ORCID Profile
0000-0002-8427-5612
Current Organisations
University of Birmingham
,
Australian Red Cross Lifeblood
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Publisher: Wiley
Date: 20-05-2019
DOI: 10.1111/VOX.12790
Publisher: Wiley
Date: 23-09-2021
DOI: 10.1111/VOX.13011
Publisher: Wiley
Date: 24-05-2022
DOI: 10.1111/VOX.13290
Abstract: Most of the 233 worldwide cases of variant Creutzfeldt–Jakob disease (vCJD) have been reported in the United Kingdom and 3 have been associated with transfusion‐transmission. To mitigate the potential vCJD risk to blood safety, Australian Red Cross Lifeblood imposes restrictions on blood donation from people with prior residency in, or extended travel to, the United Kingdom during the risk period 1980–1996. We have modified a previously published methodology to estimate the transfusion‐transmission risk of vCJD associated with fresh component transfusion in Australia if the UK residence deferral was removed. The prevalence of current pre‐symptomatic vCJD infection in the United Kingdom by age at infection and genotype was estimated based on risk of exposure to the bovine spongiform encephalopathy agent for the period 1980–1996. These results were used to estimate the age‐specific prevalence of undiagnosed, pre‐symptomatic vCJD in the Australian population in the current year due to prior UK residency or travel. The primary model outputs were the 2020 vCJD risks/unit of vCJD contamination, transfusion‐transmission (infections) and clinical cases. The overall (prior UK residency in and travel to United Kingdom, 1980–1996) mean risk of contamination per unit was 1 in 29,900,000. The risks of resulting vCJD transmission (infection) and clinical case were 1 in 389,000,000 and 1 in 1,450,000,000, respectively. Our modelling suggests that removing the Lifeblood donation deferral for travel to, or UK residence, would result in virtually no increased risk of vCJD transfusion‐transmission and would be a safe and effective strategy for increasing the donor base.
Publisher: Centers for Disease Control and Prevention (CDC)
Date: 10-2019
Publisher: Wiley
Date: 23-10-2019
DOI: 10.1111/TRF.15548
Abstract: Foodborne hepatitis A virus (HAV) outbreaks are becoming more common in high-income countries with low HAV incidence, and the associated blood safety risk may not be adequately mitigated by routine HAV risk mitigation strategies. This study describes the rapid risk modeling undertaken in response to a 2018 HAV outbreak in Australia associated with imported frozen pomegranate arils. The input parameters used in the modeling were the outbreak-associated HAV incidence, duration of viremia, population seroprevalence, and rate of symptomatic infection in adults. The number and risk of viremic components issued, cases of transfusion transmission, and symptomatic infections among recipients were estimated. The incidence of pomegranate-associated HAV infection among donors was very low, with fewer than 0.1 viremic fresh components estimated to have been released during the risk period. The risk of this event was less than one in 500,000, and the risks of transfusion transmission and symptomatic illness in recipients were less than one in one million. When considering only donors who had consumed the pomegranate product, the risk was much higher, with approximately one in 1000 components estimated to be viremic. Rapid risk assessment indicated that the overall risk to blood safety associated with a small foodborne outbreak of HAV was negligible. Because fresh components collected from donors known to have consumed the affected product were at high risk, these donors were identified via signage in donor centers and deferred. The contribution of factors other than outbreak size to risk management decisions is discussed.
Publisher: Wiley
Date: 27-12-2019
DOI: 10.1111/TRF.14965
Abstract: Three probable cases of transfusion-transmitted (TT) parvovirus B19 (B19V) occurred in Australia between 2014 and 2017. This study aimed to determine the B19V DNA prevalence among blood donors, to model the risk to recipients of fresh components, and to assess risk management options. Plasma s les from 4232 donors were tested for B19V DNA by polymerase chain reaction. Reactive s les were confirmed and viral load determined. A transmission-risk model was used to estimate recipient risk, and the risk from community exposure was estimated using seroprevalence data. Two s les (0.0473%, 95% confidence interval [CI] 0.0130-0.172) confirmed positive for B19V DNA had a potentially infectious viral load of 10 In the context of the small contribution of transfusion to the burden of B19V disease, the significant costs that would be incurred by any strategy to reduce the risk, and given the significant uncertainties and likely overestimation of the risk, we conclude TT-B19V is a tolerable risk to blood safety, despite being high for some vulnerable recipient groups.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Wiley
Date: 25-02-2023
DOI: 10.5694/MJA2.51863
Publisher: S. Karger AG
Date: 29-08-2020
DOI: 10.1159/000502552
Publisher: Wiley
Date: 06-06-2023
DOI: 10.5694/MJA2.52001
Publisher: Wiley
Date: 18-04-2016
Publisher: Wiley
Date: 23-11-2020
DOI: 10.1111/TRF.15598
Publisher: Public Library of Science (PLoS)
Date: 12-08-2021
DOI: 10.1371/JOURNAL.PONE.0254698
