Determining Herd Immunity Thresholds for Hepatitis A Virus Transmission to Inform Vaccination Strategies Among People Who Inject Drugs in 16†US States.

BACKGROUND: Widespread outbreaks of person-to-person transmitted hepatitis A virus (HAV), particularly among people who inject drugs (PWID), continue across the United States and globally. However, the herd immunity threshold and vaccination coverage required to prevent outbreaks are unknown. We used surveillance data and dynamic modeling to estimate herd immunity thresholds among PWID in 16 US states. METHODS: We used a previously published dynamic model of HAV transmission calibrated to surveillance data from outbreaks involving PWID in 16 states. Using state-level calibrated models, we estimated the basic reproduction number (R0) and herd immunity threshold for PWID in each state. We performed a meta-analysis of herd immunity thresholds to determine the critical vaccination coverage required to prevent most HAV outbreaks among PWID. RESULTS: Estimates of R0 for HAV infection ranged from 2.2 (95% confidence interval [CI], 1.9-2.5) for North Carolina to 5.0 (95% CI, 4.5-5.6) for West Virginia. Corresponding herd immunity thresholds ranged from 55% (95% CI, 47%-61%) for North Carolina to 80% (95% CI, 78%-82%) for West Virginia. Based on the meta-analysis, we estimated a pooled herd immunity threshold of 64% (95% CI, 61%-68%; 90% prediction interval, 52%-76%) among PWID. Using the prediction interval upper bound (76%) and assuming 95% vaccine efficacy, we estimated that vaccination coverage of 80% could prevent most HAV outbreaks. CONCLUSIONS: Hepatitis A vaccination programs in the United States may need to achieve vaccination coverage of at least 80% among PWID in order to prevent most HAV outbreaks among this population.

Incidence of hepatitis C virus infection in the prison setting: The SToP-C study.

People in prison are at high risk of HCV given high injecting drug use prevalence. This study evaluated HCV incidence and associated injecting drug use characteristics in prison. The SToP-C study enrolled people incarcerated in four Australian prisons. Participants were tested for HCV at enrolment and then every 3-6 months (October-2014 to November-2019). Participants eligible for this analysis included those at-risk of HCV primary infection (anti-HCV negative) or re-infection (anti-HCV positive, HCV RNA negative) with follow-up assessment. A total of 1643 eligible participants were included in analyses (82% male; median age 33 years; 30% injected drugs in prison; 1818 person-years of follow-up). Overall HCV incidence was 6.11/100 person-years (95%CI: 5.07-7.35), with higher rate of re-infection (9.34/100 person-years; 95%CI: 7.15-12.19) than primary infection (4.60/100 person-years; 95%CI: 3.56-5.96). In total population (n = 1643), HCV risk was significantly higher among participants injecting drugs in prison [vs. no injecting; adjusted hazard ratio (aHR): 10.55, 95%CI: 5.88-18.92), and those who were released and re-incarcerated during follow-up (vs. remained incarcerated; aHR: 1.60, 95%CI: 1.03-2.49). Among participants who injected recently (during past month, n = 321), HCV risk was reduced among those receiving high-dosage opioid agonist therapy (OAT), i.e. methadone ≥60 mg/day or buprenorphine ≥16 mg/day, (vs. no OAT, aHR: 0.11, 95%CI: 0.02-0.80) and increased among those sharing needles/syringes without consistent use of disinfectant to clean injecting equipment (vs. no sharing, HR: 4.60, 95%CI: 1.35-15.66). This study demonstrated high HCV transmission risk in prison, particularly among people injecting drugs. High-dosage OAT was protective, but improved OAT coverage and needle/syringe programmes to reduce sharing injecting equipment are required.

Relative Cost and Infectious Days Averted Associated With Rapid Gonorrhea and Chlamydia Testing Among Men Who Have Sex With Men.

