission of SARS-CoV-2.

Hepatitis C treatment strategies in prisons: A cost-effectiveness analysis.

In Australian prisons approximately 20% of inmates are chronically infected with hepatitis C virus (HCV), providing an important population for targeted treatment and prevention. A dynamic mathematical model of HCV transmission was used to assess the impact of increasing direct-acting antiviral (DAA) treatment uptake on HCV incidence and prevalence in the prisons in New South Wales, Australia, and to assess the cost-effectiveness of alternate treatment strategies. We developed four separate models reflecting different average prison lengths of stay (LOS) of 2, 6, 24, and 36 months. Each model considered four DAA treatment coverage scenarios of 10% (status-quo), 25%, 50%, and 90% over 2016-2045. For each model and scenario, we estimated the lifetime burden of disease, costs and changes in quality-adjusted life years (QALYs) in prison and in the community during 2016-2075. Costs and QALYs were discounted 3.5% annually and adjusted to 2015 Australian dollars. Compared to treating 10% of infected prisoners, increasing DAA coverage to 25%, 50%, and 90% reduced HCV incidence in prisons by 9-33% (2-months LOS), 26-65% (6-months LOS), 37-70% (24-months LOS), and 35-65% (36-months LOS). DAA treatment was highly cost-effective among all LOS models at conservative willingness-to-pay thresholds. DAA therapy became increasingly cost-effective with increasing coverage. Compared to 10% treatment coverage, the incremental cost per QALY ranged from $497-$569 (2-months LOS), -$280-$323 (6-months LOS), -$432-$426 (24-months LOS), and -$245-$477 (36-months LOS). Treating more than 25% of HCV-infected prisoners with DAA therapy is highly cost-effective. This study shows that treating HCV-infected prisoners is highly cost-effective and should be a government priority for the global HCV elimination effort.

Gaps in the HIV diagnosis and care cascade for migrants in Australia, 2013-2017: A cross-sectional study.

BACKGROUND: Globally, few studies compare progress toward the Joint United Nations Program on HIV/AIDS (UNAIDS) Fast-Track targets among migrant populations. Fast-Track targets are aligned to the HIV diagnosis and care cascade and entail achieving 90-90-90 (90% of people living with HIV [PLHIV] diagnosed, 90% of those diagnosed on treatment, and 90% of those on treatment with viral suppression [VS]) by 2020 and 95-95-95 by 2030. We compared cascades between migrant and nonmigrant populations in Australia. METHODS AND FINDINGS: We conducted a serial cross-sectional survey for HIV diagnosis and care cascades using modelling estimates for proportions diagnosed combined with a clinical database for proportions on treatment and VS between 2013-2017. We estimated the number of PLHIV and number diagnosed using New South Wales (NSW) and Victorian (VIC) data from the Australian National HIV Registry. Cascades were stratified by migration status, sex, HIV exposure, and eligibility for subsidised healthcare in Australia (reciprocal healthcare agreement [RHCA]). We found that in 2017, 17,760 PLHIV were estimated in NSW and VIC, and 90% of them were males. In total, 90% of estimated PLHIV were diagnosed. Of the 9,391 who were diagnosed and retained in care, most (85%; n = 8,015) were males. We excluded 38% of PLHIV with missing data for country of birth, and 41% (n = 2,408) of eligible retained PLHIV were migrants. Most migrants were from Southeast Asia (SEA; 28%), northern Europe (12%), and eastern Asia (11%). Most of the migrants and nonmigrants were males (72% and 83%, respectively). We found that among those retained in care, 90% were on antiretroviral therapy (ART), and 95% of those on ART had VS (i.e., 90-90-95). Migrants had larger gaps in their HIV diagnosis and care cascade (85-85-93) compared with nonmigrants (94-90-96). Similarly, there were larger gaps among migrants reporting male-to-male HIV exposure (84-83-93) compared with nonmigrants reporting male-to-male HIV exposure (96-92-96). Large gaps were also found among migrants from SEA (72-87-93) and sub-Saharan Africa (SSA; 89-93-91). Migrants from countries ineligible for RHCA had lower cascade estimates (83-85-92) than RHCA-eligible migrants (96-86-95). Trends in the HIV diagnosis and care cascades improved over time (2013 and 2017). However, there was no significant increase in ART coverage among migrant females (incidence rate ratio [IRR]: 1.03; 95% CI 0.99-1.08; p = 0.154), nonmigrant females (IRR: 1.01; 95% CI 0.95-1.07; p = 0.71), and migrants from SEA (IRR: 1.03; 95% CI 0.99-1.07; p = 0.06) and SSA (IRR: 1.03; 95% CI 0.99-1.08; p = 0.11). Additionally, there was no significant increase in VS among migrants reporting male-to-male HIV exposure (IRR: 1.02; 95% CI 0.99-1.04; p = 0.08). The major limitation of our study was a high proportion of individuals missing data for country of birth, thereby limiting migrant status categorisation. Additionally, we used a cross-sectional instead of a longitudinal study design to develop the cascades and used the number retained as opposed to using all individuals diagnosed to calculate the proportions on ART. CONCLUSIONS: HIV diagnosis and care cascades improved overall between 2013 and 2017 in NSW and VIC. Cascades for migrants had larger gaps compared with nonmigrants, particularly among key migrant populations. Tracking subpopulation cascades enables gaps to be identified and addressed early to facilitate achievement of Fast-Track targets.

