The impact of policing and homelessness on violence experienced by women who sell sex in London: a modelling study.

Street-based sex workers experience considerable homelessness, drug use and police enforcement, making them vulnerable to violence from clients and other perpetrators. We used a deterministic compartmental model of street-based sex workers in London to estimate whether displacement by police and unstable housing/homelessness increases client violence. The model was parameterized and calibrated using data from a cohort study of sex workers, to the baseline percentage homeless (64%), experiencing recent client violence (72%), or recent displacement (78%), and the odds ratios of experiencing violence if homeless (1.97, 95% confidence interval 0.88-4.43) or displaced (4.79, 1.99-12.11), or of experiencing displacement if homeless (3.60, 1.59-8.17). Ending homelessness and police displacement reduces violence by 67% (95% credible interval 53-81%). The effects are non-linear; halving the rate of policing or becoming homeless reduces violence by 5.7% (3.5-10.3%) or 6.7% (3.7-10.2%), respectively. Modelled interventions have small impact with violence reducing by: 5.1% (2.1-11.4%) if the rate of becoming housed increases from 1.4 to 3.2 per person-year (Housing First initiative); 3.9% (2.4-6.9%) if the rate of policing reduces by 39% (level if recent increases had not occurred); and 10.2% (5.9-19.6%) in combination. Violence reduces by 26.5% (22.6-28.2%) if half of housed sex workers transition to indoor sex work. If homelessness decreased and policing increased as occurred during the COVID-19 pandemic in 2020, the impact on violence is negligible, decreasing by 0.7% (8.7% decrease-4.1% increase). Increasing housing and reducing policing among street-based sex workers could substantially reduce violence, but large changes are needed.

Mitigation through on-site testing & education among formerly incarcerated individuals against Covid-19 - The MOSAIC study: Design and rationale.

BACKGROUND: Many of the largest COVID-19 outbreaks in the United States have occurred at carceral facilities. Criminal legal system (CLS)-involved individuals typically face structural barriers accessing medical care post-release. Improving COVID-19 testing and education for CLS-involved individuals could improve health outcomes for this vulnerable population and the communities to which they return. Community-based organizations (CBO) and community health workers (CHWs) fill care gaps by connecting CLS-involved individuals with essential re-entry services. The MOSAIC study will: 1) test an onsite CHW-led SARS-CoV-2 testing and education intervention in a reentry CBO and 2) model the cost-effectiveness of this intervention compared to standard care. METHODS: We will recruit 250 CLS-involved individuals who have left incarceration in the prior 90 days. Participants will be randomized to receive onsite Point-of-Care testing and education (O-PoC) or Standard of Care (SoC). Over one year, participants will complete quarterly questionnaires and biweekly short surveys through a mobile application, and be tested for SARS-CoV-2 quarterly, either at the CBO (O-PoC) or an offsite community testing site (SoC). O-PoC will also receive COVID-19 mitigation counseling and education from the CHW. Our primary outcome is the proportion of SARS-CoV-2 tests performed with results received by participants. Secondary outcomes include adherence to mitigation behaviors and cost-effectiveness of the intervention. DISCUSSION: The MOSAIC study will offer insight into cost effective strategies for SARS-CoV-2 testing and education for CLS-involved individuals. The study will also contribute to the growing literature on CHW's role in health education, supportive counseling, and building trust between patients and healthcare organizations.

Costs of syringe vending machines in Tbilisi, Georgia.

BACKGROUND: Syringe vending machines (SVM) can improve access to sterile injecting equipment, but they have not been widely implemented or evaluated. We evaluate the cost of SVM installed between July 2019-December 2020 in Tbilisi, Georgia. METHODS: The SVM were stocked with several kit types, including injecting equipment for opioid or stimulant users, naloxone, male and female condoms, and pregnancy tests. We gathered financial data from the project to estimate fixed (staff time, start-up costs, equipment, running costs, and consumables) and variable (harm reduction kits) costs. We calculated the full cost of the SVM intervention, cost per user, cost per additional syringe accessed by SVM users, and cost per kit distributed (2020 Euros). RESULTS: SVM access cards were issued to 1132 users, and 29,238 kits were distributed through SVM, total cost €204,358. Staff costs were 51% of total, consumable costs 28%, equipment 10%, and start up, recurrent costs, and overheads 5% or less each. Opioid and stimulant kits were most accessed (35% and 32% of total). Cost per user was €66/year, and cost per transaction €7, of which €5 fixed costs and €2 variable. If monthly transactions increased from the average of 1622/month to highest monthly usage (4714), fixed costs per transaction would decrease to < €1. It cost €0.55 per additional syringe accessed/user/month. CONCLUSIONS: This study provides evidence for governments about the cost of SVM, a novel harm reduction intervention. This is particularly relevant where Global Fund is withdrawing and harm reduction services need to be incorporated into national budgets.