BACKGROUND: Standard-of-care nucleic acid amplification tests (routine NAATs) for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) can take several days to result and therefore delay treatment. Rapid point-of-care GC/CT NAAT (rapid NAAT) could reduce the time to treatment and therefore onward transmission. This study evaluated the incremental cost per infectious day averted and overall cost of implementation associated with rapid compared with routine NAAT. METHODS: Prospective sexually transmitted infection (STI) treatment data from men who have sex with men and transgender women in San Diego who received rapid NAAT between November 2018 and February 2021 were evaluated. Historical time from testing to treatment for routine NAAT was abstracted from the literature. Costs per test for rapid and routine NAAT were calculated using a micro-costing approach. The incremental cost per infectious day averted comparing rapid to routine NAAT and the costs of rapid GC/CT NAAT implementation in San Diego Public Health STI clinics were calculated. RESULTS: Overall, 2333 individuals underwent rapid NAAT with a median time from sample collection to treatment of 2 days compared with 7 to 14 days for routine NAAT equating to a reduction of 5 to 12 days. The cost of rapid and routine GC/CT NAAT was $57.86 and $18.38 per test, respectively, with a cost-effectiveness of between $2.43 and $5.82 per infectious day averted. The incremental cost of rapid NAAT improved when at least 2000 tests were performed annually. CONCLUSIONS: Although rapid GC/CT NAAT is more expensive than routine testing, the reduction of infectious days between testing and treatment may reduce transmission and provide improved STI treatment services to patients.

Associations Between Alcohol Use, Antiretroviral Therapy Use, and Viral Load Suppression Among People Living with HIV in Rural Central Uganda.

Alcohol use among people living with HIV (PWH) is common and may negatively affect engagement in HIV care. We evaluated the relationships between alcohol use, ART use, and viral suppression among PWH in Uganda. PATH/Ekkubo was a trial evaluating a linkage to HIV care intervention in four Ugandan districts, Nov 2015-Sept 2021. Our analytical sample included: (1) baseline data from individuals not enrolled in the intervention trial (previously diagnosed HIV+); and 12-month follow-up data from the control group (newly diagnosed or previously diagnosed, but not in care). Level of alcohol use was categorized using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C): none (AUDIT-C = 0), low (women = 1-2, men = 1-3), medium (women = 3-5, men = 4-5), high/very high (6-12). Multivariable logistic regression models evaluated associations between alcohol use, ART use and viral suppression (a viral load of < 20); we also stratified by gender. Among 931 PWH, medium (OR: 0.43 [95% CI 0.25-0.72]) and high/very high (OR: 0.22 [95% CI 0.11-0.42]) levels of alcohol use were associated with lower odds of being on ART. In a sub-sample of 664, medium use (OR: 0.63 [95% CI 0.41-0.97]) was associated with lower odds of viral suppression. However, this association was not statistically significant when restricting to those on ART, suggesting the relationship between alcohol use and viral suppression is explained by ART use. Among men, high/very high, and among women, medium alcohol use levels were associated with lower odds of being on ART and being virally suppressed. Interventions for PWH who use higher levels of alcohol may be needed to optimize the benefits of Uganda's Universal Test and Treat strategy.

Prison-based interventions are key to achieving HCV elimination among people who inject drugs in New South Wales, Australia: A modelling study.

BACKGROUND & AIMS: People who inject drugs (PWID) experience high incarceration rates which are associated with increased hepatitis C virus (HCV) transmission risk. We assess the importance of prison-based interventions for achieving HCV elimination among PWID in New South Wales (NSW), Australia. METHODS: A model of incarceration and HCV transmission among PWID was calibrated in a Bayesian framework to epidemiological and incarceration data from NSW, incorporating elevated HCV acquisition risk among recently released PWID. We projected the contribution of differences in transmission risk during/following incarceration to HCV transmission over 2020-2029. We estimated the past and potential future impact of prison-based opioid agonist therapy (OAT; ~33% coverage) and HCV treatment (1500 treatments in 2019 with 32.9%-83.3% among PWID) on HCV transmission. We estimated the time until HCV incidence reduces by 80% (WHO elimination target) compared to 2016 levels with or without prison-based interventions. RESULTS: Over 2020-2029, incarceration will contribute 23.0% (17.9-30.5) of new HCV infections. If prison-based interventions had not been implemented since 2010, HCV incidence in 2020 would have been 29.7% (95% credibility interval: 22.4-36.1) higher. If current prison and community HCV treatment rates continue, there is an 98.8% probability that elimination targets will be achieved by 2030, with this decreasing to 10.1% without current prison-based interventions. CONCLUSIONS: Existing prison-based interventions in NSW are critical components of strategies to reduce HCV incidence among PWID. Prison-based interventions are likely to be pivotal for achieving HCV elimination targets among PWID by 2030.