Can Australia Reach the World Health Organization Hepatitis C Elimination Goal by 2025 Among Human Immunodeficiency Virus-positive Gay and Bisexual Men?

BACKGROUND: Human immunodeficiency virus (HIV)-positive gay and bisexual men (GBM) in Australia are well engaged in care. The World Health Organization's (WHO) hepatitis C virus (HCV) elimination target of an 80% reduction in incidence by 2030 may be reachable ahead of time in this population. METHODS: We predicted the effect of treatment and behavioral changes on HCV incidence among HIV-positive GBM up to 2025 using a HCV transmission model parameterized with Australian data. We assessed the impact of changes in behavior that facilitate HCV transmission in the context of different rates of direct-acting antiviral (DAA) use. RESULTS: HCV incidence in our model increased from 0.7 per 100 person-years in 2000 to 2.5 per 100 person-years in 2016 and had the same trajectory as previously reported clinical data. If the proportion of eligible (HCV RNA positive) patients using DAAs stays at 65% per year between 2016 and 2025, with high-risk sexual behavior and injecting drug use remaining at current levels, HCV incidence would drop to 0.4 per 100 person-years (85% decline from 2016). In the same treatment scenario but with substantial increases in risk behavior, HCV incidence would drop to 0.6 per 100 person-years (76% decline). If the proportion of eligible patients using DAAs dropped from 65% per year in 2016 to 20% per year in 2025 and risk behavior did not change, HCV incidence would drop to 0.7 per 100 person-years (70% reduction). CONCLUSIONS: Reaching the WHO HCV elimination target by 2025 among HIV-positive GBM in Australia is achievable.

Population-level diagnosis and care cascade for chlamydia in Australia.

OBJECTIVES: Key strategies to control chlamydia include testing, treatment, partner management and re-testing. We developed a diagnosis and care cascade for chlamydia to highlight gaps in control strategies nationally and to inform efforts to optimise control programmes. METHODS: The Australian Chlamydia Cascade was organised into four steps: (1) annual number of new chlamydia infections (including re-infections); (2) annual number of chlamydia diagnoses; (3) annual number of diagnoses treated; (4) annual number of diagnoses followed by a re-test for chlamydia within 42-180 days of diagnosis. For 2016, we estimated the number of infections among young men and women aged 15-29 years in each of these steps using a combination of mathematical modelling, national notification data, sentinel surveillance data and previous research studies. RESULTS: Among young people in Australia, there were an estimated 248 580 (range, 240 690-256 470) new chlamydia infections in 2016 (96 470 in women; 152 100 in men) of which 70 164 were diagnosed (28.2% overall: women 43.4%, men 18.6%). Of the chlamydia infections diagnosed, 65 490 (range, 59 640-70 160) were treated (93.3% across all populations), but only 11 330 (range, 7660-16 285) diagnoses were followed by a re-test within 42-180 days (17.3% overall: women 20.6%, men 12.5%) of diagnosis. CONCLUSIONS: The greatest gaps in the Australian Chlamydia Cascade for young people were in the diagnosis and re-testing steps, with 72% of infections undiagnosed and 83% of those diagnosed not re-tested: both were especially low among men. Treatment rates were also lower than recommended by guidelines. Our cascade highlights the need for enhanced strategies to improve treatment and re-testing coverage such as short message service reminders, point-of-care and postal test kits.

Comorbidity Medications Are Dispensed to More People Receiving Antiretroviral Therapy for HIV Compared with the General Population in Australia.

Medical comorbidities occur in more persons with HIV than without HIV. We used a nationally representative 10% sample of 2016 Pharmaceutical Benefits Scheme (PBS) dispensing data to compare the proportions of antiretroviral therapy (ART)-purchasing and non-ART-purchasing patients who also purchased prescriptions for medical comorbidities. Each patient who purchased ART was compared with two gender- and age group-matched patients who did not purchase ART in the same year. We calculated the proportions of patients who also purchased coprescriptions used for hypertension, dyslipidemia, diabetes, cancer, low bone mineral density, and mental health, defined using PBS medication coding categories, and the resulting odds ratios. A total of 1,973 ART-purchasing patients in our sample were matched to 3,946 non-ART-purchasing patients. Compared with non-ART-purchasing patients, a greater proportion of ART-purchasing patients also purchased medications for dyslipidemia (19.8% vs. 16.6%; p-value = .003), low bone mineral density (1.5% vs. 0.8%; p-value = .02), and mental health (29.1% vs. 15.3%; p-value < .0001); a lower proportion purchased diabetes medications (4.8% vs. 6.5%; p-value = .009). These differences remained when our analysis was restricted to persons >55 years of age. Rates of multimorbidity (dispensed ≥2 medications for chronic conditions) were also higher among ART-purchasing patients (19.0% vs. 15.9%; p-value = .003). Using a nationally representative sample of prescription dispensing data, we found that higher proportions of ART-purchasing patients purchased coprescriptions for common comorbidities compared with non-ART-purchasing patients. Our finding that ART-purchasing patients purchased fewer diabetes medications is surprising, but may reflect differences in population characteristics between our two groups.