Mortality in Escherichia coli bloodstream infections: a multinational population-based cohort study.

BACKGROUND: Escherichia coli is the most common cause of bloodstream infections (BSIs) and mortality is an important aspect of burden of disease. Using a multinational population-based cohort of E. coli BSIs, our objectives were to evaluate 30-day case fatality risk and mortality rate, and determine factors associated with each. METHODS: During 2014-2018, we identified 30-day deaths from all incident E. coli BSIs from surveillance nationally in Finland, and regionally in Sweden (Skaraborg) and Canada (Calgary, Sherbrooke, western interior). We used a multivariable logistic regression model to estimate factors associated with 30-day case fatality risk. The explanatory variables considered for inclusion were year (2014-2018), region (five areas), age (< 70-years-old, ≥70-years-old), sex (female, male), third-generation cephalosporin (3GC) resistance (susceptible, resistant), and location of onset (community-onset, hospital-onset). The European Union 28-country 2018 population was used to directly age and sex standardize mortality rates. We used a multivariable Poisson model to estimate factors associated with mortality rate, and year, region, age and sex were considered for inclusion. RESULTS: From 38.7 million person-years of surveillance, we identified 2961 30-day deaths in 30,923 incident E. coli BSIs. The overall 30-day case fatality risk was 9.6% (2961/30923). Calgary, Skaraborg, and western interior had significantly increased odds of 30-day mortality compared to Finland. Hospital-onset and 3GC-resistant E. coli BSIs had significantly increased odds of mortality compared to community-onset and 3GC-susceptible. The significant association between age and odds of mortality varied with sex, and contrasts were used to interpret this interaction relationship. The overall standardized 30-day mortality rate was 8.5 deaths/100,000 person-years. Sherbrooke had a significantly lower 30-day mortality rate compared to Finland. Patients that were either ≥70-years-old or male both experienced significantly higher mortality rates than those < 70-years-old or female. CONCLUSIONS: In our study populations, region, age, and sex were significantly associated with both 30-day case fatality risk and mortality rate. Additionally, 3GC resistance and location of onset were significantly associated with 30-day case fatality risk. Escherichia coli BSIs caused a considerable burden of disease from 30-day mortality. When analyzing population-based mortality data, it is important to explore mortality through two lenses, mortality rate and case fatality risk.

COVID-19 and future pandemics: is isolation and social distancing the new norm?

The coronavirus, named SARS-CoV-2, is the cause of COVID-19. This virus spreads readily from person to person and predominantly to and from the respiratory route and through droplets. There are many different interventions that can be and are used to decrease successfully the risk and spread of COVID-19. Most of the principles underpinning these interventions relate to isolation and social distancing. These will need to be continued, at least in part, until safe and very effective vaccines become widely available and are delivered extensively and successfully globally. This new norm is isolation, plus social and physical distancing, and this new norm will likely be with us for some time to come. It will also be with us in any future pandemics, whether caused by bacteria or viruses, but especially when the causative pathogen spreads predominantly through the respiratory route. However, lockdowns and restrictions also cause many adverse but unintended economic, social and health consequences. Therefore, what is put into place needs to be proportionate to levels of risk of disease as well as spread, and which will vary in different localities and with time.

'Antibiotic footprint' as a communication tool to aid reduction of antibiotic consumption.

'Superbugs', bacteria that have become resistant to antibiotics, have been in numerous media headlines, raising awareness of antibiotic resistance and leading to multiple action plans from policymakers worldwide. However, many commonly used terms, such as 'the war against superbugs', risk misleading people to request 'new' or 'stronger' antibiotics from their doctors, veterinary surgeons or pharmacists, rather than addressing a fundamental issue: the misuse and overuse of antibiotics in humans and animals. Simple measures of antibiotic consumption are needed for mass communication. In this article, we describe the concept of the 'antibiotic footprint' as a tool to communicate to the public the magnitude of antibiotic use in humans, animals and industry, and how it could support the reduction of overuse and misuse of antibiotics worldwide. We propose that people need to make appropriate changes in behaviour that reduce their direct and indirect consumption of antibiotics.