Health-related quality of life among people who inject drugs in Australia.

PURPOSE: There is limited research on health-related quality of life (HRQoL) among people who inject drugs (PWID). We aimed to evaluate factors associated with HRQoL among a cohort of PWID in Australia. METHODS: Participants were enrolled in an observational cohort study (the LiveRLife Study) between 2014 and 2018 at 15 sites in Australia. They provided fingerstick whole-blood samples for point-of-care HCV RNA testing and underwent transient elastography to assess liver disease. Participants completed the EQ-5D-3L survey at enrolment. Regression models were used to assess the impact of clinical and socioeconomic characteristics on the EQ-5D-3L scores. RESULTS: Among 751 participants (median age, 43 years; 67% male), 63% reported injection drug use in the past month, 43% had current HCV infection, and 68% had no/mild liver fibrosis (F0/F1). The mean EQ-5D-3L and EQ-VAS scores were 0.67 and 62, respectively, for the overall study population. There was no significant difference in the EQ-5D-3L scores among people with and without recent injecting drug use (mean: 0.66 vs. 0.68, median: 0.73 vs. 0.78, P = 0.405), and among people receiving and not receiving opioid agonist therapy (mean: 0.66 vs. 0.68, median: 0.73 vs. 0.76, P = 0.215). Participants who were employed were found to have the highest mean EQ-5D-3L (0.83) and EQ-VAS scores (77). The presence of current HCV infection, liver fibrosis stage, and high-risk alcohol consumption had little impact on HRQoL. CONCLUSIONS: The study findings provide important HRQoL data for economic evaluations, useful for guiding the allocation of resources for HCV elimination strategies and interventions among PWID.

Sustained Impact of the Coronavirus Disease 2019 Pandemic on Hepatitis C Virus Treatment Initiations in the United States.

BACKGROUND: Recent reports indicated declines in hepatitis C virus (HCV) testing during the first half of 2020 in the United States due to coronavirus disease 2019 (COVID-19), but the longer-term impact on HCV testing and treatment is unclear. METHODS: We obtained monthly state-level volumes of HCV antibody, RNA and genotype testing, and HCV treatment initiation, stratified by age and gender, spanning January 2019 until December 2020 from 2 large national laboratories. We performed segmented regression analysis for each state from a mixed-effects Poisson regression model with month as the main fixed predictor and state as a random intercept. RESULTS: During the pre-COVID-19 period (January 2019-March 2020), monthly HCV antibody and genotype tests decreased slightly whereas RNA tests and treatment initiations remained stable. Between March and April 2020, there were declines in the number of HCV antibody tests (37% reduction, P < .001), RNA tests (37.5% reduction, P < .001), genotype tests (24% reduction, P = .023), and HCV treatment initiations (31%, P < .001). Starting April 2020 through the end of 2020, there were significant increases in month-to-month HCV antibody (P < .001), RNA (P = .035), and genotype tests (P = .047), but only antibody testing rebounded to pre-COVID-19 levels. HCV treatment initiations remained low after April 2020 throughout the remainder of the year. CONCLUSIONS: HCV testing and treatment dropped by >30% during April 2020 at the start of the COVID-19 pandemic, but although HCV testing increased again later in 2020, HCV treatment rates did not recover. Efforts should be made to link HCV-positive patients to treatment and revitalize HCV treatment engagement by healthcare providers.

Hepatitis C Virus Reinfection Following Direct-Acting Antiviral Treatment in the Prison Setting: The SToP-C Study.

