Kentucky Outreach Service Kiosk (KyOSK) Study protocol: a community-level, controlled quasi-experimental, type 1 hybrid effectiveness study to assess implementation, effectiveness and cost-effectiveness of a community-tailored harm reduction kiosk on HIV, HCV and overdose risk in rural Appalachia.

INTRODUCTION: Many rural communities bear a disproportionate share of drug-related harms. Innovative harm reduction service models, such as vending machines or kiosks, can expand access to services that reduce drug-related harms. However, few kiosks operate in the USA, and their implementation, impact and cost-effectiveness have not been adequately evaluated in rural settings. This paper describes the Kentucky Outreach Service Kiosk (KyOSK) Study protocol to test the effectiveness, implementation outcomes and cost-effectiveness of a community-tailored, harm reduction kiosk in reducing HIV, hepatitis C and overdose risk in rural Appalachia. METHODS AND ANALYSIS: KyOSK is a community-level, controlled quasi-experimental, non-randomised trial. KyOSK involves two cohorts of people who use drugs, one in an intervention county (n=425) and one in a control county (n=325). People who are 18 years or older, are community-dwelling residents in the target counties and have used drugs to get high in the past 6 months are eligible. The trial compares the effectiveness of a fixed-site, staffed syringe service programme (standard of care) with the standard of care supplemented with a kiosk. The kiosk will contain various harm reduction supplies accessible to participants upon valid code entry, allowing dispensing data to be linked to participant survey data. The kiosk will include a call-back feature that allows participants to select needed services and receive linkage-to-care services from a peer recovery coach. The cohorts complete follow-up surveys every 6 months for 36 months (three preceding kiosk implementation and four post-implementation). The study will test the effectiveness of the kiosk on reducing risk behaviours associated with overdose, HIV and hepatitis C, as well as implementation outcomes and cost-effectiveness. ETHICS AND DISSEMINATION: The University of Kentucky Institutional Review Board approved the protocol. Results will be disseminated in academic conferences and peer-reviewed journals, online and print media, and community meetings. TRIAL REGISTRATION NUMBER: NCT05657106.

Scale-up of Direct-Acting Antiviral Treatment in Prisons Is Both Cost-effective and Key to Hepatitis C Virus Elimination.

Background: The Surveillance and Treatment of Prisoners With Hepatitis C (SToP-C) study demonstrated that scaling up of direct-acting antiviral (DAA) treatment reduced hepatitis C virus (HCV) transmission. We evaluated the cost-effectiveness of scaling up HCV treatment in statewide prison services incorporating long-term outcomes across custodial and community settings. Methods: A dynamic model of incarceration and HCV transmission among people who inject drugs (PWID) in New South Wales, Australia, was extended to include former PWID and those with long-term HCV progression. Using Australian costing data, we estimated the cost-effectiveness of scaling up HCV treatment in prisons by 44% (as achieved by the SToP-C study) for 10 years (2021-2030) before reducing to baseline levels, compared to a status quo scenario. The mean incremental cost-effectiveness ratio (ICER) was estimated by comparing the differences in costs and quality-adjusted life-years (QALYs) between the scale-up and status quo scenarios over 40 years (2021-2060) discounted at 5% per annum. Univariate and probabilistic sensitivity analyses were performed. Results: Scaling up HCV treatment in the statewide prison service is projected to be cost-effective with a mean ICER of A$12 968/QALY gained. The base-case scenario gains 275 QALYs over 40 years at a net incremental cost of A$3.6 million. Excluding DAA pharmaceutical costs, the mean ICER is reduced to A$6 054/QALY. At the willingness-to-pay threshold of A$50 000/QALY, 100% of simulations are cost-effective at various discount rates, time horizons, and changes of treatment levels in prison and community. Conclusions: Scaling up HCV testing and treatment in prisons is highly cost-effective and should be considered a priority in the national elimination strategy. Clinical Trials Registration: NCT02064049.

