Medicine (St Vincent's) - Research Publications

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    The Global Impact of Hepatitis B Vaccination on Hepatocellular Carcinoma
    Flores, JE ; Thompson, AJ ; Ryan, M ; Howell, J (MDPI, 2022-05-01)
    Over 1.5 million preventable new hepatitis B infections continue to occur each year and there are an estimated 296 million people living with chronic hepatitis B infection worldwide, resulting in more than 820,000 deaths annually due to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B vaccination remains the cornerstone of public health policy to prevent HCC and a vital component of the global hepatitis B elimination response. The WHO has set a 90% vaccination target to achieve hepatitis B elimination by 2030; however, there is wide variability in reported birth dose coverage, with global coverage at only 42%. In this review, we outline the global trends in hepatitis B vaccination coverage and the impact of hepatitis B vaccination on HCC incidence and discuss the challenges and enabling factors for achieving WHO 2030 hepatitis B vaccination coverage targets.
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    Liver Disease and Poor Adherence Limit Hepatitis C Cure: A Real-World Australian Treatment Cohort.
    Clark, PJ ; Valery, PC ; Strasser, SI ; Weltman, M ; Thompson, AJ ; Levy, M ; Leggett, B ; Zekry, A ; Rong, J ; Angus, P ; George, J ; Bollipo, S ; McGarity, B ; Sievert, W ; Macquillan, G ; Tse, E ; Nicoll, A ; Wade, A ; Chu, G ; Harding, D ; Cheng, W ; Farrell, G ; Roberts, SK (Springer Science and Business Media LLC, 2022-05-13)
    BACKGROUND AND AIMS: In 2016, direct-acting antiviral (DAA) treatment for hepatitis C (HCV) became available through Australia's universal health care system, with the aim of HCV elimination. We report real-world effectiveness of DAA HCV treatment in Australia from a clinically well-informed cohort, enriched for cirrhosis and prior HCV treatment. METHODS: 3413 patients were recruited from 26 hospital liver clinics across Australia from February 2016 to June 2020. Clinical history and sustained viral response (SVR) were obtained from medical records and data linkage to the Australian Pharmaceutical Benefits Scheme. Factors associated with SVR were assessed by multivariable logistic regression (MVR). RESULTS: At recruitment, 32.2% had cirrhosis (72.9% Child Pugh class B/C), and 19.9% were treatment experienced. Of the 2,939 with data, 93.3% confirmed SVR. 137 patients received second-line therapy. Patients with cirrhosis had lower SVR rate (88.4 vs. 95.8%; p < 0.001). On MVR, failure to achieve SVR was associated with Genotype 3 (adj-OR = 0.42, 95%CI 0.29-0.61), male gender (adj-OR = 0.49, 95%CI 0.31-0.77), fair/poor adherence (adj-OR = 0.52, 95%CI 0.28-0.94), cirrhosis (adj-OR = 0.57, 95%CI 0.36-0.88), FIB-4 > 3.25 (adj-OR = 0.52, 95%CI 0.33-0.83) and MELD score ≥ 20 (adj-OR = 0.25, 95%CI 0.08-0.80). Consistent results were seen in cirrhotic sub-analysis. CONCLUSIONS: Excellent SVR rates were achieved with DAAs in this real-world cohort of patients with chronic HCV infection. More advanced liver disease and clinician impression of poor adherence were associated with HCV treatment failure. Supports to improve liver fibrosis assessment skills for non-specialist DAA prescribers in the community and to optimize patient adherence are likely to enable more effective pursuit of HCV elimination in Australia.