BACKGROUND: Injection drug use (IDU) following treatment for hepatitis C virus (HCV) infection may lead to reinfection, particularly if access to harm reduction services is suboptimal. This study assessed HCV reinfection risk following direct-acting antiviral therapy within Australian prisons that had opioid agonist therapy (OAT) programs but did not have needle and syringe programs (NSPs). METHODS: The Surveillance and Treatment of Prisoners With Hepatitis C (SToP-C) study enrolled people incarcerated in 4 prisons between 2014 and 2019. Participants treated for HCV were followed every 3-6 months to identify reinfection (confirmed by sequencing). Reinfection incidence and associated factors were evaluated. RESULTS: Among 388 participants receiving treatment, 161 had available posttreatment follow-up and were included in analysis (92% male; median age, 33 years; 67% IDU in prison; median follow-up 9 months). Among those with recent (in the past month) IDU (n = 71), 90% had receptive needle/syringe sharing. During 145 person-years (PY) of follow-up, 18 cases of reinfection were identified. Reinfection incidence was 12.5/100 PY (95% confidence interval [CI]: 7.9-19.8) overall, increasing to 28.7/100 PY (95% CI: 16.3-50.6) among those with recent IDU and needle/syringe sharing. In adjusted analysis, recent IDU with needle/syringe sharing was associated with increased reinfection risk (adjusted hazard ratio [aHR], 4.74 [95% CI: 1.33-16.80]; P = .016) and longer HCV testing interval with decreased risk (ie, chance of detection; aHR, 0.41 per each month increase [95% CI: .26-.64]; P < .001). CONCLUSIONS: A high rate of HCV reinfection was observed within prison. Posttreatment surveillance and retreatment are -essential to limit the impact of reinfection. High-coverage OAT and NSPs should be considered within prisons. CLINICAL TRIALS REGISTRATION: NCT02064049.

Evaluating the Prevention Benefit of HCV Treatment: Modeling the SToP-C Treatment as Prevention Study in Prisons.

BACKGROUND AND AIMS: Between 2014 and 2019, the SToP-C trial observed a halving in HCV incidence in four Australian prisons following scale-up of direct-acting antiviral (DAA) therapy. However, the contribution of HCV treatment to this decline is unclear because the study did not have a control group. We used modeling to consider this question. APPROACH AND RESULTS: We parameterized and calibrated a dynamic model of HCV transmission in prisons to data from each SToP-C prison on incarceration dynamics, injecting drug use, HCV prevalence trends among prison entrants, baseline HCV incidence before treatment scale-up, and subsequent HCV treatment scale-up. The model projected the decrease in HCV incidence resulting from increases in HCV treatment and other effects. We assessed whether the model agreed better with observed reductions in HCV incidence overall and by prison if we included HCV treatment scale-up, and its prevention benefits, or did not. The model estimated how much of the observed decrease in HCV incidence was attributable to HCV treatment in prison. The model projected a decrease in HCV incidence of 48.5% (95% uncertainty interval [UI], 41.9-54.1) following treatment scale-up across the four prisons, agreeing with the observed HCV incidence decrease (47.6%; 95% CI, 23.4-64.2) from the SToP-C trial. Without any in-prison HCV treatment, the model indicated that incidence would have decreased by 7.2% (95% UI, -0.3 to 13.6). This suggests that 85.1% (95% UI, 72.6-100.6) of the observed halving in incidence was from HCV treatment scale-up, with the remainder from observed decreases in HCV prevalence among prison entrants (14.9%; 95% UI, -0.6 to 27.4). CONCLUSIONS: Our results demonstrate the prevention benefits of scaling up HCV treatment in prison settings. Prison-based DAA scale-up should be an important component of HCV elimination strategies.