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.

Impact and cost-effectiveness of the national scale-up of HIV pre-exposure prophylaxis among female sex workers in South Africa: a modelling analysis.

INTRODUCTION: In 2016, South Africa (SA) initiated a national programme to scale-up pre-exposure prophylaxis (PrEP) among female sex workers (FSWs), with ∼20,000 PrEP initiations among FSWs (∼14% of FSW) by 2020. We evaluated the impact and cost-effectiveness of this programme, including future scale-up scenarios and the potential detrimental impact of the COVID-19 pandemic. METHODS: A compartmental HIV transmission model for SA was adapted to include PrEP. Using estimates on self-reported PrEP adherence from a national study of FSW (67.7%) and the Treatment and Prevention for FSWs (TAPS) PrEP demonstration study in SA (80.8%), we down-adjusted TAPS estimates for the proportion of FSWs with detectable drug levels (adjusted range: 38.0-70.4%). The model stratified FSW by low (undetectable drug; 0% efficacy) and high adherence (detectable drug; 79.9%; 95% CI: 67.2-87.6% efficacy). FSWs can transition between adherence levels, with lower loss-to-follow-up among highly adherent FSWs (aHR: 0.58; 95% CI: 0.40-0.85; TAPS data). The model was calibrated to monthly data on the national scale-up of PrEP among FSWs over 2016-2020, including reductions in PrEP initiations during 2020. The model projected the impact of the current programme (2016-2020) and the future impact (2021-2040) at current coverage or if initiation and/or retention are doubled. Using published cost data, we assessed the cost-effectiveness (healthcare provider perspective; 3% discount rate; time horizon 2016-2040) of the current PrEP provision. RESULTS: Calibrated to national data, model projections suggest that 2.1% of HIV-negative FSWs were currently on PrEP in 2020, with PrEP preventing 0.45% (95% credibility interval, 0.35-0.57%) of HIV infections among FSWs over 2016-2020 or 605 (444-840) infections overall. Reductions in PrEP initiations in 2020 possibly reduced infections averted by 18.57% (13.99-23.29). PrEP is cost-saving, with $1.42 (1.03-1.99) of ART costs saved per dollar spent on PrEP. Going forward, existing coverage of PrEP will avert 5,635 (3,572-9,036) infections by 2040. However, if PrEP initiation and retention doubles, then PrEP coverage increases to 9.9% (8.7-11.6%) and impact increases 4.3 times with 24,114 (15,308-38,107) infections averted by 2040. CONCLUSIONS: Our findings advocate for the expansion of PrEP to FSWs throughout SA to maximize its impact. This should include strategies to optimize retention and should target women in contact with FSW services.

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).

An intensive model of care for hepatitis C virus screening and treatment with direct-acting antivirals in people who inject drugs in Nairobi, Kenya: a model-based cost-effectiveness analysis.

BACKGROUND AND AIMS: Hepatitis C virus (HCV) treatment is essential for eliminating HCV in people who inject drugs (PWID), but has limited coverage in resource-limited settings. We measured the cost-effectiveness of a pilot HCV screening and treatment intervention using directly observed therapy among PWID attending harm reduction services in Nairobi, Kenya. DESIGN: We utilized an existing model of HIV and HCV transmission among current and former PWID in Nairobi to estimate the cost-effectiveness of screening and treatment for HCV, including prevention benefits versus no screening and treatment. The cure rate of treatment and costs for screening and treatment were estimated from intervention data, while other model parameters were derived from literature. Cost-effectiveness was evaluated over a life-time horizon from the health-care provider's perspective. One-way and probabilistic sensitivity analyses were performed. SETTING: Nairobi, Kenya. POPULATION: PWID. MEASUREMENTS: Treatment costs, incremental cost-effectiveness ratio (cost per disability-adjusted life year averted). FINDINGS: The cost per disability-adjusted life-year averted for the intervention was $975, with 92.1% of the probabilistic sensitivity analyses simulations falling below the per capita gross domestic product for Kenya ($1509; commonly used as a suitable threshold for determining whether an intervention is cost-effective). However, the intervention was not cost-effective at the opportunity cost-based cost-effectiveness threshold of $647 per disability-adjusted life-year averted. Sensitivity analyses showed that the intervention could provide more value for money by including modelled estimates for HCV disease care costs, assuming lower drug prices ($75 instead of $728 per course) and excluding directly-observed therapy costs. CONCLUSIONS: The current strategy of screening and treatment for hepatitis C virus (HCV) among people who inject drugs in Nairobi is likely to be highly cost-effective with currently available cheaper drug prices, if directly-observed therapy is not used and HCV disease care costs are accounted for.