Estimates of hepatitis B virus prevalence among general population and key risk groups in EU/EEA/UK countries: a systematic review.

BackgroundThe burden of chronic hepatitis B virus (HBV) varies across the European Union (EU) and European Economic Area (EEA).AimWe aimed to update the 2017 HBV prevalence estimates in EU/EEA countries and the United Kingdom for 2018 to 2021.MethodsWe undertook a systematic review, adding to HBV prevalence estimates from an existing (2005-2017) database. Databases were searched for original English-language research articles including HBV surface antigen prevalence estimates among the general population, pregnant women, first-time blood donors (FTB), men who have sex with men (MSM), migrants and people in prison. Country experts contributed grey literature data. Risk of bias was assessed using a quality assessment framework.FindingsThe update provided 147 new prevalence estimates across the region (updated total n = 579). Median HBV prevalence in the general population was 0.5% and the highest was 3.8% (Greece). Among FTB, the highest prevalence was 0.8% (Lithuania). Estimates among pregnant women were highest in Romania and Italy (5.1%). Among migrants, the highest estimate was 31.7% (Spain). Relative to 2017 estimates, median prevalence among pregnant women decreased by 0.5% (to 0.3%) and increased by 0.9% (to 5.8%) among migrants. Among MSM, the highest estimate was 3.4% (Croatia). Prevalence among people in prison was highest in Greece (8.3%) and the median prevalence increased by 0.6% (to 2.1%).ConclusionsThe HBV prevalence is low in the general population and confined to risk populations in most European countries with some exceptions. Screening and treatment should be targeted to people in prison and migrants.

Insights from a national survey in 2021 and from modelling on progress towards hepatitis C virus elimination in the country of Georgia since 2015.

BackgroundBetween May 2015 and February 2022, 77,168 hepatitis C virus (HCV)-infected people in Georgia have been treated through an HCV elimination programme. To project the programme's long-term impacts, an HCV infection model was initially developed, based on data from surveys among people who inject drugs and a national serosurvey in 2015.AimAccounting for follow-up surveys in 2021, we validate and update projections of HCV infection prevalence and incidence.MethodWe assessed the initial model projections' accuracy for overall prevalence, by age, sex, and among people who ever injected drugs, compared with 2021 serosurvey data. We used 2021 results to weight model fits and to recalculate the national programme's impact leading up to March 2022 on HCV infection incidence rates. Cases and deaths averted were estimated. The impact of reduced treatment rates during the COVID-19 pandemic was assessed.ResultsThe original model overpredicted adult (≥ 18 years old) chronic HCV infection prevalence for 2021 (2.7%; 95% credible interval (CrI): 1.9-3.5%) compared with a 2021 serosurvey (1.8%; 95% confidence interval (CI): 1.3-2.4%). Weighted model projections estimated a 60% decrease in HCV infection incidence by March 2022, with an absolute incidence of 66 (95% CrI: 34-131) per 100,000 person-years (overall population). Between May 2015 and March 2022, 9,186 (95% CrI: 5,396-16,720) infections and 842 (95% CrI: 489-1,324) deaths were averted. The COVID-19 pandemic resulted in 13,344 (95% CrI: 13,236-13,437) fewer treatments and 438 (95% CrI: 223-744) fewer averted infections by March 2022.ConclusionResults support the programme's high effectiveness. At current treatment rate (406/month), 90% reductions in prevalence and incidence in Georgia are achievable by 2030.

Estimating hepatitis B virus prevalence among key population groups for European Union and European Economic Area countries and the United Kingdom: a modelling study.