Bridging the Gap Between Pilot and Scale-Up: A Model of Antenatal Testing for Curable Sexually Transmitted Infections From Botswana.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are common sexually transmitted infections (STIs) associated with adverse outcomes, yet most countries do not test and conduct syndromic management, which lacks sensitivity and specificity. Innovations allow for expanded STI testing; however, cost is a barrier. METHODS: Using inputs from a pilot program in Botswana, we developed a model among a hypothetical population of 50,000 pregnant women to compare 1-year costs and outcomes associated with 3 antenatal STI testing strategies: (1) point-of-care, (2) centralized laboratory, and (3) a mixed approach (point of care at high-volume sites, and hubs elsewhere), and syndromic management. RESULTS: Syndromic management had the lowest delivery cost but was associated with the most infections at delivery, uninfected women treated, CT/NG-related low-birth-weight infants, disability-adjusted life years, and low birth weight hospitalization costs. Point-of-care CT/NG testing would treat and cure the most infections but had the highest delivery cost. Among the testing scenarios, the mixed scenario had the most favorable cost per woman treated and cured ($534/cure). Compared with syndromic management, the mixed approach resulted in a mean incremental cost-effectiveness ratio of $953 per disability-adjusted life years averted, which is cost-effective under World Health Organization's one-time per-capita gross domestic product willingness-to-pay threshold. CONCLUSIONS: As countries consider new technologies to strengthen health services, there is an opportunity to determine how to best deploy resources. Compared with point-of-care, centralized laboratory, and syndromic management, the mixed approach offered the lowest cost per infection averted and is cost-effective if policy makers' willingness to pay is informed by the World Health Organization's gross domestic product/capita threshold.

Network methods and design of randomized trials: Application to investigation of COVID-19 vaccination boosters.

Network science methods can be useful in design, monitoring, and analysis of randomized trials for control of spread of infections. Their usefulness arises from the role of statistical network models in molecular epidemiology and in study design. Computational models, such as agent-based models that propagate disease on simulated contact networks, can be used to investigate the properties of different study designs and analysis plans. Particularly valuable is the use of these methods to assess how magnitude and detectability of intervention effects depend on both individual-level and network-level characteristics of the enrolled populations. Such investigation also provides an important approach to assessing consequences of study data being incomplete or measured with error. To address these goals, we consider two statistical network models: exponential random graph models and the more flexible congruence class models. We focus first on an historical use of these methods in design and monitoring of a cluster randomized trial in Botswana to evaluate the effect of combination HIV prevention modalities compared to standard of care on HIV incidence. We then present a framework for the design of a study of booster vaccine effects on infection with, and forward transmission of, SARS-CoV-2 variants. Motivation for the study is driven in part by guidance from the United Kingdom to base approval of booster vaccines with "strain changes" that target variants on results of neutralizing antibody tests and information about safety, but without requiring evidence of clinical efficacy. Using designs informed by our agent-based network models, we show it may be feasible to conduct a trial of novel SARS-CoV-2 vaccines in a single large campus to obtain useful information regarding vaccine efficacy against susceptibility and infectiousness. If needed, the sample size could be increased by extending the study to a small number of campuses. Novel network methods may be useful in developing pragmatic SARS-CoV-2 vaccine trials that can leverage existing infrastructure to reduce costs and hasten the development of results.

Hepatitis C elimination among people who inject drugs in Mexico during the COVID-19 pandemic.

In 2019, Mexico was one of the first countries in Latin America to commit resources to achieve hepatitis C elimination by 2030. One year after this commitment, the global COVID-19 pandemic diverted attention to address immediate health needs to combat the spread of the disease. As a result, efforts to implement hepatitis C prevention and management programs were indefinitely postponed. Furthermore, populations at high risk of contracting the hepatitis C virus (HCV) and who bear the greatest burden of HCV national epidemic, including people who inject drugs and people who live with human immunodeficiency virus infection, remain exposed to extreme health disparities, which have potentially been exacerbated during the COVID-19 pandemic. In this article, we discuss the potential impact the COVID-19 pandemic has had on HCV elimination efforts in Mexico and the urgent need to resume them, since without these efforts, HCV elimination goals are likely not be achieved in the country by 2030.

En 2019, México fue uno de los primeros países en Latinoamérica en comprometer recursos para eliminar la hepatitis C antes de 2030. Un año después de este compromiso, la pandemia mundial de COVID-19 desvió la atención hacia las necesidades inmediatas de salud para combatir la propagación de esta última. Como resultado, los esfuerzos para implementar programas de prevención y manejo de la hepatitis C se suspendieron indefinidamente. Asimismo, las poblaciones con alto riesgo de contraer el virus de la hepatitis C y que representan el mayor peso de la epidemia nacional, como las personas que se inyectan drogas y las personas que viven con infección por el virus de la inmunodeficia humana, permanecen expuestas a disparidades de salud extremas que potencialmente se han exacerbado durante la pandemia de COVID-19. En este artículo discutimos el impacto potencial que la pandemia de COVID-19 ha tenido sobre los esfuerzos de eliminación de la hepatitis C en México y la necesidad urgente de reanudarlos, ya que sin ellos los objetivos de eliminación no se alcanzarán en el país en 2030.