Costs and impact on HIV transmission of a switch from a criminalisation to a public health approach to injecting drug use in eastern Europe and central Asia: a modelling analysis.

BACKGROUND: HIV incidence is increasing in eastern Europe and central Asia, primarily driven by injecting drug use. Coverage of antiretroviral therapy (ART) and opioid agonist therapy are suboptimal, with many people who inject drugs (PWID) being incarcerated. We aimed to assess whether use of monies saved as a result of decriminalisation of drug use or possession to scale up ART and opioid agonist therapy could control HIV transmission among PWID in eastern Europe and central Asia. METHODS: A dynamic HIV transmission model among PWID incorporating incarceration, ART, and opioid agonist therapy was calibrated to Belarus, Kazakhstan, Kyrgyzstan, and St Petersburg (Russia). Country-specific costs for opioid agonist therapy, ART, and incarceration were collated or estimated. Compared with baseline, the model prospectively projected the life-years gained, incremental costs (2018 euros), and infections prevented over 2020-40 for three scenarios. The decriminalisation scenario removed incarceration resulting from drug use or possession for personal use, reducing incarceration among PWID by 24·8% in Belarus, Kazakhstan, and Kyrgyzstan and 46·4% in St Petersburg; the public health approach scenario used savings from decriminalisation to scale up ART and opioid agonist therapy; and the full scale-up scenario included the decriminalisation scenario plus investment of additional resources to scale up ART to the UNAIDS 90-90-90 target of 81% coverage and opioid agonist therapy to the WHO target of 40% coverage. The incremental cost-effectiveness ratios per life-year gained for each scenario were calculated and compared with country-specific gross domestic product per-capita willingness-to-pay thresholds. Costs and life-years gained were discounted 3% annually. FINDINGS: Current levels of incarceration, opioid agonist therapy, and ART were estimated to cost from €198 million (95% credibility interval 173-224) in Kyrgyzstan to €4129 million (3897-4358) in Kazakhstan over 2020-40; 74·8-95·8% of these total costs were incarceration costs. Decriminalisation resulted in cost savings (€38-773 million due to reduced prison costs; 16·9-26·1% reduction in overall costs) but modest life-years gained (745-1694). The public health approach was cost saving, allowing each setting to reach 81% ART coverage and 29·7-41·8% coverage of opioid agonist therapy, resulting in 17 768-148 464 life-years gained and 58·9-83·7% of infections prevented. Results were similar for the full scale-up scenario. INTERPRETATION: Cost savings from decriminalisation of drug use could greatly reduce HIV transmission through increased coverage of opioid agonist therapy and ART among PWID in eastern Europe and central Asia. FUNDING: Alliance for Public Health, US National Institute of Allergy and Infectious Diseases and National Institute for Drug Abuse, and Economist Intelligence Unit.

Cost-effectiveness of mass screening for Hepatitis C virus among all inmates in an Irish prison.