BACKGROUND: Hepatitis B virus (HBV) epidemiology in Europe differs by region and population risk group, and data are often incomplete. We estimated chronic HBV prevalence as measured by surface antigen (HBsAg) among general and key population groups for each country in the European Union, European Economic Area and the United Kingdom (EU/EEA/UK), including where data are currently unavailable. METHODS: We combined data from a 2018 systematic review (updated in 2021), data gathered directly by the European Centre for Disease Control (ECDC) from EU/EEA countries and the UK and further country-level data. We included data on adults from the general population, pregnant women, first time blood donors (FTBD), men who have sex with men (MSM), prisoners, people who inject drugs (PWID), and migrants from 2001 to 2021, with three exceptions made for pre-2001 estimates. Finite Mixture Models (FMM) and Beta regression were used to predict country and population group HBsAg prevalence. A separate multiplier method was used to estimate HBsAg prevalence among the migrant populations within each country, due to biases in the data available. RESULTS: There were 595 included studies from 31 countries (N = 41,955,969 people): 66 were among the general population (mean prevalence ([Formula: see text]) 1.3% [range: 0.0-7.6%]), 52 among pregnant women ([Formula: see text]1.1% [0.1-5.3%]), 315 among FTBD ([Formula: see text]0.3% [0.0-6.2%]), 20 among MSM ([Formula: see text]1.7% [0.0-11.2%]), 34 among PWID ([Formula: see text]3.9% [0.0-16.9%]), 24 among prisoners ([Formula: see text]2.9% [0.0-10.7%]), and 84 among migrants ([Formula: see text]7.0% [0.2-37.3%]). The FMM grouped countries into 3 classes. We estimated HBsAg prevalence among the general population to be < 1% in 24/31 countries, although it was higher in 7 Eastern/Southern European countries. HBsAg prevalence among each population group was higher in most Eastern/Southern European than Western/Northern European countries, whilst prevalence among PWID and prisoners was estimated at > 1% for most countries. Portugal had the highest estimated prevalence of HBsAg among migrants (5.0%), with the other highest prevalences mostly seen in Southern Europe. CONCLUSIONS: We estimated HBV prevalence for each population group within each EU/EAA country and the UK, with general population HBV prevalence to be < 1% in most countries. Further evidence is required on the HBsAg prevalence of high-risk populations for future evidence synthesis.

Cost-effectiveness of Hepatitis C virus self-testing in four settings.

Globally, there are approximately 58 million people with chronic hepatitis C virus infection (HCV) but only 20% have been diagnosed. HCV self-testing (HCVST) could reach those who have never been tested and increase uptake of HCV testing services. We compared cost per HCV viraemic diagnosis or cure for HCVST versus facility-based HCV testing services. We used a decision analysis model with a one-year time horizon to examine the key drivers of economic cost per diagnosis or cure following the introduction of HCVST in China (men who have sex with men), Georgia (men 40-49 years), Viet Nam (people who inject drugs, PWID), and Kenya (PWID). HCV antibody (HCVAb) prevalence ranged from 1%-60% across settings. Model parameters in each setting were informed by HCV testing and treatment programmes, HIV self-testing programmes, and expert opinion. In the base case, we assume a reactive HCVST is followed by a facility-based rapid diagnostic test (RDT) and then nucleic acid testing (NAT). We assumed oral-fluid HCVST costs of $5.63/unit ($0.87-$21.43 for facility-based RDT), 62% increase in testing following HCVST introduction, 65% linkage following HCVST, and 10% replacement of facility-based testing with HCVST based on HIV studies. Parameters were varied in sensitivity analysis. Cost per HCV viraemic diagnosis without HCVST ranged from $35 2019 US dollars (Viet Nam) to $361 (Kenya). With HCVST, diagnosis increased resulting in incremental cost per diagnosis of $104 in Viet Nam, $163 in Georgia, $587 in Kenya, and $2,647 in China. Differences were driven by HCVAb prevalence. Switching to blood-based HCVST ($2.25/test), increasing uptake of HCVST and linkage to facility-based care and NAT testing, or proceeding directly to NAT testing following HCVST, reduced the cost per diagnosis. The baseline incremental cost per cure was lowest in Georgia ($1,418), similar in Viet Nam ($2,033), and Kenya ($2,566), and highest in China ($4,956). HCVST increased the number of people tested, diagnosed, and cured, but at higher cost. Introducing HCVST is more cost-effective in populations with high prevalence.