Evaluation of Severe Acute Respiratory Syndrome Coronavirus 2 Transmission Mitigation Strategies on a University Campus Using an Agent-Based Network Model.

Universities are faced with decisions on how to resume campus activities while mitigating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) risk. To provide guidance for these decisions, we developed an agent-based network model of SARS-CoV-2 transmission to assess the potential impact of strategies to reduce outbreaks. The model incorporates important features related to risk at the University of California San Diego. We found that structural interventions for housing (singles only) and instructional changes (from in-person to hybrid with class size caps) can substantially reduce the basic reproduction number, but masking and social distancing are required to reduce this to at or below 1. Within a risk mitigation scenario, increased frequency of asymptomatic testing from monthly to twice weekly has minimal impact on average outbreak size (1.1-1.9), but substantially reduces the maximum outbreak size and cumulative number of cases. We conclude that an interdependent approach incorporating risk mitigation, viral detection, and public health intervention is required to mitigate risk.

Cost-effectiveness of Antenatal Rescreening Among Pregnant Women for Hepatitis C in the United States.

To inform proposed changes in hepatitis C virus (HCV) screening guidelines in the United States, we assessed the cost-effectiveness of HCV antenatal rescreening for women without evidence of HCV during a prior pregnancy, using a previously published model. Universal HCV rescreening among pregnant women was cost-effective (incremental cost-effectiveness ratio, $6000 per quality-adjusted life-year) and should be recommended nationally.

Cost-effectiveness of using hepatitis C viremic hearts for transplantation into HCV-negative recipients.

Outcomes following hepatitis C virus (HCV)-viremic heart transplantation into HCV-negative recipients with HCV treatment are good. We assessed cost-effectiveness between cohorts of transplant recipients willing and unwilling to receive HCV-viremic hearts. Markov model simulated long-term outcomes among HCV-negative patients on the transplant waitlist. We compared costs (2018 USD) and health outcomes (quality-adjusted life-years, QALYs) between cohorts willing to accept any heart and those willing to accept only HCV-negative hearts. We assumed 4.9% HCV-viremic donor prevalence. Patients receiving HCV-viremic hearts were treated, assuming $39 600/treatment with 95% cure. Incremental cost-effectiveness ratios (ICERs) were compared to a $100 000/QALY gained willingness-to-pay threshold. Sensitivity analyses included stratification by blood type or region and potential negative consequences of receipt of HCV-viremic hearts. Compared to accepting only HCV-negative hearts, accepting any heart gained 0.14 life-years and 0.11 QALYs, while increasing costs by $9418/patient. Accepting any heart was cost effective (ICER $85 602/QALY gained). Results were robust to all transplant regions and blood types, except type AB. Accepting any heart remained cost effective provided posttransplant mortality and costs among those receiving HCV-viremic hearts were not >7% higher compared to HCV-negative hearts. Willingness to accept HCV-viremic hearts for transplantation into HCV-negative recipients is cost effective and improves clinical outcomes.

The cost-effectiveness of case-finding strategies for achieving hepatitis C elimination among men who have sex with men in the UK.