Factors affecting the presence, genetic diversity and antimicrobial sensitivity of Escherichia coli in poultry meat samples collected from Canberra, Australia.

To investigate the factors determining the clonal composition of Escherichia coli in poultry meat samples, 306 samples were collected from 16 shops, representing three supermarket chains and an independent butchery located in each of the four town centers of Canberra, Australia, during the summer, autumn and winter. A total of 3415 E. coli isolates were recovered and assigned to a phylogenetic group using the Clermont quadruplex PCR method, fingerprinted using repetitive element palindromic (REP) PCR and screened for their antimicrobial susceptibility profiles. The probability of detecting E. coli and the number of fingerprint types detected per sample, as well as the phylogroup membership of the isolates and their antimicrobial sensitivity profiles varied, with one or more of retailer, store, meat type, season and husbandry. The results of this study demonstrate that poultry meat products are likely to be contaminated with a genetically diverse community of E. coli and suggest that factors relating to the nature of the meat product and distribution chain are determinants of the observed diversity.

World Health Organization Ranking of Antimicrobials According to Their Importance in Human Medicine: A Critical Step for Developing Risk Management Strategies to Control Antimicrobial Resistance From Food Animal Production.

Antimicrobial use in food animals selects for antimicrobial resistance in bacteria, which can spread to people. Reducing use of antimicrobials-particularly those deemed to be critically important for human medicine-in food production animals continues to be an important step for preserving the benefits of these antimicrobials for people. The World Health Organization ranking of antimicrobials according to their relative importance in human medicine was recently updated. Antimicrobials considered the highest priority among the critically important antimicrobials were quinolones, third- and fourth-generation cephalosporins, macrolides and ketolides, and glycopeptides. The updated ranking allows stakeholders in the agriculture sector and regulatory agencies to focus risk management efforts on drugs used in food animals that are the most important to human medicine. In particular, the current large-scale use of fluoroquinolones, macrolides, and third-generation cephalosporins and any potential use of glycopeptides and carbapenems need to be addressed urgently.

Phylogenetic diversity, antimicrobial susceptibility and virulence characteristics of phylogroup F Escherichia coli in Australia.

Unlike Escherichia coli strains belonging to phylogroup B2, the clinical significance of strains belonging to phylogroup F is not well understood. Here we report on a collection of phylogroup F strains recovered in Australia from faeces and extra-intestinal sites from humans, companion animals and native animals, as well as from poultry meat and water samples. The distribution of sequence types was clearly non-random with respect to isolate source. The antimicrobial resistance and virulence trait profiles also varied with the sequence type of the isolate. Phylogroup F strains tended to lack the virulence traits typically associated with phylogroup B2 strains responsible for extra-intestinal infection in humans. Resistance to fluoroquinolones and/or expanded-spectrum cephalosporins was common within ST648, ST354 and ST3711. Although ST354 and ST3711 are part of the same clonal complex, the ST3711 isolates were only recovered from native birds being cared for in a single wildlife rehabilitation centre, whereas the ST354 isolates were from faeces and extra-intestinal sites of dogs and humans, as well as from poultry meat. Although ST354 isolates from chicken meat in Western Australia were distinct from all other ST354 isolates, those from poultry meat samples collected in eastern Australia shared many similarities with other ST354 isolates from humans and companion animals.

Does Lyme disease exist in Australia?

There is no convincing evidence that classic Lyme disease occurs in Australia, nor is there evidence that the causative agent, Borrelia burgdorferi, is found in Australian animals or ticks. Lyme disease, however, can be acquired overseas but diagnosed in Australia; most people presenting with laboratory-confirmed Lyme disease in Australia were infected in Europe. Despite the lack of evidence that Lyme disease can be acquired in Australia, growing numbers of patients, their supporters, and some politicians demand diagnoses and treatment according to the protocols of the "chronic Lyme disease" school of thought. Antibiotic therapy for chronic "Lyme disease-like illness" can cause harm to both the individual (eg, cannula-related intravenous sepsis) and the broader community (increased antimicrobial resistance rates). Until there is strong evidence from well performed clinical studies that bacteria present in Australia cause a chronic debilitating illness that responds to prolonged antibiotics, treating patients with "Lyme disease-like illness" with prolonged antibiotic therapy is unjustified, and is likely to do much more harm than good.