Modelling the impact and cost-effectiveness of non-governmental organizations on HIV and HCV transmission among people who inject drugs in Ukraine.

INTRODUCTION: People who inject drugs (PWID) in Ukraine have high prevalences of HIV and hepatitis C virus (HCV). Non-governmental organizations (NGOs) provide PWID with needles/syringes, condoms, HIV/HCV testing and linkage to opioid agonist treatment (OAT) and antiretroviral therapy (ART). We estimated their impact and cost-effectiveness among PWID. METHODS: A dynamic HIV and HCV transmission model among PWID was calibrated using data from four national PWID surveys (2011-2017). The model assumed 37-49% coverage of NGOs among community PWID, with NGO contact reducing injecting risk and increasing condom use and recruitment onto OAT and ART. We estimated the historic (1997-2021) and future (2022-2030, compared to no NGO activities from 2022) impact of NGOs in terms of the proportion of HIV/HCV infections averted and changes in HIV/HCV incidence. We estimated the future impact of scaling-up NGOs to 80% coverage with/without scale-up in OAT (5-20%) and ART (64-81%). We estimated the cost per disability-adjusted life-year (DALY) averted of current NGO provision over 2022-2041 compared to NGO activities stopping over 2022-2026, but restarting after that till 2041. We assumed average unit costs of US$80-90 per person-year of NGO contact for PWID. RESULTS: With existing coverage levels of NGOs, the model projects that NGOs have averted 20.0% (95% credibility interval: 13.3-26.1) and 9.6% (5.1-14.1) of new HIV and HCV infections among PWID over 1997-2021, respectively, and will avert 31.8% (19.6-39.9) and 13.7% (7.5-18.1) of HIV and HCV infections over 2022-2030. With NGO scale-up, HIV and HCV incidence will decrease by 54.2% (43.3-63.8) and 30.2% (20.5-36.2) over 2022-2030, or 86.7% (82.9-89.3) and 39.8% (31.4-44.8) if OAT and ART are also scaled-up. Without NGOs, HIV and HCV incidence will increase by 51.6% (23.6-76.3) and 13.4% (4.8-21.9) over 2022-2030. Current NGO provision over 2022-2026 will avert 102,736 (77,611-137,512) DALYs when tracked until 2041 (discounted 3% annually), and cost US$912 (702-1222) per DALY averted; cost-effective at a willingness-to-pay threshold of US$1548/DALY averted (0.5xGDP). CONCLUSIONS: NGO activities have a crucial preventative impact among PWID in Ukraine which should be scaled-up to help achieve HIV and HCV elimination. Disruptions could have a substantial detrimental impact.

Incidence of HIV and hepatitis C virus among people who inject drugs, and associations with age and sex or gender: a global systematic review and meta-analysis.

BACKGROUND: Measuring the incidence of HIV and hepatitis C virus (HCV) infection among people who inject drugs (PWID) is key to track progress towards elimination. We aimed to summarise global data on HIV and primary HCV incidence among PWID and associations with age and sex or gender. METHODS: In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies among PWID by searching MEDLINE, Embase, and PsycINFO, capturing studies published between Jan 1, 2000, and Dec 12, 2022, with no language or study design restrictions. We contacted authors of identified studies for unpublished or updated data. We included studies that estimated incidence by longitudinally re-testing people at risk of infection or by using assays for recent infection. We pooled incidence and relative risk (RR; young [generally defined as ≤25 years] vs older PWID; women vs men) estimates using random-effects meta-analysis and assessed risk of bias with a modified Newcastle-Ottawa scale. This study is registered with PROSPERO, CRD42020220884. FINDINGS: Our updated search identified 9493 publications, of which 211 were eligible for full-text review. An additional 377 full-text records from our existing database and five records identified through cross-referencing were assessed. Including 28 unpublished records, 125 records met the inclusion criteria. We identified 64 estimates of HIV incidence (30 from high-income countries [HICs] and 34 from low-income or middle-income countries [LMICs]) and 66 estimates of HCV incidence (52 from HICs and 14 from LMICs). 41 (64%) of 64 HIV and 42 (64%) of 66 HCV estimates were from single cities rather than being multi-city or nationwide. Estimates were measured over 1987-2021 for HIV and 1992-2021 for HCV. Pooled HIV incidence was 1·7 per 100 person-years (95% CI 1·3-2·3; I2=98·4%) and pooled HCV incidence was 12·1 per 100 person-years (10·0-14·6; I2=97·2%). Young PWID had a greater risk of HIV (RR 1·5, 95% CI 1·2-1·8; I2=66·9%) and HCV (1·5, 1·3-1·8; I2=70·6%) acquisition than older PWID. Women had a greater risk of HIV (RR 1·4, 95% CI 1·1-1·6; I2=55·3%) and HCV (1·2, 1·1-1·3; I2=43·3%) acquisition than men. For both HIV and HCV, the median risk-of-bias score was 6 (IQR 6-7), indicating moderate risk. INTERPRETATION: Although sparse, available HIV and HCV incidence estimates offer insights into global levels of HIV and HCV transmission among PWID. Intensified efforts are needed to keep track of the HIV and HCV epidemics among PWID and to expand access to age-appropriate and gender-appropriate prevention services that serve young PWID and women who inject drugs. FUNDING: Canadian Institutes of Health Research, Fonds de recherche du Québec-Santé, Canadian Network on Hepatitis C, UK National Institute for Health and Care Research, and WHO.