Abstract: Pneumonia is a common and severe complication of abdominal surgery, it is associated with increased length of hospital stay, healthcare costs, and mortality. Further, pulmonary complication rates have risen during the SARS-CoV-2 pandemic. This study explored the potential cost-effectiveness of administering preoperative chlorhexidine mouthwash versus no-mouthwash at reducing postoperative pneumonia among abdominal surgery patients. A decision analytic model taking the South African healthcare provider perspective was constructed to compare costs and benefits of mouthwash versus no-mouthwash-surgery at 30 days after abdominal surgery. We assumed two scenarios: (i) the absence of COVID-19 (ii) the presence of COVID-19. Input parameters were collected from published literature including prospective cohort studies and expert opinion. Effectiveness was measured as proportion of pneumonia patients. Deterministic and probabilistic sensitivity analyses were performed to assess the impact of parameter uncertainties. The results of the probabilistic sensitivity analysis were presented using cost-effectiveness planes and cost-effectiveness acceptability curves. In the absence of COVID-19, mouthwash had lower average costs compared to no-mouthwash-surgery, $3,675 (R 63,770) versus $3,958 (R 68,683), and lower proportion of pneumonia patients, 0.029 versus 0.042 (dominance of mouthwash intervention). In the presence of COVID-19, the increase in pneumonia rate due to COVID-19, made mouthwash more dominant as it was more beneficial to reduce pneumonia patients through administering mouthwash. The cost-effectiveness acceptability curves shown that mouthwash surgery is likely to be cost-effective between $0 (R0) and $15,000 (R 260,220) willingness to pay thresholds. Both the absence and presence of SARS-CoV-2, mouthwash is likely to be cost saving intervention for reducing pneumonia after abdominal surgery. However, the available evidence for the effectiveness of mouthwash was extrapolated from cardiac surgery there is now an urgent need for a robust clinical trial on the intervention on non-cardiac surgery.
Publisher: Wiley
Date: 04-05-2014
DOI: 10.1111/TRF.12649
Abstract: To be eligible to donate blood, potential donors must meet certain eligibility criteria to ensure safety to the donor and to the blood supply. In Australia, there is no reliable estimate of the size of the donor-eligible population. This study uses a refinement to a published method to determine the population prevalence of donor-exclusion factors and subsequently estimates the size of the potential donor pool in Australia. A total of 70 donor-exclusion factors (in addition to age) were identified. The donor-eligible population was estimated by subtracting the prevalence of the exclusion factors from the total population. Prevalence of the donor-exclusion factors was adjusted for age, deferral period, and overlap of multiple conditions. Overlap was adjusted by extending a published random-probability model according to known association of epidemiologic data on overlapping conditions. The most prevalent (deferral period-adjusted) donor-exclusion factor among the 16- to 80-year-old Australian population was variant Creutzfeldt-Jakob disease-related travel risk (6.8%) followed by upper respiratory tract infections (6.4%). After exclusion of all factors, and accounting for overlapping factors, 62% of 16- to 80-year-olds or 47.3% of the total population were donor eligible in Australia. We developed a refined method for estimating the size of the donor-eligible population. Applying this method to Australia, we estimate that approximately 10.7 million people (62% of the 16- to 80-year-olds) were eligible to donate blood in Australia in 2012.
Publisher: Wiley
Date: 08-2017
DOI: 10.1111/VOX.12547
Abstract: The significance of anti-HCV immunoblot (IB) indeterminate results can be difficult to determine. We analysed results for blood donors tested on the MP Diagnostics HCV Blot 3.0 IB assay to determine whether indeterminate results representing past exposure to HCV could be distinguished from those due to non-specific reactivity. Results for all donors tested by IB during the study period (July 2010 to December 2013) were included in this study. Of 131 donors tested by IB, 34 (26.0%) were negative, 38 (29.0%) were indeterminate, and 59 (45.0%) were positive. There was no significant difference in IB band reactivity strength between indeterminate and positive donors. The PRISM HCV chemiluminescent immunoassay (ChLIA) s le to cut-off (s/co) ratio distribution for the indeterminate donors was significantly higher than for those with biological false reactivity (P = 0·037), but significantly lower than for donors who were IB positive/HCV RNA negative (P < 0·001) or IB not tested/HCV RNA positive (P < 0·001). Of donors available for follow-up, 53.1% of the indeterminate group disclosed a putative risk factor for HCV infection compared to 39.4% (P < 0·001) for the IB-negative group, 76.6% (P = 0·065) for the IB-positive group and 83.4% (P 2·00 with IB indeterminate results predict exposure to HCV, particularly in the presence of putative risk factors for HCV infection. These findings may be applied to optimizing counselling of donors with indeterminate HCV results.
Publisher: Oxford University Press (OUP)
Date: 26-07-2022
DOI: 10.1093/BJS/ZNAC195
Abstract: There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1) and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and $73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and $75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially.
