Melbourne School of Population and Global Health - Research Publications

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    Key lessons from the COVID-19 public health response in Australia
    Basseal, JM ; Bennett, CM ; Collignon, P ; Currie, BJ ; Durrheim, DN ; Leask, J ; McBryde, ES ; McIntyre, P ; Russell, FM ; Smith, DW ; Sorrell, TC ; Marais, BJ (ELSEVIER, 2023-01)
    Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts. Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decision-making that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a 'standing threat', 10) regional and global solidarity is important. It should be acknowledged that we were unable to capture all relevant nuances and context specific differences. However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region.
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    COVID-19 infection and the broader impacts of the pandemic on healthcare workers
    Smallwood, N ; Harrex, W ; Rees, M ; Willis, K ; Bennett, CM (WILEY, 2022-06)
    The severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease or COVID-19 pandemic is associated with more than 230 million cases and has challenged healthcare systems globally. Many healthcare workers (HCWs) have acquired the infection, often through their workplace, with a significant number dying. The epidemiology of COVID-19 infection in HCWs continues to be explored, with manifold exposure risks identified, leading to COVID-19 being recognised as an occupational disease for HCWs. The physical illness due to COVID-19 in HCWs is similar to the general population, with some HCWs experiencing a long-term illness, which may impact their ability to return to work. HCWs have also been affected by the immense workplace and psychosocial disruption caused by the pandemic. The impacts on the psychological well-being of HCWs globally have been profound, with high prevalence estimates for mental health symptoms, including emotional exhaustion. Globally, governments, healthcare organisations and employers have key responsibilities, including: to be better prepared for crises with comprehensive disaster response management plans, and to protect and preserve the health workforce from the physical and psychological impacts of the pandemic. While prioritising HCWs in vaccine rollouts globally has been critical, managing exposures and outbreaks occurring in healthcare settings remains challenging and continues to lead to substantial disruption to the health workforce. Safeguarding healthcare workforces during crises is critical as we move forward on the new path of 'COVID normal'.
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    Excess all-cause mortality and COVID-19-related mortality: a temporal analysis in 22 countries, from January until August 2020.
    Achilleos, S ; Quattrocchi, A ; Gabel, J ; Heraclides, A ; Kolokotroni, O ; Constantinou, C ; Pagola Ugarte, M ; Nicolaou, N ; Rodriguez-Llanes, JM ; Bennett, CM ; Bogatyreva, E ; Schernhammer, E ; Zimmermann, C ; Costa, AJL ; Lobato, JCP ; Fernandes, NM ; Semedo-Aguiar, AP ; Jaramillo Ramirez, GI ; Martin Garzon, OD ; Mortensen, LH ; Critchley, JA ; Goldsmith, LP ; Denissov, G ; Rüütel, K ; Le Meur, N ; Kandelaki, L ; Tsiklauri, S ; O'Donnell, J ; Oza, A ; Kaufman, Z ; Zucker, I ; Ambrosio, G ; Stracci, F ; Hagen, TP ; Erzen, I ; Klepac, P ; Arcos González, P ; Fernández Camporro, Á ; Burström, B ; Pidmurniak, N ; Verstiuk, O ; Huang, Q ; Mehta, NK ; Polemitis, A ; Charalambous, A ; Demetriou, CA (Oxford University Press (OUP), 2022-02-18)
    BACKGROUND: This study aimed to investigate overall and sex-specific excess all-cause mortality since the inception of the COVID-19 pandemic until August 2020 among 22 countries. METHODS: Countries reported weekly or monthly all-cause mortality from January 2015 until the end of June or August 2020. Weekly or monthly COVID-19 deaths were reported for 2020. Excess mortality for 2020 was calculated by comparing weekly or monthly 2020 mortality (observed deaths) against a baseline mortality obtained from 2015-2019 data for the same week or month using two methods: (i) difference in observed mortality rates between 2020 and the 2015-2019 average and (ii) difference between observed and expected 2020 deaths. RESULTS: Brazil, France, Italy, Spain, Sweden, the UK (England, Wales, Northern Ireland and Scotland) and the USA demonstrated excess all-cause mortality, whereas Australia, Denmark and Georgia experienced a decrease in all-cause mortality. Israel, Ukraine and Ireland demonstrated sex-specific changes in all-cause mortality. CONCLUSIONS: All-cause mortality up to August 2020 was higher than in previous years in some, but not all, participating countries. Geographical location and seasonality of each country, as well as the prompt application of high-stringency control measures, may explain the observed variability in mortality changes.