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    Platinum dissolution and tissue response following long-term electrical stimulation at high charge densities
    Shepherd, RK ; Carter, PM ; Dalrymple, AN ; Enke, YL ; Wise, AK ; Nguyen, T ; Firth, J ; Thompson, A ; Fallon, JB (IOP PUBLISHING LTD, 2021-04-01)
    Objective. Established guidelines for safe levels of electrical stimulation for neural prostheses are based on a limited range of the stimulus parameters used clinically. Recent studies have reported particulate platinum (Pt) associated with long-term clinical use of these devices, highlighting the need for more carefully defined safety limits. We previously reported no adverse effects of Pt corrosion products in the cochleae of guinea pigs following 4 weeks of electrical stimulation using charge densities far greater than the published safe limits for cochlear implants. The present study examines the histopathological effects of Pt within the cochlea following continuous stimulation at a charge density well above the defined safe limits for periods up to 6 months.Approach. Six cats were bilaterally implanted with Pt electrode arrays and unilaterally stimulated using charge balanced current pulses at a charge density of 267μC cm-2phase-1using a tripolar electrode configuration. Electrochemical measurements were made throughout the implant duration and evoked potentials recorded at the outset and on completion of the stimulation program. Cochleae were examined histologically for particulate Pt, tissue response, and auditory nerve survival; electrodes were examined for surface corrosion; and cochlea, brain, kidney, and liver tissue analysed for trace levels of Pt.Main results. Chronic stimulation resulted in both a significant increase in tissue response and particulate Pt within the tissue capsule surrounding the electrode array compared with implanted, unstimulated control cochleae. Importantly, there was no stimulus-induced loss of auditory neurons (ANs) or increase in evoked potential thresholds. Stimulated electrodes were significantly more corroded compared with unstimulated electrodes. Trace analysis revealed Pt in both stimulated and control cochleae although significantly greater levels were detected within stimulated cochleae. There was no evidence of Pt in brain or liver; however, trace levels of Pt were recorded in the kidneys of two animals. Finally, increased charge storage capacity and charge injection limit reflected the more extensive electrode corrosion associated with stimulated electrodes.Significance. Long-term electrical stimulation of Pt electrodes at a charge density well above existing safety limits and nearly an order of magnitude higher than levels used clinically, does not adversely affect the AN population or reduce neural function, despite a stimulus-induced tissue response and the accumulation of Pt corrosion product. The mechanism resulting in Pt within the unstimulated cochlea is unclear, while the level of Pt observed systemically following stimulation at these very high charge densities does not appear to be of clinical significance.
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    Hepatitis B and pregnancy: understanding the experiences of care among pregnant women and recent mothers in metropolitan Melbourne
    Ahad, M ; Wallace, J ; Xiao, Y ; van Gemert, C ; Bennett, G ; Darby, J ; Desmond, P ; Hall, S ; Holmes, J ; Papaluca, T ; Glasgow, S ; Thompson, A ; Hellard, M ; Doyle, J ; Howell, J (BMC, 2022-04-23)
    BACKGROUND: Pregnant women are a priority group for hepatitis B testing. Guideline-based care during antenatal and post-partum periods aims to prevent mother-to-child transmission of hepatitis B virus and lower the risk of liver complications in mothers. This qualitative study explored knowledge of hepatitis B and experiences of hepatitis B related care among pregnant women and mothers. METHODS: Semi-structured interviews were conducted with thirteen women with hepatitis B who were attending antenatal or post-partum hepatitis B care. The interviews were thematically analysed to assess knowledge and understanding of hepatitis B. Participants were recruited from specialist clinics in metropolitan Melbourne between August 2019 and May 2020. RESULTS: Four major themes were identified from interviews: (1) knowledge and understanding of hepatitis B, (2) treatment pathways, (3) accessing hepatitis B related care, and (4) disclosing status to friends. Most participants displayed an understanding of hepatitis B transmission, including mother to child transmission. The main motivator of post-partum attendance was reassurance gained concerning their child's health. Sources of hepatitis B information included doctors, online information and family. Participants identified parents and siblings as sources of support and reported an unwillingness to disclose hepatitis B status to friends. CONCLUSIONS: Women attending antenatal or post-partum care reported having overall positive experiences, particularly regarding reassurance of their child's health, but displayed misconceptions around horizontal transmission. Knowledge gained from these results can contribute to the development of targeted models of care for pregnant women and mothers with young children to ensure their successful linkage to care.
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    Randomised controlled trial of active case management to link hepatitis C notifications to treatment in Tasmania, Australia: a study protocol.
    Marukutira, T ; Moore, KP ; Hellard, M ; Richmond, J ; Turner, K ; Pedrana, AE ; Melody, S ; Johnston, FH ; Owen, L ; Van Den Boom, W ; Scott, N ; Thompson, A ; Iser, D ; Spelman, T ; Veitch, M ; Stoové, MA ; Doyle, J (BMJ, 2022-03-25)
    INTRODUCTION: By subsidising access to direct acting antivirals (DAAs) for all people living with hepatitis C (HCV) in 2016, Australia is positioned to eliminate HCV as a public health threat. However, uptake of DAAs has declined over recent years and new initiatives are needed to engage people living with HCV in care. Active follow-up of HCV notifications by the health department to the notifying general practitioner (GP) may increase treatment uptake. In this study, we explore the impact of using hepatitis C notifications systems to engage diagnosing GPs and improve patient access to treatment. METHODS AND ANALYSIS: This study is a randomised controlled trial comparing enhanced case management of HCV notifications with standard of care. The intervention includes phone calls from a department of health (DoH) specialist HCV nurse to notifying GPs and offering HCV management support. The level of support requested by the GP was graded in complexity: level 1: HCV information only; level 2: follow-up testing advice; level 3: prescription support including linkage to specialist clinicians and level 4: direct patient contact. The study population includes all GPs in Tasmania who notified HCV diagnosis to the DoH between September 2020 and December 2021. The primary outcome is proportion of HCV cases who initiate DAAs after 12 weeks of HCV notification to the health department. Secondary outcomes are proportion of HCV notifications that complete HCV RNA testing, treatment workup and treatment completion. Multiple logistic regression modelling will explore factors associated with the primary and secondary outcomes. The sample size required to detect a significant difference for the primary outcome is 85 GPs in each arm with a two-sided alpha of 0.05% and 80% power. ETHICS AND DISSEMINATION: The study was approved by University of Tasmania's Human Research Ethics Committee (Protocol ID: 18418) on 17 December 2019. Results of the project will be presented in scientific meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04510246. TRIAL PROGRESSION: The study commenced recruitment in September 2020 and end of study expected December 2021.