Predictors of hepatitis C cure among people who inject drugs treated with directly observed therapy supported by peer case managers in Kenya.

BACKGROUND & AIMS: Directly observed therapy (DOT) maximizes adherence and minimizes treatment gaps. Peer case managers (PCM) have also shown promise as a component of integrated HCV treatment strategies. DOT and PCM-support have been underexplored, particularly in low- and middle-income countries (LMICs). The objective of this study was to evaluate predictors of sustained virologic response (SVR) among people who inject drugs (PWID) attending medication-assisted treatment (MAT) and needle and syringe programs (NSP) sites in Kenya. METHODS: We recruited PWID accessing MAT and NSP in Nairobi and Coastal Kenya. PWID were treated with ledipasvir/sofosbuvir using DOT supported by PCMs. We used bivariate and multivariate logistic regression to examine the impact of sociodemographic, behavioral, and clinical factors on SVR. RESULTS: Among 92 PWID who initiated HCV treatment, 79 (86%) were male with mean age of 36.3 years (SD=±6.5); 38 (41%) were HIV-positive, and 87 (95%) reported injecting drugs in the last 30 days. Just over half of participants were genotype 1a (55%), followed by genotype 4a (41%) and mixed 1a/4a (3%). Most participants, 85 (92%) completed treatment and 79 (86%) achieved SVR. While sociodemographic and behavioral factors including recent injection drug use were not significantly associated with achieving SVR, being fully adherent (p=0.042), number of doses taken (p=0.008) and treatment completion (p= 0.001) were associated with higher odds of achieving SVR. CONCLUSIONS: DOT with PCM-support was an effective model for HCV treatment among PWID in this LMIC setting. Adherence was the most important driver of SVR suggesting DOT and PCM support can overcome other factors that might limit adherence. Further research is necessary to ascertain the effectiveness of other models of HCV care for PWID in LMICs given NSP and MAT access is variable, and DOT may not be sustainable with limited resources.

Economic evaluation of the Hepatitis C virus elimination program in the country of Georgia, 2015 to 2017.

BACKGROUND AND AIMS: In 2015, the country of Georgia launched an elimination program aiming to reduce the prevalence of Hepatitis C virus (HCV) infection by 90% from 5.4% prevalence (~150 000 people). During the first 2.5 years of the program, 770 832 people were screened, 48 575 were diagnosed with active HCV infection, and 41 483 patients were treated with direct-acting antiviral (DAA)-based regimens, with a >95% cure rate. METHODS: We modelled the incremental cost-effectiveness ratio (ICER) of HCV screening, diagnosis and treatment between April 2015 and November 2017 compared to no treatment, in terms of cost per quality-adjusted life year (QALY) gained in 2017 US dollars, with a 3% discount rate over 25 years. We compared the ICER to willingness-to-pay (WTP) thresholds of US$4357 (GDP) and US$871 (opportunity cost) per QALY gained. RESULTS: The average cost of screening, HCV viremia testing, and treatment per patient treated was $386 to the provider, $225 to the patient and $1042 for generic DAAs. At 3% discount, 0.57 QALYs were gained per patient treated. The ICER from the perspective of the provider including generic DAAs was $2285 per QALY gained, which is cost-effective at the $4357 WTP threshold, while if patient costs are included, it is just above the threshold at $4398/QALY. All other scenarios examined in sensitivity analyses remain cost-effective except for assuming a shorter time horizon to the end of 2025 or including the list price DAA cost. Reducing or excluding DAA costs reduced the ICER below the opportunity-cost WTP threshold. CONCLUSIONS: The Georgian HCV elimination program provides valuable evidence that national programs for scaling up HCV screening and treatment for achieving HCV elimination can be cost-effective.