Australian Group on Antimicrobial Resistance Australian Staphylococcus aureus Sepsis Outcome Programme annual report, 2014.

From 1 January to 31 December 2014, 27 institutions around Australia participated in the Australian Staphylococcal Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2014 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin and to characterise the molecular epidemiology of the isolates. Overall, 18.8% of the 2,206 SAB episodes were methicillin resistant, which was significantly higher than that reported in most European countries. The 30-day all-cause mortality associated with methicillin-resistant SAB was 23.4%, which was significantly higher than the 14.4% mortality associated with methicillin-sensitive SAB (P <0.0001). With the exception of the beta-lactams and erythromycin, antimicrobial resistance in methicillin-sensitive S. aureus remains rare. However in addition to the beta-lactams, approximately 50‰ of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approximately 15% were resistant to co-trimoxazole, tetracycline and gentamicin. When applying the European Committee on Antimicrobial Susceptibility Testing breakpoints, teicoplanin resistance was detected in 2 S. aureus isolates. Resistance was not detected for vancomycin or linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to 2 healthcare-associated MRSA clones; ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) has become the predominant healthcare associated clone in Australia. Sixty per cent of methicillin-resistant SAB were due to community-associated (CA) clones. Although polyclonal, almost 44% of community-associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA) and ST1-IV [2B] (WA1). CA-MRSA, in particular the ST45-V [5C2&5] (WA84) clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. As CA-MRSA is well established in the Australian community it is important that antimicrobial resistance patterns in community and healthcare-associated SAB is monitored as this information will guide therapeutic practices in treating S. aureus sepsis.

A major reduction in hospital-onset Staphylococcus aureus bacteremia in Australia-12 years of progress: an observational study.

BACKGROUND: Staphylococcus aureus bacteremia (SAB) is a serious cause of morbidity and mortality. This longitudinal study describes significant reductions in hospital-onset SAB (HO-SAB) in Australian hospitals over the past 12 years. METHODS: An observational cohort study design was used. Prospective surveillance of HO-SAB in 132 hospitals in Australia was undertaken. Aggregated data from all patients who acquired HO-SAB was collected (defined as 1 or more blood cultures positive for S. aureus taken from a patient who had been admitted to hospital for >48 hours). The primary outcome was the incidence of HO-SAB, including both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) S. aureus strains. RESULTS: A total of 2733 HO-SAB cases were identified over the study period, giving an aggregate incidence of 0.90 per 10 000 patient-days (PDs) (95% confidence interval [CI], .86-.93). There was a 63% decrease in the annual incidence, from 1.72 per 10 000 PDs in 2002 (95% CI, 1.50-1.97) to 0.64 per 10 000 PDs (95% CI, .53-.76) in 2013. The mean reduction per year was 9.4% (95% CI, -8.1% to -10.7%). Significant reductions in both HO-MRSA (from 0.77 to 0.18 per 10 000 PDs) and HO-MSSA (from 1.71 to 0.64 per 10 000 PDs) bacteremia were observed. CONCLUSIONS: There was a major and significant reduction in incidence of HO-SAB caused by both MRSA and MSSA in Australian hospitals since 2002. This reduction coincided with a range of infection prevention and control activities implemented during this time. It suggests that national and local efforts to reduce the burden of healthcare-associated infections have been very successful.

The importance of a One Health approach to preventing the development and spread of antibiotic resistance.