Modelling suggests hepatitis C virus (HCV) elimination is possible among men who have sex with men (MSM), with key screening groups including HIV-diagnosed MSM and MSM using pre-exposure prophylaxis (PrEP). Mathematical modelling was used to determine the cost-effectiveness of HCV case-finding strategies among MSM from the provider perspective, and to determine which interventions could achieve a 90% reduction in HCV incidence over 2015-2030. At baseline, we assumed symptomatic screening in HIV-negative MSM (including PrEP users) and 12-monthly screening among HIV-diagnosed MSM. Improved case-finding strategies included screening alongside HIV testing in HIV-negative MSM not using PrEP (PrEP non-users); 12/6/3-monthly screening in PrEP users; and 6-monthly screening in HIV-diagnosed MSM, with the cost-effectiveness being compared incrementally. Costs (GBP) and quality-adjusted life years (QALYs) were assessed to estimate the mean incremental cost-effectiveness ratio (ICER) with a time horizon to 2050, compared to a willingness-to-pay threshold of £20,000/QALY. From the baseline, the most incrementally cost-effective strategy is to firstly undertake: (1) 12-monthly HCV screening of PrEP users (gaining 6715 QALYs with ICER £1760/QALY), followed by (2) HCV screening among PrEP non-users alongside HIV testing (gaining 7048 QALYs with ICER £4972/QALY). Compared to the baseline, this combined strategy would cost £46.9 (95%CrI £25.3-£66.9) million and achieve the HCV elimination target in 100% of model runs. Additional screening incurs ICERs >£20,000/QALY compared to this combined strategy. In conclusion, HCV elimination can be achieved cost-effectively among UK MSM. Policymakers should consider scaling-up HCV screening in HIV-negative MSM, especially PrEP users, for achieving this target.

Overlapping Key Populations and HIV Transmission in Tijuana, Mexico: A Modelling Analysis of Epidemic Drivers.

Tijuana, Mexico, has a concentrated HIV epidemic among overlapping key populations (KPs) including people who inject drugs (PWID), female sex workers (FSW), their male clients, and men who have sex with men (MSM). We developed a dynamic HIV transmission model among these KPs to determine the extent to which their unmet prevention and treatment needs is driving HIV transmission. Over 2020-2029 we estimated the proportion of new infections acquired in each KP, and the proportion due to their unprotected risk behaviours. We estimate that 43.7% and 55.3% of new infections are among MSM and PWID, respectively, with FSW and their clients making-up < 10% of new infections. Projections suggest 93.8% of new infections over 2020-2029 will be due to unprotected sex between MSM or unsafe injecting drug use. Prioritizing interventions addressing sexual and injecting risks among MSM and PWID are critical to controlling HIV in Tijuana.

RESUMEN: Tijuana, México, tiene una epidemia de VIH concentrada en poblaciones claves (PC) superpuestas que incluyen personas que se inyectan drogas (PID), trabajadoras sexuales (MTS), sus clientes hombres, y hombres que tienen sexo con hombres (HSH). Desarrollamos un modelo dinámico de transmisión de VIH en estas PC para determinar hasta dónde sus necesidades no atendidas de prevención y tratamiento dirigen la transmisión del VIH. Para 2020­2029 estimamos la proporción de nuevas infecciones adquiridas en cada PC, y la proporción atribuida a sus comportamientos de riesgo sin protección. Estimamos que 43.7% y 55.3% de nuevas infecciones se dan en HSH y PID, respectivamente, con MTS y clientes conformando < 10% de nuevas infecciones. Las proyecciones sugieren que 93.8% de nuevas infecciones en 2020­2029 se deberán a sexo sin protección en HSH o uso inseguro de drogas inyectables. Dar prioridad a intervenciones que atienden los riesgos sexual y de inyección en HSH y PID es crítico para controlar el VIH en Tijuana.

What is required for achieving hepatitis C virus elimination in Singapore? A modeling study.

BACKGROUND AND AIM: The vast majority of hepatitis C virus (HCV) infection in Singapore is among those with a history of injecting drug use (IDU), yet harm reduction is not available and what is required to achieve the World Health Organization (WHO) HCV elimination targets (80% incidence reduction and 65% mortality reduction by 2030) is unknown. We model the intervention scale-up required to achieve WHO targets in Singapore. METHODS: A dynamic model of HCV transmission and progression among those with a history of IDU was calibrated to Singapore, a setting with declining IDU and no harm reduction (~11 000 people with IDU history in 2017 and 45% HCV seropositive). We projected HCV treatment scale-up from 2019 required to achieve WHO targets with varying prioritization scenarios, with/without opiate substitution therapy scale-up (to 40% among people who inject drugs [PWID]). RESULTS: We estimated 3855 (95% confidence interval: 2635-5446) chronically HCV-infected individuals with a history of IDU and 148 (87-284) incident HCV cases in Singapore in 2019. Reaching the HCV incidence target requires 272 (187-384) treatments in 2019, totaling 2444 (1683-3452) across 2019-2030. By prioritizing PWID or PWID and cirrhotics, 60% or 30% fewer treatments are required, respectively, whereas the target cannot be achieved with cirrhosis prioritization. Opiate substitution therapy scale-up reduces treatments required by 21-24%. Achieving both WHO targets requires treating 631 (359-1047) in 2019, totaling 3816 (2664-5423) across 2019-2030. CONCLUSIONS: Hepatitis C virus elimination is achievable in Singapore but even with declining IDU requires immediate treatment scale-up among PWID. Harm reduction provision reduces treatments required and provides additional benefits.