Impact and cost-effectiveness of non-governmental organizations on the HIV epidemic in Ukraine among MSM.

OBJECTIVE: Non-governmental organizations (NGOs) in Ukraine have provided HIV testing, treatment, and condom distribution for MSM. HIV prevalence among MSM in Ukraine is 5.6%. We estimated the impact and cost-effectiveness of MSM-targeted NGO activities in Ukraine. DESIGN: A mathematical model of HIV transmission among MSM was calibrated to data from Ukraine (2011-2018). METHODS: The model, designed before the 2022 Russian invasion of Ukraine, evaluated the impact of 2018 status quo coverage levels of 28% of MSM being NGO clients over 2016-2020 and 2021-2030 compared with no NGO activities over these time periods. Impact was measured in HIV incidence and infections averted. We compared the costs and disability adjusted life years (DALYs) for the status quo and a counterfactual scenario (no NGOs 2016-2020, but with NGOs thereafter) until 2030 to estimate the mean incremental cost-effectiveness ratio (cost per DALY averted). RESULTS: Without NGO activity over 2016-2020, the HIV incidence in 2021 would have been 44% (95% credibility interval: 36-59%) higher than with status quo levels of NGO activity, with 25% (21-30%) more incident infections occurring over 2016-2020. Continuing with status quo NGO coverage levels will decrease HIV incidence by 41% over 2021-2030, whereas it will increase by 79% (60-120%) with no NGOs over this period and 37% (30-51%) more HIV infections will occur. Compared with if NGO activities had ceased over 2016-2020 (but continued thereafter), the status quo scenario averts 14 918 DALYs over 2016-2030 with a mean incremental cost-effectiveness ratio of US$600.15 per DALY averted. CONCLUSION: MSM-targeted NGOs in Ukraine have prevented considerable HIV infections and are highly cost-effective compared with a willingness-to-pay threshold of 50% of Ukraine's 2018 GDP (US$1548).

Modelling the impact of HIV and hepatitis C virus prevention and treatment interventions among people who inject drugs in Kenya.

OBJECTIVES: People who inject drugs (PWID) in Kenya have high HIV (range across settings: 14-26%) and hepatitis C virus (HCV; 11-36%) prevalence. We evaluated the impact of existing and scaled-up interventions on HIV and HCV incidence among PWID in Kenya. DESIGN: HIV and HCV transmission model among PWID, calibrated to Nairobi and Kenya's Coastal region. METHODS: For each setting, we projected the impact (percent of HIV/HCV infections averted in 2020) of existing coverages of antiretroviral therapy (ART; 63-79%), opioid agonist therapy (OAT; 8-13%) and needle and syringe programmes (NSP; 45-61%). We then projected the impact (reduction in HIV/HCV incidence over 2021-2030), of scaling-up harm reduction [Full harm reduction ('Full HR'): 50% OAT, 75% NSP] and/or HIV (UNAIDS 90-90-90) and HCV treatment (1000 PWID over 2021-2025) and reducing sexual risk (by 25/50/75%). We estimated HCV treatment levels needed to reduce HCV incidence by 90% by 2030. RESULTS: In 2020, OAT and NSP averted 46.0-50.8% (range of medians) of HIV infections and 50.0-66.1% of HCV infections, mostly because of NSP. ART only averted 12.9-39.8% of HIV infections because of suboptimal viral suppression (28-48%). Full HR and ART could reduce HIV incidence by 51.5-64% and HCV incidence by 84.6-86.6% by 2030. Also halving sexual risk could reduce HIV incidence by 68.0-74.1%. Alongside full HR, treating 2244 PWID over 2021-2025 could reduce HCV incidence by 90% by 2030. CONCLUSION: Existing interventions are having substantial impact on HIV and HCV transmission in Kenya. However, to eliminate HIV and HCV, further scale-up is needed with reductions in sexual risk and HCV treatment.