BACKGROUND: In Irish prisons, there is a high proportion of people who inject drugs (PWID; 26%) and a high prevalence of HCV (16%), making prison a high priority setting for HCV testing and treatment. We evaluate the cost-effectiveness of a mass HCV screening intervention in Mountjoy Prison, Dublin, compared to the standard-of-care of intermittent screening on committal. METHODS: Primary cost data was collected from the intervention using an overall provider perspective. Standard-of-care (SOC) costs were estimated through interview. All costs were inflated to 2020 Euros. An HCV transmission and disease progression model among incarcerated and community PWID and ex-injectors was calibrated to the Dublin HCV epidemic, allowing inclusion of population-level health benefits. The model used intervention data, suggesting 419 individuals were screened, 50 HCV infections diagnosed and 32 individuals initiated treatment, to project the resulting costs and health benefits (quality adjusted life years or QALYs) over 50 years with 5% discounting. The incremental cost effectiveness ratio (ICER), cost per QALY gained, was estimated for the screening intervention compared to the standard-of-care. Probabilistic sensitivity analyses (PSA) determined the probability that the intervention was cost-effective compared to a willingness-to-pay threshold of €30,000/QALY as used in Ireland. The ICER for 1- or 3-yearly mass screening in all Dublin prisons was also calculated. RESULTS: The total direct costs of the intervention (not including treatment drug costs) was €82,392, with most costs being due to staff (43%) and overhead or management costs (38%). Despite having little epidemiological impact due to the small numbers treated, over 50 years the incremental cost of the intervention was €36,592 and 3.8 QALYs were gained, giving a mean ICER of €9,552/QALY. The majority (84%) of PSA runs were below the willingness-to-pay threshold. Yearly mass screening had an ICER of €2,729/QALY compared to SOC and gave a higher net monetary benefit (€7,393,382) than screening every 3 years (€6,252,816). CONCLUSION: Prison mass screening could be a cost-effective initiative for increasing testing and treatment of HCV in Ireland.

Has resourcing of non-governmental harm-reduction organizations in Ukraine improved HIV prevention and treatment outcomes for people who inject drugs? Findings from multiple bio-behavioural surveys.

INTRODUCTION: People who inject drugs (PWID) in Ukraine have high prevalences of HIV and hepatitis C (HCV). Since the turn of the century, various organizations have funded non-governmental organizations (NGOs) in Ukraine to provide PWID with needles and syringes, condoms, HIV and HCV testing, and improve linkage to opioid agonist therapy (OAT) and HIV treatment. We investigated whether contact with these NGOs was associated with improved HIV prevention and treatment outcomes among PWID. METHODS: Five rounds of respondent-driven sampled integrated bio-behavioural survey data (2009 [N = 3962], 2011 [N = 9069], 2013 [N = 9502], 2015 [N = 9405], and 2017 [N = 10076]) among PWID in Ukraine (including HIV/HCV testing and questionnaires) were analysed using mixed-effect logistic regression models (mixed-effects: city, year). These regression models assessed associations between being an NGO client and various behavioural, OAT, HIV testing and HIV treatment outcomes, adjusting for demographic characteristics (age, gender, lifetime imprisonment, registration in a drug abuse clinic, education level). We also assessed associations between being an NGO client and being HIV positive or HCV positive, likewise adjusting for demographic characteristics (as above). RESULTS: NGO clients were more likely to have received HIV testing ever (adjusted odds ratio [aOR] 5.37, 95% confidence interval [95% CI]: 4.97 to 5.80) or in the last year (aOR 3.37, 95% CI: 3.20 to 3.54), to have used condoms at last sexual intercourse (aOR 1.37, 95% CI: 1.30 to 1.44) and sterile needles at last injection (aOR 1.37, 95% CI: 1.20 to 1.56), to be currently (aOR 4.19, 95% CI: 3.48 to 5.05) or ever (aOR 2.52, 95% CI: 2.32 to 2.74) on OAT, and to have received syringes (aOR 109.89, 95% CI: 99.26 to 121.66) or condoms (aOR 54.39, 95% CI: 50.17 to 58.96) in the last year. PWID who were HIV positive (aOR 1.40, 95% CI: 1.33 to 1.48) or HCV positive (aOR 1.57, 95% CI: 1.49 to 1.65) were more likely to have contact with NGOs, with HIV positive PWID in contact with NGOs being more likely to be registered at AIDS centres (aOR 2.34, 95% CI: 1.88 to 2.92) and to be on antiretroviral therapy (aOR 1.60, 95% CI: 1.40 to 1.83). CONCLUSIONS: Contact with PWID targeted NGOs in Ukraine is associated with consistently better preventive, HIV testing and HIV treatment outcomes, suggesting a beneficial impact of harm reduction NGO programming.