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    The Importance of Prisons in Achieving Hepatitis C Elimination: Insights from the Australian Experience.
    Winter, RJ ; Holmes, JA ; Papaluca, TJ ; Thompson, AJ (MDPI AG, 2022-02-28)
    Following the availability of highly effective direct-acting antivirals (DAAs) to treat hepatitis C infection, the uptake of treatment by people living with hepatitis C rose dramatically in high- and middle-income countries but has since declined. To achieve the World Health Organization's (WHO) 2030 target to eliminate hepatitis C as a public health threat among people who inject drugs, an increase in testing and treatment is required, together with improved coverage of harm reduction interventions. The population that remains to be treated in high- and middle-income countries with high hepatitis C prevalence are among the most socially disadvantaged, including people who inject drugs and are involved in the criminal justice system, a group with disproportionate hepatitis C prevalence, compared with people in the wider community. Imprisonment provides an unrivalled opportunity for screening and treating large numbers of people for hepatitis C, who may not access mainstream health services in the community. Despite some implementation challenges, evidence of the efficacy, acceptability, and cost-effectiveness of in-prison hepatitis treatment programs is increasing worldwide, and evaluations of these programs have demonstrated the capacity for treating people in high numbers. In this Perspective we argue that the scale-up of hepatitis C prevention, testing, and treatment programs in prisons, along with the investigation of new and adapted approaches, is critical to achieving WHO elimination goals in many regions; the Australian experience is highlighted as a case example. We conclude by discussing opportunities to improve access to prevention, testing, and treatment for people in prison and other justice-involved populations, including harnessing the changed practices brought about by the COVID-19 pandemic.
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    Reducing liver disease-related deaths in the Asia-Pacific: the important role of decentralised and non-specialist led hepatitis C treatment for cirrhotic patients.
    Draper, B ; Yee, WL ; Pedrana, A ; Kyi, KP ; Qureshi, H ; Htay, H ; Naing, W ; Thompson, AJ ; Hellard, M ; Howell, J (Elsevier BV, 2022-03)
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    Real-world monitoring progress towards the elimination of hepatitis C virus in Australia using sentinel surveillance of primary care clinics; an ecological study of hepatitis C virus antibody tests from 2009 to 2019
    Wilkinson, AL ; Pedrana, A ; Traeger, MW ; Asselin, J ; El-Hayek, C ; Nguyen, L ; Polkinghorne, V ; Doyle, JS ; Thompson, AJ ; Howell, J ; Scott, N ; Dimech, W ; Guy, R ; Hellard, M (CAMBRIDGE UNIV PRESS, 2021-12-06)
    To achieve the elimination of the hepatitis C virus (HCV), sustained and sufficient levels of HCV testing is critical. The purpose of this study was to assess trends in testing and evaluate the effectiveness of strategies to diagnose people living with HCV. Data were from 12 primary care clinics in Victoria, Australia, that provide targeted services to people who inject drugs (PWID), alongside general health care. This ecological study spanned 2009-2019 and included analyses of trends in annual numbers of HCV antibody tests among individuals with no previous positive HCV antibody test recorded and annual test yield (positive HCV antibody tests/all HCV antibody tests). Generalised linear models estimated the association between count outcomes (HCV antibody tests and positive HCV antibody tests) and time, and χ2 test assessed the trend in test yield. A total of 44 889 HCV antibody tests were conducted 2009-2019; test numbers increased 6% annually on average [95% confidence interval (CI) 4-9]. Test yield declined from 2009 (21%) to 2019 (9%) (χ2P = <0.01). In more recent years (2013-2019) annual test yield remained relatively stable. Modest increases in HCV antibody testing and stable but high test yield within clinics delivering services to PWID highlights testing strategies are resulting in people are being diagnosed however further increases in the testing of people at risk of HCV or living with HCV may be needed to reach Australia's HCV elimination goals.