Publisher: Wiley
Date: 18-12-2019
DOI: 10.1111/VOX.12741
Abstract: Donor syphilis testing began in the 1940s amidst widespread transfusion-transmitted syphilis (TTS). Since then, the introduction of penicillin, pre-donation screening questionnaires and improved storage conditions have contributed to reducing transmission risk. Consequently, universal testing may no longer be cost-effective. This study analysed alternative options for donor syphilis testing to determine the optimal strategy. A model was developed using conservative parameter estimates for factors affecting TTS and 2009-2015 Australian donations to calculate risk outcomes (TTS infections, tertiary syphilis in recipients and transfusion-associated congenital syphilis) and cost-effectiveness of alternative testing strategies. The strategies modelled were as follows: universal testing, targeted-testing of high-risk groups (males ≤50 years old and first-time donors) and no testing. The estimated risk of TTS is one in 49·5 million transfusions for universal testing, one in 6 million for targeted-testing of males ≤50 years old, one in 4 million for targeted-testing of first-time donors and one in 2·8 million for no testing. For all strategies, the risk of tertiary and congenital syphilis is <1 in 100 million. Universal testing is the least cost-effective strategy with an incremental cost-effectiveness ratio (ICER) estimated at $538·5 million per disability-adjusted life year averted. Universal testing is not required to maintain the risk of TTS within tolerable limits and is estimated to greatly exceed acceptable ICERs for blood safety interventions. However, despite a strong economic and risk-based rationale, given the epidemiology of syphilis in Australia is changing, feedback from critical stakeholders is not currently supportive of reducing testing.
Publisher: Wiley
Date: 14-10-2018
DOI: 10.1111/VOX.12721
Abstract: Repeat donors in Australia will shortly cease to be tested for human T-lymphotropic virus (HTLV), removing the ability to measure repeat donor incidence. A risk threshold for repeat donors was investigated based on previous modelling and a conservative ratio between prevalent and incident infections. It was estimated that 26 infections per 100 000 new-donor donations would be associated with an incidence in repeat donors approaching the tolerable risk threshold if sustained over several years. We propose to trigger formal risk assessment at this point, and believe this solution may be useful for other blood services that reduce their HTLV testing requirements.
Publisher: Wiley
Date: 27-09-2017
DOI: 10.1111/VOX.12597
Abstract: Universal testing of blood donations for human T-cell lymphotropic virus (HTLV) in Australia may no longer be appropriate given the low prevalence of HTLV infection and the mitigating effect of universal leucodepletion for cellular components. This study aimed to determine the most appropriate HTLV testing strategy using the Risk-Based Decision-Making Framework for Blood Safety. The risk of HTLV transfusion-transmission using three testing strategies (universal, new-donor and no testing) and cost-effectiveness of the first two strategies were assessed using adaptations of published mathematical models. The overall prevalence for 2004-2014 was three HTLV-positives per million donations. It was estimated that annually, universal testing incurred a cost of approximately AUD $3 million and prevented 83 HTLV-positive cellular components from being issued, and new-donor testing cost approximately $225 000 and prevented 81 components. The number of cases of transfusion-transmitted HTLV and HTLV-associated disease prevented per year by universal and new-donor testing was essentially equivalent. According to preset risk thresholds, the risk of transfusion-transmission was negligible for universal and new-donor testing, and minimal without testing. Transfusion-transmission of HTLV is a minimal risk in Australia even without testing. However, any revision of testing strategy must consider not only risk and cost-effectiveness, but also stakeholder, ethical and regulatory perspectives. Considering all relevant criteria, new-donor testing is judged the optimal strategy because it is able to achieve almost the same outcomes as universal testing, at a fraction of the cost.
Publisher: Wiley
Date: 11-08-2023
DOI: 10.1111/VOX.13510
Abstract: Until 25 July 2022, people who spent more than 6 months in the United Kingdom during the variant Creutzfeldt–Jakob disease (vCJD) risk period 1980–1996 (UK donors) were deferred from blood donation in Australia. Regulatory approval to remove the deferral was underpinned by published mathematical modelling predicting negligible vCJD transmission risk increase with a gain of 58,000 donations. The donor questionnaire retained the UK deferral screening question until a version update effective 12 February 2023, which enabled identification of the newly eligible cohort of UK donors. Their donations were tracked for a 6‐month period (25 July 2022–24 January 2023) and compared with baseline Lifeblood donation metrics and predicted gains. A total of 38,462 UK donors attended to donate 78,762 times in the 6 months. Of these, 32,358 donors (females = 19,456, males = 12,902) successfully donated 67,914 times representing 8.4% of total collections. Cessation of the UK deferral resulted in donation gains exceeding modelled predictions because of a higher than predicted number of donors who donated at a higher rate. Had these newly eligible donors not donated, overall donation numbers would have been 88% of target rather than the 96% achieved.
Location: United Kingdom of Great Britain and Northern Ireland
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2018
End Date: End date not available
Funder: National Health and Medical Research Council
View Funded Activity