Socio-demographic and ecological factors associated with anti-HCV prevalence in people who inject drugs: A systematic review.

BACKGROUND: The World Health Organization (WHO) aim to eliminate hepatitis C virus (HCV) as a public health threat by 2030. People who inject drugs (PWID) are a key risk group for HCV transmission globally. We explored socio-demographic and ecological variables associated with HCV antibody (anti-HCV) prevalence among samples of PWID. METHODS: We systematically searched for and screened journal articles and online reports published between January 2011 and June 2017. Serologically confirmed anti-HCV prevalence among PWID and other study-level socio-demographic variables were extracted. Country-level ecological indicators were sourced from online databases. We used generalized linear models to investigate associations between anti-HCV prevalence estimates and other study-level and country-level variables. RESULTS: There were 223 studies from 84 countries contributing 569 estimates of anti-HCV prevalence among PWID. Among study-level indicators, higher levels of anti-HCV prevalence were associated with higher HIV prevalence (B = 0.20; 95 % Confidence Interval [95 %CI] = 0.12, 0.29, p < 0.001) and year of data collection (B=-0.08; 95 %CI=-0.15, -0.02; p = 0.011). At a national level, higher Human Development Index scores (B=4.37; 95 %CI=0.12, 8.63, p = 0.044) were associated with higher levels of anti-HCV in samples. IMPLICATIONS: Serological surveillance data are increasingly available globally; however, there are still geographical gaps in quantification of HCV prevalence among PWID that must be addressed to inform efforts to achieve HCV elimination. Anti-HCV prevalence was lower in samples of PWID from countries with lower Human Development Index scores, which points to an opportunity to provide targeted intervention and potentially control transmission rates of infection in countries characterized by poor population health, education, and income.

Prevalence and burden of HBV co-infection among people living with HIV: A global systematic review and meta-analysis.

Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV.

The Potential Impact of a Hepatitis C Vaccine for People Who Inject Drugs: Is a Vaccine Needed in the Age of Direct-Acting Antivirals?

BACKGROUND AND AIMS: The advent of highly effective hepatitis C (HCV) treatments has questioned the need for a vaccine to control HCV amongst people who inject drugs (PWID). However, high treatment costs and ongoing reinfection risk suggest it could still play a role. We compared the impact of HCV vaccination amongst PWID against providing HCV treatment. METHODS: Dynamic HCV vaccination and treatment models among PWID were used to determine the vaccination and treatment rates required to reduce chronic HCV prevalence or incidence in the UK over 20 or 40 years. Projections considered a low (50% protection for 5 years), moderate (70% protection for 10 years) or high (90% protection for 20 years) efficacy vaccine. Sensitivities to various parameters were examined. RESULTS: To halve chronic HCV prevalence over 40 years, the low, moderate and high efficacy vaccines required annual vaccination rates (coverage after 20 years) of 162 (72%), 77 (56%) and 44 (38%) per 1000 PWID, respectively. These vaccination rates were 16, 7.6 and 4.4 times greater than corresponding treatment rates. To halve prevalence over 20 years nearly doubled these vaccination rates (moderate and high efficacy vaccines only) and the vaccination-to-treatment ratio increased by 20%. For all scenarios considered, required annual vaccination rates and vaccination-to-treatment ratios were at least a third lower to reduce incidence than prevalence. Baseline HCV prevalence had little effect on the vaccine's impact on prevalence or incidence, but substantially affected the vaccination-to-treatment ratios. Behavioural risk heterogeneity only had an effect if we assumed no transitions between high and low risk states and vaccinations were targeted or if PWID were high risk for their first year. CONCLUSIONS: Achievable coverage levels of a low efficacy prophylactic HCV vaccine could greatly reduce HCV transmission amongst PWID. Current high treatment costs ensure vaccination could still be an important intervention option.