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    Molecular Epidemiology of Penicillin-Susceptible Staphylococcus aureus Bacteremia in Australia and Reliability of Diagnostic Phenotypic Susceptibility Methods to Detect Penicillin Susceptibility.
    Coombs, GW ; Yee, NWT ; Daley, D ; Bennett, CM ; Robinson, JO ; Stegger, M ; Shoby, P ; Mowlaboccus, S (MDPI AG, 2022-08-15)
    BACKGROUND: Defined by the emergence of antibiotic resistant strains, Staphylococcus aureus is a priority bacterial species with high antibiotic resistance. However, a rise in the prevalence of penicillin-susceptible S. aureus (PSSA) bloodstream infections has recently been observed worldwide, including in Australia, where the proportion of methicillin-susceptible S. aureus causing bacteremia identified phenotypically as penicillin-susceptible has increased by over 35%, from 17.5% in 2013 to 23.7% in 2020. OBJECTIVES: To determine the population structure of PSSA causing community- and hospital-onset bacteremia in Australia and to evaluate routine phenotypic antimicrobial susceptibility methods to reliably confirm penicillin resistance on blaZ-positive S. aureus initially classified as penicillin-susceptible by the Vitek® 2 automated microbiology system. RESULTS: Whole genome sequencing on 470 PSSA collected in the 2020 Australian Group on Antimicrobial Resistance Australian Staphylococcus aureus Sepsis Outcome Programme identified 84 multilocus sequence types (STs), of which 79 (463 isolates) were grouped into 22 clonal complexes (CCs). The dominant CCs included CC5 (31.9%), CC97 (10.2%), CC45 (10.0%), CC15 (8.7%), and CC188 (4.9%). Many of the CCs had multiple STs and spa types and, based on the immune evasion cluster type, isolates within a CC could be classified into different strains harboring a range of virulence and resistance genes. Phylogenetic analyses of the isolates showed most CCs were represented by one clade. The blaZ gene was identified in 45 (9.6%) PSSA. Although multiclonal, approximately 50% of blaZ-positive PSSA were from CC15 and were found to be genetically distant from the blaZ-negative CC15 PSSA. The broth microdilution, Etest® and cefinase, performed poorly; however, when the appearance of the zone edge was considered; as per the EUCAST and CLSI criteria, disc diffusion detected 100% of blaZ-positive PSSA. CONCLUSIONS: In Australia, PSSA bacteremia is not caused by the expansion of a single clone. Approximately 10% of S. aureus classified as penicillin-susceptible by the Vitek® 2 harbored blaZ. Consequently, we recommend that confirmation of Vitek® 2 PSSA be performed using an alternative method, such as disc diffusion with careful interpretation of the zone edge.
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    Prevalence of chronic non-communicable diseases in Ethiopia: A systematic review and meta-analysis of evidence.