Responding to global stimulant use: challenges and opportunities.

We did a global review to synthesise data on the prevalence, harms, and interventions for stimulant use, focusing specifically on the use of cocaine and amphetamines. Modelling estimated the effect of cocaine and amphetamine use on mortality, suicidality, and blood borne virus incidence. The estimated global prevalence of cocaine use was 0·4% and amphetamine use was 0·7%, with dependence affecting 16% of people who used cocaine and 11% of those who used amphetamine. Stimulant use was associated with elevated mortality, increased incidence of HIV and hepatitis C infection, poor mental health (suicidality, psychosis, depression, and violence), and increased risk of cardiovascular events. No effective pharmacotherapies are available that reduce stimulant use, and the available psychosocial interventions (except for contingency management) had a weak overall effect. Generic approaches can address mental health and blood borne virus infection risk if better tailored to mitigate the harms associated with stimulant use. Substantial and sustained investment is needed to develop more effective interventions to reduce stimulant use.

What is needed to achieve HCV microelimination among HIV-infected populations in Andalusia, Spain: a modeling analysis.

BACKGROUND: Scale-up of hepatitis C virus (HCV) treatment for HIV/HCV coinfected individuals is occurring in Spain, the vast majority (> 85%) with a reported history of injecting drug use and a smaller population of co-infected men who have sex with men (MSM). We assess impact of recent treatment scale-up to people living with HIV (PLWH) and implications for achieving the WHO HCV incidence elimination target (80% reduction 2015-2030) among PLWH and overall in Andalusia, Spain, using dynamic modeling. METHODS: A dynamic transmission model of HCV/HIV coinfection was developed. The model was stratified by people who inject drugs (PWID) and MSM. The PWID component included dynamic HCV transmission from the HCV-monoinfected population. The model was calibrated to Andalusia based on published data and the HERACLES cohort (prospective cohort of HIV/HCV coinfected individuals representing > 99% coinfected individuals in care in Andalusia). From HERACLES, we incorporated HCV treatment among diagnosed PLWH of 10.5%/year from 2004 to 2014, and DAAs at 33%/year from 2015 with 94.8% SVR. We project the impact of current and scaled-up HCV treatment for PLWH on HCV prevalence and incidence among PLWH and overall. RESULTS: Current treatment rates among PLWH (scaled-up since 2015) could substantially reduce the number of diagnosed coinfected individuals (mean 76% relative reduction from 2015 to 2030), but have little impact on new diagnosed coinfections (12% relative reduction). However, DAA scale-up to PWLH in 2015 would have minimal future impact on new diagnosed coinfections (mean 9% relative decrease from 2015 to 2030). Similarly, new cases of HCV would only reduce by a mean relative 29% among all PWID and MSM due to ongoing infection/reinfection. Diagnosing/treating all PLWH annually from 2020 would increase the number of new HCV infections among PWLH by 28% and reduce the number of new HCV infections by 39% among the broader population by 2030. CONCLUSION: Targeted scale-up of HCV treatment to PLWH can dramatically reduce prevalence among this group but will likely have little impact on the annual number of newly diagnosed HIV/HCV coinfections. HCV microelimination efforts among PWLH in Andalusia and settings where a large proportion of PLWH have a history of injecting drug use will require scaled-up HCV diagnosis and treatment among PLWH and the broader population at risk.