The role of a hepatitis C virus vaccine: modelling the benefits alongside direct-acting antiviral treatments.

BACKGROUND: Hepatitis C virus (HCV) elimination is being seriously considered globally. Current elimination models require a combination of highly effective HCV treatment and harm reduction, but high treatment costs make such strategies prohibitively expensive. Vaccines should play a key role in elimination but their best use alongside treatments is unclear. For three vaccines with different efficacies we used a mathematical model to estimate the additional reduction in HCV prevalence when vaccinating after treatment; and to identify in which settings vaccines could most effectively reduce the number of treatments required to achieve fixed reductions in HCV prevalence among people who inject drugs (PWID). METHODS: A deterministic model of HCV transmission among PWID was calibrated for settings with 25, 50 and 75% chronic HCV prevalence among PWID, stratified by high-risk or low-risk PWID. For vaccines with 30, 60 or 90% efficacies, different rates of treatment and vaccination were introduced. We compared prevalence reductions achieved by vaccinating after treatment to prevent reinfection and vaccinating independently of treatment history in the community; and by allocating treatments and vaccinations to specific risk groups and proportionally across risk groups. RESULTS: Vaccinating after treatment was minimally different to vaccinating independently of treatment history, and allocating treatments and vaccinations to specific risk groups was minimally different to allocating them proportionally across risk groups. Vaccines with 30 or 60% efficacy provided greater additional prevalence reduction per vaccination in a setting with 75% chronic HCV prevalence among PWID than a 90% efficacious vaccine in settings with 25 or 50% chronic HCV prevalence among PWID. CONCLUSIONS: Vaccinating after treatment is an effective and practical method of administration. In settings with high chronic HCV prevalence among PWID, even modest coverage with a low-efficacy vaccine could provide significant additional prevalence reduction beyond treatment alone, and would likely reduce the cost of achieving prevalence reduction targets.

Is bariatric surgery safe in academic centers?

Contemporary outcomes of bariatric surgery are not well defined. Our aim was to document the outcomes of bariatric surgery on the basis of surgeon caseload and affiliation. We analyzed prospectively collected Florida-wide hospital discharge data. Forty-four surgeons undertook bariatric surgery in 933 patients during 1999. The ten surgeons who averaged more than two operations/month undertook 764 operations; 162 (17%) were done by academic surgeons. Complications [14% vs 7% (P = 0.008, chi-square)], length of stay (5 +/- 0.7 vs 4 +/- 0.1 days), and hospital charges (in thousands) ($31 +/- 4.0 vs $24 +/- 0.4) were greater in academic than in community-based centers (P < 0.05, Wilcoxon rank-sum). However, 36 per cent of patients operated upon by academic surgeons had a high Severity Index compared with only 16 per cent of patients operated upon by community-based surgeons (P < 0.001, chi-square). In high-risk patients complications (40% vs 46%), length of stay (7 +/- 1.0 vs 6 +/- 0.4 days), and hospital charges (in thousands) ($42 +/- 6 vs $35 +/- 2) were similar between academic and community-based surgeons. We conclude that outcomes of bariatric surgery in high-risk patients are similar among academic and community-based surgeons. Academic surgeons undertake bariatric surgery in high-risk patients more frequently than community-based surgeons, which underlies their increased complication rate. These prospectively collected data reflect surgical outcomes more accurately than clinical series and will impact our practice of bariatric surgery.