Methods and indicators to validate country reductions in incidence of hepatitis C virus infection to elimination levels set by WHO.

One of the main goals of the 2016 Global Health Sector Strategy on viral hepatitis is the elimination of hepatitis C virus (HCV) as a public health problem by 2030, defined as an 80% reduction in incidence and 65% reduction in mortality relative to 2015. Although monitoring HCV incidence is key to validating HCV elimination, use of the gold-standard method, which involves prospective HCV retesting of people at risk, can be prohibitively resource-intensive. Additionally, few countries collected quality data in 2015 to enable an 80% decrease by 2030 to be calculated. Here, we first review different methods of monitoring HCV incidence and discuss their resource implications and applicability to various populations. Second, using mathematical models developed for various global settings, we assess whether trends in HCV chronic prevalence or HCV antibody prevalence or scale-up levels for HCV testing, treatment, and preventative interventions can be used as reliable alternative indicators to validate the HCV incidence target. Third, we discuss the advantages and disadvantages of an absolute HCV incidence target and suggest a suitable threshold. Finally, we propose three options that countries can use to validate the HCV incidence target, depending on the available surveillance infrastructure.

Health and economic benefits of achieving hepatitis C virus elimination in Pakistan: A modelling study and economic analysis.

BACKGROUND: Modelling suggests that achieving the WHO incidence target for hepatitis C virus (HCV) elimination in Pakistan could cost US$3.87 billion over 2018 to 2030. However, the economic benefits from integrating services or improving productivity were not included. METHODS AND FINDINGS: We adapt a HCV transmission model for Pakistan to estimate the impact, costs, and cost-effectiveness of achieving HCV elimination (reducing annual HCV incidence by 80% by 2030) with stand-alone service delivery, or partially integrating one-third of initial HCV testing into existing healthcare services. We estimate the net economic benefits by comparing the required investment in screening, treatment, and healthcare management to the economic productivity gains from reduced HCV-attributable absenteeism, presenteeism, and premature deaths. We also calculate the incremental cost-effectiveness ratio (ICER) per disability-adjusted life year (DALY) averted for HCV elimination versus maintaining current levels of HCV treatment. This is compared to an opportunity cost-based willingness-to-pay threshold for Pakistan (US$148 to US$198/DALY). Compared to existing levels of treatment, scaling up screening and treatment to achieve HCV elimination in Pakistan averts 5.57 (95% uncertainty interval (UI) 3.80 to 8.22) million DALYs and 333,000 (219,000 to 509,000) HCV-related deaths over 2018 to 2030. If HCV testing is partially integrated, this scale-up requires an investment of US$1.45 (1.32 to 1.60) billion but will result in US$1.30 (0.94 to 1.72) billion in improved economic productivity over 2018 to 2030. This elimination strategy is highly cost-effective (ICER = US$29 per DALY averted) by 2030, with it becoming cost-saving by 2031 and having a net economic benefit of US$9.10 (95% UI 6.54 to 11.99) billion by 2050. Limitations include uncertainty around what level of integration is possible within existing primary healthcare services as well as a lack of Pakistan-specific data on disease-related healthcare management costs or productivity losses due to HCV. CONCLUSIONS: Investment in HCV elimination can bring about substantial societal health and economic benefits for Pakistan.

Modelling the impact of HIV and HCV prevention and treatment interventions for people who inject drugs in Dar es Salaam, Tanzania.