Antibiotic resistance is a continuing and growing problem. Antibiotic resistance causes increased deaths, complications, expenses and prolonged hospital stays. There are not likely to be many new classes of antibiotics becoming available in the next few decades. We need to take a "One Health" perspective to this problem. We need to preserve the usefulness of those antibiotics we currently have by decreasing their overall use in all sectors, and especially the use of broad spectrum agents. We also need to improve our ability to prevent infections and the spread of resistant bacteria wherever they arise or are found. This means improving our practices with infection control, hygiene and animal husbandry. We need to improve the development and the delivery of effective and safe vaccines to prevent infections. We need safe water supplies. Our failure to do this has already resulted in large numbers of people entering a "post-antibiotic era" for many common infections.

Community-onset Staphylococcus aureus Surveillance Programme annual report, 2012.

In 2012, the Australian Group on Antimicrobial Resistance (AGAR) conducted a community-onset period-prevalence survey of clinical Staphylococcus aureus isolated from hospital outpatients and general practice patients including nursing homes, long term care facilities and hospice patients. Day surgery and dialysis patients were excluded. Twenty-nine medical microbiology laboratories from all state and mainland territories participated. Isolates were tested by Vitek2® (AST-P612 card). Results were compared with previous AGAR community surveys. Nationally, the proportion of S. aureus that were methicillin-resistant S. aureus (MRSA) increased significantly from 11.5% in 2000 to 17.9% in 2012 (P<0.0001). Resistance to the non-ß-lactam antimicrobials varied between regions. No resistance was detected to vancomycin, teicoplanin or linezolid. Resistance in methicillin susceptible S. aureus was rare apart from erythromycin (12.8%) and was absent for vancomycin, teicoplanin, linezolid and daptomycin. The proportion of S. aureus characterised as health care-associated MRSA (HA-MRSA) was 5.1%. Three HA-MRSA clones were characterised, with 72.9% and 26.4% of HA-MRSA classified as ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA) respectively. Multi-clonal community-associated MRSA (CA-MRSA) accounted for 12.5% of all S. aureus. Regional variation in resistance in MRSA was primarily due to the differential distribution of the 2 major HA-MRSA clones; ST239-III [3A] (Aus-2/3 EMRSA), which is resistant to multiple non-ß-lactam antimicrobials, and ST22-IV [2B] (EMRSA-15), which is resistant to ciprofloxacin and typically erythromycin. Although the majority of CA-MRSA were non-multi-resistant, a significant expansion of Panton-Valentine leukocidin (PVL) positive CA-MRSA clones has occurred nationally. The mean age of patients (31.7 years, 95% CI 28.9-34.5) with a PVL positive CA-MRSA infection was significantly lower (P<0.0001), than the mean age of patients with a PVL negative CA-MRSA infection (55.7 years, 95% CI 50.7-60.6). This shift in the molecular epidemiology of MRSA clones in the Australian community will potentially increase the number of young Australians with skin and soft tissue infections requiring hospitalisation.

Australian Staphylococcus aureus Sepsis Outcome Programme annual report, 2013.

From 1 January to 31 December 2013, around Australia 26 institutions around Australia participated in the Australian Staphylococcal Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2013 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, (with particular emphasis on susceptibility to methicillin) and to characterise the molecular epidemiology of the isolates. Overall 19.1% of the 2,010 SAB episodes were methicillin resistant, which is significantly higher than that reported in most European countries. Although the SAB 30-day all cause mortality appears to be decreasing in Australia, methicillin-resistant SAB associated mortality remains high (20.1%) and was significantly higher than methicillin-sensitive SAB associated mortality (13%) (P< 0.0001). With the exception of the ß-lactams and erythromycin, antimicrobial resistance in methicillin sensitive S. aureus remains rare. However, in addition to the ß-lactams, approximately 50% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approximately 20% were resistant to co-trimoxazole, tetracycline and gentamicin. Linezolid, daptomycin and teicoplanin resistance was detected in a small number of S. aureus isolates. Resistance to vancomycin was not detected. Resistance was largely attributable to 2 healthcare associated MRSA clones; ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) has now become the predominant healthcare associated clone in Australia. Approximately 60% of methicillin-resistant SAB were due to community associated clones. Although polyclonal, almost 50% of community associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA) and ST1-IV [2B] (WA1). CA-MRSA, in particular the ST45-V [5C2&5] (WA84) clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. As CA-MRSA is well established in the Australian community, it is important antimicrobial resistance patterns in community and healthcare associated SAB is monitored as this information will guide therapeutic practices in treating S. aureus sepsis.