    Tesfay, FH ; Zorbas, C ; Alston, L ; Backholer, K ; Bowe, SJ ; Bennett, CM (Frontiers Media SA, 2022)
    BACKGROUND: Non-communicable diseases (NCDs) are a growing global health challenge disproportionately impacting low- and middle-income settings, including Ethiopia. Currently, the body of evidence describing the burden of NCDs is fragmented, inconsistent, health facility- or institution-based, and out-dated in Ethiopia. We conducted a systematic review of the literature and meta-analysis of the prevalence of NCDs in community settings in Ethiopia. REVIEW METHODOLOGY: Community-based quantitative studies published in English between January 1st, 2012, and June 30th, 2022, that reported on the prevalence of NCDs in Ethiopia were included. A systematic search of Medline, Embase, Scopus, CINAHL, and Global Health using pretested search terms related to NCDs was conducted, and data were extracted using a piloted data extraction proforma adapted from the Joanna Briggs Institute tool. Meta-analysis was performed using Stata 16. While the pooled prevalence of Diabetes Mellitus (DM) and undiagnosed (DM) was computed and presented using forest plots, then overall prevalence of NCDs and other various types of NCDs were narratively synthesized. I 2 was used to assess heterogeneity. Studies that did not fulfill the criteria (used similar tool to measure the types of NCDs) for meta-analysis were narratively synthesized. RESULTS: Twenty-two studies met the inclusion criteria. Five studies measured the prevalence of NCDs (all NCDs together), ranging from 29 to 35% (prevalence estimates not pooled). The pooled prevalence of Diabetes Mellitus (DM) across ten studies was 5% (95% CI: 4-7%). Three studies each reported on the prevalence of undiagnosed DM (pooled prevalence 5%, 95% CI: 4-7%) and pre-DM (pooled prevalence 7%, 95% CI: 3-14%%). In a narrative analysis the prevalence of cardiovascular conditions ranged from 13.4 to 32.2% (n = 3 studies), cancer mortality ranged from 4 to 18% (n = 3 studies) and respiratory conditions ranged from 1 to 18% (n = 3 studies). Some studies have determined more than one NCDs and that is why the total number of studies are exceeding more than twenty studies. CONCLUSION AND RECOMMENDATIONS: Our analysis found that approximately one-third of Ethiopians have an NCD, with cardiovascular diseases the most common of all NCDs. The prevalence of respiratory conditions also appears high, but there are insufficient data for a pooled estimate. Whilst the prevalence of DM appears relatively low, there is evidence that the magnitude is increasing. Public health actions to address the high burden of cardiovascular and respiratory diseases, as well as the increasing magnitude of DM in Ethiopia, must be prioritized. SYSTEMATIC REVIEW REGISTRATION: PROSPERO [CRD42020196815].
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    The Magnitude of NCD Risk Factors in Ethiopia: Meta-Analysis and Systematic Review of Evidence.
    Tesfay, FH ; Backholer, K ; Zorbas, C ; Bowe, SJ ; Alston, L ; Bennett, CM (MDPI AG, 2022-04-27)
    BACKGROUND: Non-communicable Diseases (NCDs) and their risk factors are the leading contributors to morbidity and mortality globally, particularly in low- and middle-income countries including Ethiopia. To date, there has been no synthesis of the literature on the relative prevalence of NCD risk factors in Ethiopia. METHODOLOGY: We conducted a systematic review and meta-analysis of primary studies reporting on the prevalence of NCD risk factors in Ethiopia published in English from 2012 to July 2020. Pre-tested NCD search terms were applied to Medline, Embase, Scopus, CINAHL, and Global Health. Three reviewers screened and appraised the quality of the identified papers. Data extraction was conducted using a pilot tested proforma. Meta-analysis was conducted using Stata 16 and pooled prevalence estimated with associated 95% confidence intervals. Clinically heterogeneous studies that did not fulfil the eligibility criteria for meta-analysis were narratively synthesised. I2 was used to assess statistical heterogeneity. RESULTS: 47 studies fulfilled the inclusion criteria and contributed 68 NCD risk factor prevalence estimates. Hypertension was the most frequently examined NCD risk factor, with a pooled prevalence of 21% (n = 27 studies). The pooled prevalence percentages for overweight and obesity were 19.2% and 10.3%, respectively (n = 7 studies each), with a combined prevalence of 26.8% (n = 1 study). It was not possible to pool the prevalence of alcohol consumption, smoking, metabolic disorders, or fruit consumption because of heterogeneity across studies. The prevalence of alcohol use, as reported from the included individual studies, ranged from 12.4% to 13.5% (n = 7 studies). More than 90% of participants met the WHO-recommended level of physical activity (n = 5 studies). The prevalence of smoking was highly variable, ranging between 0.8% and 38.6%, as was the prevalence of heavy alcohol drinking (12.4% to 21.1%, n = 6 studies) and metabolic syndrome (4.8% to 9.6%, n = 5 studies). Fruit consumption ranged from 1.5% up to the recommended level, but varied across geographic areas (n = 3 studies). CONCLUSION AND RECOMMENDATIONS: The prevalence of NCD risk factors in Ethiopia is relatively high. National NCD risk factor surveillance is required to inform the prioritisation of policies and interventions to reduce the NCD burden in Ethiopia.