INTRODUCTION: People who inject drugs (PWID) in Dar es Salaam, Tanzania, have a high prevalence of HIV and hepatitis C virus (HCV). While needle and syringe programmes (NSP), opioid agonist therapy (OAT) and anti-retroviral therapy (ART) are available in Tanzania, their coverage is sub-optimal. We assess the impact of existing and scaled up harm reduction (HR) interventions on HIV and HCV transmission among PWID in Dar es Salaam. METHODS: An HIV and HCV transmission model among PWID in Tanzania was calibrated to data over 2006-2018 on HIV (∼30% and ∼67% prevalence in males and females in 2011) and HCV prevalence (∼16% in 2017), numbers on HR interventions (5254 ever on OAT in 2018, 766-1479 accessing NSP in 2017) and ART coverage (63.1% in 2015). We evaluated the impact of existing interventions in 2019 and impact by 2030 of scaling-up the coverage of OAT (to 50% of PWID), NSP (75%, both combined termed "full HR") and ART (81% with 90% virally suppressed) from 2019, reducing sexual HIV transmission by 50%, and/or HCV-treating 10% of PWID infected with HCV annually. RESULTS: The model projects HIV and HCV prevalence of 19.0% (95% credibility interval: 16.4-21.2%) and 41.0% (24.4-49.0%) in 2019, respectively. For HIV, 24.6% (13.6-32.6%) and 70.3% (59.3-77.1%) of incident infections among male and female PWID are sexually transmitted, respectively. Due to their low coverage (22.8% for OAT, 16.3% for NSP in 2019), OAT and NSP averted 20.4% (12.9-24.7%) of HIV infections and 21.7% (17.0-25.2%) of HCV infections in 2019. Existing ART (68.5% coverage by 2019) averted 48.1% (29.7-64.3%) of HIV infections in 2019. Scaling up to full HR will reduce HIV and HCV incidence by 62.6% (52.5-74.0%) and 81.4% (56.7-81.4%), respectively, over 2019-2030; scaled up ART alongside full HR will decrease HIV incidence by 66.8% (55.6-77.5%), increasing to 81.5% (73.7-87.5%) when sexual risk is also reduced. HCV-treatment alongside full HR will decrease HCV incidence by 92.4% (80.7-95.8%) by 2030. CONCLUSIONS: Combination interventions, including sexual risk reduction and HCV treatment, are needed to eliminate HCV and HIV among PWID in Tanzania.

Contacts and behaviours of university students during the COVID-19 pandemic at the start of the 2020/2021 academic year.

University students have unique living, learning and social arrangements which may have implications for infectious disease transmission. To address this data gap, we created CONQUEST (COroNavirus QUESTionnaire), a longitudinal online survey of contacts, behaviour, and COVID-19 symptoms for University of Bristol (UoB) staff/students. Here, we analyse results from 740 students providing 1261 unique records from the start of the 2020/2021 academic year (14/09/2020-01/11/2020), where COVID-19 outbreaks led to the self-isolation of all students in some halls of residences. Although most students reported lower daily contacts than in pre-COVID-19 studies, there was heterogeneity, with some reporting many (median = 2, mean = 6.1, standard deviation = 15.0; 8% had ≥ 20 contacts). Around 40% of students' contacts were with individuals external to the university, indicating potential for transmission to non-students/staff. Only 61% of those reporting cardinal symptoms in the past week self-isolated, although 99% with a positive COVID-19 test during the 2 weeks before survey completion had self-isolated within the last week. Some students who self-isolated had many contacts (mean = 4.3, standard deviation = 10.6). Our results provide context to the COVID-19 outbreaks seen in universities and are available for modelling future outbreaks and informing policy.

Homelessness, unstable housing, and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis.

BACKGROUND: People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed. METHODS: In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I2 statistic and p value for heterogeneity. FINDINGS: We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23-1·95; p=0·0002]; I2= 62·7%; n=17) and HCV (1·65 [1·44-1·90; p<0·0001]; I2= 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06-1·84; p=0·019]; I2= 65·5%; n=9; and for HCV: 1·64 [1·43-1·89; p<0·0001]; I2= 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13-2·95; p=0·014]; n=5) was higher than for homelessness (1·44 [1·13-1·83; p=0·0036]; n=12), whereas no difference was seen between these outcomes for risk of HCV acquisition (1·72 [1·48-1·99; p<0·0001] for unstable housing, 1·66 [1·37-2·00; p<0·0001] for homelessness). INTERPRETATION: Homelessness and unstable housing are associated with increased risk of HIV and HCV acquisition among PWID. Our findings support the development of interventions that simultaneously address homelessness and unstable housing and HIV and HCV transmission in this population. FUNDING: National Institute for Health Research, National Institute on Drug Abuse, National Institute of Allergy and Infectious Diseases, and Commonwealth Scholarship Commission.