COVID-19 restrictions limited interactions of people and resulted in lowered E. coli antimicrobial resistance rates.

Background: Antibiotic resistance is rising globally and is a major One Health problem. How much person-to-person transmission or 'contagion' contributes to the spread of resistant strains compared with antibiotic usage remains unclear. As part of its COVID-19 response, Australia introduced strict people movement restrictions in early 2020. Along with internal lockdown measures, movement of people into Australia from overseas was severely restricted. These circumstances provided a unique opportunity to examine the association of people movements with changes in resistance rates. Methods: Monthly resistance data on over 646 000 Escherichia coli urine isolates from 2016 till 2023 were modelled for statistical changes in resistance trends during pre-lockdown, lockdown and post-lockdown periods. Data were available for three clinical contexts (community, hospital and aged-care facilities). Data were also available for antibiotic usage volumes and movements of people into Australia. Results: In 2020, arrivals into Australia decreased by >95%. Antibiotic community use fell by >20%. There were sharp falls in trend rates of resistance for all antibiotics examined after restrictions were instituted. This fall in trend rates of resistance persisted during restrictions. Notably, trend rates of resistance fell in all three clinical contexts. After removal of restrictions, an upsurge in trend rates of resistance was seen for nearly all antibiotics but with no matching upsurge in antibiotic use. Conclusions: Restricting the movement of people appeared to have a dramatic effect on resistance rates in E. coli. The resulting reduced person-to-person interactions seems more closely associated with changes in antibiotic resistance than antibiotic usage patterns.

Panel stacking is a threat to consensus statement validity.

Consensus statements can be very influential in medicine and public health. Some of these statements use systematic evidence synthesis but others fail on this front. Many consensus statements use panels of experts to deduce perceived consensus through Delphi processes. We argue that stacking of panel members toward one particular position or narrative is a major threat, especially in absence of systematic evidence review. Stacking may involve financial conflicts of interest, but nonfinancial conflicts of strong advocacy can also cause major bias. Given their emerging importance, we describe here how such consensus statements may be misleading, by analyzing in depth a recent high-impact Delphi consensus statement on COVID-19 recommendations as a case example. We demonstrate that many of the selected panel members and at least 35% of the core panel members had advocated toward COVID-19 elimination (Zero-COVID) during the pandemic and were leading members of aggressive advocacy groups. These advocacy conflicts were not declared in the Delphi consensus publication, with rare exceptions. Therefore, we propose that consensus statements should always require rigorous evidence synthesis and maximal transparency on potential biases toward advocacy or lobbyist groups to be valid. While advocacy can have many important functions, its biased impact on consensus panels should be carefully avoided.

The scourge of antibiotic resistance: the important role of the environment.

Antibiotic resistance and associated genes are ubiquitous and ancient, with most genes that encode resistance in human pathogens having originated in bacteria from the natural environment (eg, ß-lactamases and fluoroquinolones resistance genes, such as qnr). The rapid evolution and spread of "new" antibiotic resistance genes has been enhanced by modern human activity and its influence on the environmental resistome. This highlights the importance of including the role of the environmental vectors, such as bacterial genetic diversity within soil and water, in resistance risk management. We need to take more steps to decrease the spread of resistance genes in environmental bacteria into human pathogens, to decrease the spread of resistant bacteria to people and animals via foodstuffs, wastes and water, and to minimize the levels of antibiotics and antibiotic-resistant bacteria introduced into the environment. Reducing this risk must include improved management of waste containing antibiotic residues and antibiotic-resistant microorganisms.