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    Random amplified polymorphic DNA analysis reveals no clear link between Staphylococcus epidermidis and acute mastitis
    Cullinane, M ; Scofield, L ; Murray, GL ; Payne, MS ; Bennett, CM ; Garland, SM ; Amir, LH (WILEY, 2022-08)
    Mastitis is commonly experienced by breastfeeding women. While Staphylococcus aureus is usually implicated in infectious mastitis, coagulase-negative staphylococci (CoNS) are a possible alternative pathogen. This case-control study examined the role of CoNS in mastitis using isolates cultured from breast milk of 20 women with mastitis and 16 women without mastitis. Gene sequencing determined bacterial species, and random amplified polymorphic DNA (RAPD) analysis investigated strain-level variation. The majority of CoNS isolates were Staphylococcus epidermidis (182/199; 91%). RAPD analysis identified 33 unique S. epidermidis profiles, with no specific profile associated with mastitis cases.
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    Premature mortality attributable to COVID-19: potential years of life lost in 17 countries around the world, January-August 2020.
    Ugarte, MP ; Achilleos, S ; Quattrocchi, A ; Gabel, J ; Kolokotroni, O ; Constantinou, C ; Nicolaou, N ; Rodriguez-Llanes, JM ; Huang, Q ; Verstiuk, O ; Pidmurniak, N ; Tao, JW ; Burström, B ; Klepac, P ; Erzen, I ; Chong, M ; Barron, M ; Hagen, TP ; Kalmatayeva, Z ; Davletov, K ; Zucker, I ; Kaufman, Z ; Kereselidze, M ; Kandelaki, L ; Le Meur, N ; Goldsmith, L ; Critchley, JA ; Pinilla, MA ; Jaramillo, GI ; Teixeira, D ; Goméz, LF ; Lobato, J ; Araújo, C ; Cuthbertson, J ; Bennett, CM ; Polemitis, A ; Charalambous, A ; Demetriou, CA ; C-MOR consortium, (Springer Science and Business Media LLC, 2022-01-09)
    BACKGROUND: Understanding the impact of the burden of COVID-19 is key to successfully navigating the COVID-19 pandemic. As part of a larger investigation on COVID-19 mortality impact, this study aims to estimate the Potential Years of Life Lost (PYLL) in 17 countries and territories across the world (Australia, Brazil, Cape Verde, Colombia, Cyprus, France, Georgia, Israel, Kazakhstan, Peru, Norway, England & Wales, Scotland, Slovenia, Sweden, Ukraine, and the United States [USA]). METHODS: Age- and sex-specific COVID-19 death numbers from primary national sources were collected by an international research consortium. The study period was established based on the availability of data from the inception of the pandemic to the end of August 2020. The PYLL for each country were computed using 80 years as the maximum life expectancy. RESULTS: As of August 2020, 442,677 (range: 18-185,083) deaths attributed to COVID-19 were recorded in 17 countries which translated to 4,210,654 (range: 112-1,554,225) PYLL. The average PYLL per death was 8.7 years, with substantial variation ranging from 2.7 years in Australia to 19.3 PYLL in Ukraine. North and South American countries as well as England & Wales, Scotland and Sweden experienced the highest PYLL per 100,000 population; whereas Australia, Slovenia and Georgia experienced the lowest. Overall, males experienced higher PYLL rate and higher PYLL per death than females. In most countries, most of the PYLL were observed for people aged over 60 or 65 years, irrespective of sex. Yet, Brazil, Cape Verde, Colombia, Israel, Peru, Scotland, Ukraine, and the USA concentrated most PYLL in younger age groups. CONCLUSIONS: Our results highlight the role of PYLL as a tool to understand the impact of COVID-19 on demographic groups within and across countries, guiding preventive measures to protect these groups under the ongoing pandemic. Continuous monitoring of PYLL is therefore needed to better understand the burden of COVID-19 in terms of premature mortality.