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    Assessment of the cost-effectiveness of Australia's risk-sharing agreement for direct-acting antiviral treatments for hepatitis C: a modelling study
    Scott, N ; Palmer, A ; Tidhar, T ; Stoove, M ; Sacks-Davis, R ; Doyle, JS ; Pedrana, A ; Thompson, AJ ; Wilson, DP ; Hellard, M (ELSEVIER, 2021-12-11)
    BACKGROUND: Hepatitis C elimination may be possible with broad uptake of direct-acting antiviral treatments (DAAs). In 2016 the Australian government committed A$1.2 billion for five years of unlimited DAAs (March 2016 to February 2021) in a risk-sharing agreement with pharmaceutical companies. We assess the impact, cost-effectiveness and net economic benefits likely to be realised from this investment. METHODS: Mathematical modelling to project outcomes for 2016-2030 included: (S1) a counter-factual scenario (testing/treatment maintained at pre-2016 levels); (S2) the current status-quo (testing/treatment as actually occurred 2016-2019, with trends maintained to 2030); and (S3) elimination scenario (S2 plus testing/treatment rates increased between 2021-2030 to achieve the WHO elimination targets). FINDINGS: S1 resulted in 68,800 new hepatitis C infections and 18,540 hepatitis C-related deaths over 2016-2030. The total health system cost (HCV testing, treatment, disease management) was A$3.01 billion and the cost of lost productivity due to absenteeism, presenteeism and premature deaths was A$26.14 billion. S2 averted 15,700 (23%) new infections and 8,500 (46%) deaths by 2030, with a total health system cost of A$3.48 billion, A$472 million more than S1 (A$1.65 billion more in testing/treatment but A$1.20 billion less in disease costs; A$5,752 per QALY gained from a health systems perspective). Productivity loss over 2016-2030 was A$19.96 billion, A$6.17 less than S1, making S2 cost-saving from a societal perspective by 2022 with a net economic benefit of A$5.70 billion by 2030. S3 averted an additional 10,000 infections and 930 deaths compared with S2 and increased the longer-term economic benefit. INTERPRETATION: Five years of unrestricted access to DAAs in Australia has led to significant health benefits and is likely to become cost-saving from a societal perspective by 2022. FUNDING: Burnet Institute.
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    A problem of proportions: estimates of metabolic associated fatty liver disease and liver fibrosis in Australian adults in the nationwide 2012 AusDiab Study
    Farrell, AM ; Magliano, DJ ; Shaw, JE ; Thompson, AJ ; Croagh, C ; Ryan, MC ; Howell, J (NATURE PORTFOLIO, 2022-02-04)
    Metabolic Associated Fatty Liver Disease (MAFLD) is the most common cause of liver disease in Australia, but prevalence data are limited. We aimed to describe the frequency of alanine aminotransferase (ALT) elevation, and MAFLD within a large prospective Australian cohort. Cross-sectional analysis of the 2012 survey of the Australian Diabetes, Obesity and Lifestyle (AusDiab) study which included 4747 Australian adults (aged 34-97 yrs) was performed. Frequency of ALT elevation (men ≥ 40 IU/L, women ≥ 30 IU/L) and MAFLD (Fatty Liver Index (FLI) > 60 alongside metabolic risk factors) was determined and risk of advanced fibrosis stratified using the BARD score. Elevated ALT was found in 13% of the cohort, including 22% of people with diabetes, 18% with obesity, and 17% with the metabolic syndrome. 37% of the cohort had MAFLD, and those with MAFLD were more likely to be older (OR 1.01 per 1 year (95% CI 1.00-1.02)), male (OR 1.37 (95% CI 1.17-1.59)), have ALT elevation (OR 3.21 (95% CI 2.59-3.99)), diabetes (OR 3.39 (95% CI 2.61-4.39)), lower HDL-C (OR 0.15 per 1 mmol/L (95% CI 0.12-0.19)), higher diastolic blood pressure (OR 1.05 per 10 mmHg (95% CI 1.05-1.06)), a sedentary lifestyle (OR 1.99 (95% CI 1.59-2.50)) and less likely to have tertiary education (OR 0.81 (95% CI 0.7-0.94) compared to those without MAFLD. Of those with MAFLD, 61% had a BARD score suggesting risk of advanced fibrosis and 22% had an elevated ALT. Over 10% of this Australian cohort had elevated ALT, and 37% had MAFLD, with many at risk for advanced fibrosis.