Australian Group on Antimicrobial Resistance Hospital-onset Staphylococcus aureus Surveillance Programme annual report, 2011.

In 2011, the Australian Group on Antimicrobial Resistance (AGAR) conducted a period-prevalence survey of clinical Staphylococcus aureus isolated from hospital inpatients. Twenty-nine microbiology laboratories from all states and mainland territories participated. Specimens were collected more than 48 hours post-admission. Isolates were tested by Vitek2® antimicrobial susceptibility card (AST-P612 card). Nationally, the proportion of S. aureus that were methicillin-resistant S. aureus (MRSA) was 30.3%; ranging from 19.9% in Western Australia to 36.8% in New South Wales/Australian Capital Territory. Resistance to the non-ß-lactam antimicrobials was common except for rifampicin, fusidic acid, high-level mupirocin and daptomycin. No resistance was detected for vancomycin, teicoplanin or linezolid. Antibiotic resistance in methicillin susceptible S. aureus (MSSA) was rare apart from erythromycin (13.2%) and there was no resistance to vancomycin, teicoplanin or linezolid. Inducible clindamycin resistance was the norm for erythromycin resistant, clindamycin intermediate/susceptible S. aureus in Australia with 90.6% of MRSA and 83.1% of MSSA with this phenotype having a positive double disc diffusion test (D-test). The proportion of S. aureus characterised as being healthcare-associated MRSA (HA-MRSA) was 18.2%, ranging from 4.5% in Western Australia to 28.0% in New South Wales/Australian Capital Territory. Four HA-MRSA clones were characterised and 98.8% of HA-MRSA isolates were classified as either ST22-IV [2B] (EMRSA-15) or ST239-III [3A] (Aus-2/3 EMRSA). Multiclonal community-associated MRSA (CA-MRSA) accounted for 11.7% of all S. aureus. In Australia, regional variation in resistance is due to the differential distribution of MRSA clones between regions, particularly for the major HA-MRSA clone, ST239-III [3A] (Aus-2/3 EMRSA), which is resistant to multiple non-ß-lactam antimicrobials.

Restricting access to antibiotics: The effectiveness of a 'no repeats' government policy intervention.

BACKGROUND: Australia has a high rate of antibiotic use. Government policy interventions are one strategy to optimise the use of antibiotics. On 1 April 2020, the Australian Government Department of Health introduced a policy intervention to increase the quality use of four antibiotics. OBJECTIVES: To assess if the government policy intervention improved the appropriate supply of the four antibiotics amoxicillin, amoxicillin-clavulanic acid, cefalexin and roxithromycin. METHOD: This study employed a retrospective cohort study design comparing a 10% sample (n = 345,018) of four antibiotics prescribed and dispensed in Australia during a three-month period (May, June, July) in 2019, and again in 2020 (after the policy intervention). The 10% sample of PBS data was obtained from the Australian Government Department of Health. Descriptive statistics, bivariate and multivariable logistic regression analysis were carried out. RESULTS: The results suggest the policy change improved the appropriate supply of original prescriptions in 2020 compared to 2019 OR = 1.75 (95% CI = 1.68-1.82, p < 0.001), and appropriate supply of repeat prescriptions OR = 1.56 (95% CI = 1.25-1.96, p < 0.001). In 2020, the proportion of appropriate supply of original prescriptions increased by an absolute difference of 1.8% (95% CI = 1.6-1.9%; P < 0.001), and appropriate supply of repeat prescriptions increased by 3.9% (95% CI = 2.2-5.5%; P < 0.001). The total number of antibiotic prescriptions prescribed and dispensed in 2019 (N = 219,960) reduced in 2020 (N = 125,058) after the policy intervention. CONCLUSION: The study provides evidence for the impact of a government policy intervention to improve the appropriate supply of antibiotics, although some of the reduction in antibiotic use was likely due to the concomitant COVID-19 pandemic. Further research is required to assess the impact of the intervention outside a pandemic.