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    Age at onset and persistence of eczema are related to subsequent risk of asthma and hay fever from birth to 18 years of age
    Lowe, AJ ; Angelica, B ; Su, J ; Lodge, CJ ; Hill, DJ ; Erbas, B ; Bennett, CM ; Gurrin, LC ; Axelrad, C ; Abramson, MJ ; Allen, KJ ; Dharmage, SC (WILEY, 2017-06)
    BACKGROUND: Few studies have simultaneously addressed the importance of age of onset and persistence of eczema for the subsequent development of asthma and hay fever, particularly into early adulthood. METHODS: A high-risk birth cohort was recruited comprising 620 infants, who were then followed up frequently until 2 years of age, annually from age 3 to 7, then at 12 and 18 years, to document any episodes of eczema, current asthma, and hay fever. The generalized estimation equation technique was used to examine asthma and hay fever outcomes at 6 (n = 325), 12 (n = 248) and 18 (n = 240) years, when there was consistency of associations across the follow-ups. RESULTS: Very early-onset persistent (onset <6 months, still present from 2 to 5 years) eczema was related to current asthma (adjusted OR = 3.2 [95% CI = 1.7-6.1]), as was very early-onset remitting eczema (onset <6 months but not present from 2-5 years, OR = 2.7, 95% CI = 1.0-7.2) and early-onset persistent eczema (onset from 6-24 months, OR = 2.3, 95% CI = 1.2-4.7). Late-onset eczema (commenced from 2-5 years) was associated with increased risk of asthma at 12 years (OR = 3.0, 95% CI=1.1-8.2) but not at age 6 years. Only very early-onset persistent eczema was associated with increased risk of hay fever (aOR = 2.4, 95% CI = 1.4-4.1). CONCLUSION AND CLINICAL RELEVANCE: Eczema which commences in early infancy and persists into toddler years is strongly associated with asthma, and to a lesser extent hay fever, in high-risk children. If these associations are causal, prevention of early-life eczema might reduce the risk of respiratory allergy.
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    Learning to live with COVID-19 in Australia: time for a new approach
    Bennett, CM (SAX INST, 2021-09)
    The emergence of the Delta variant of SARS-CoV-2 has made Australia's 'COVID-zero' strategy unviable. As signalled by the Australian Government's National plan to transition Australia's national COVID-19 response, we need to plan a pathway forward for life beyond lockdown. However, this plan must be guided by long overdue discussions on our tolerance for serious illness, and hospital and intensive care unit capacity. The modelling that informs the national transition plan remains relevant, even with increases in case numbers, but one crucial thing that does change if cases continue to escalate is the effectiveness of test, trace and isolate models. As we move into suppression mode with higher rates of the population fully vaccinated, we will no longer need to find every case. This is among the many shifts in approach that will shape our transition by early 2022 to living with - and controlling - the disease.