A nationwide population-based study of Escherichia coli bloodstream infections: incidence, antimicrobial resistance and mortality

Epidemiology of invasive Escherichia coli disease in adults in England, 2013-2017

Extraintestinal pathogenic Escherichia coli (ExPEC) causes invasive E. coli disease (IED), including bacteraemia and (uro)sepsis, resulting in a high disease burden, especially among older adults. This study describes the epidemiology of IED in England (2013-2017) by combining laboratory surveillance and clinical data. A total of 191 612 IED cases were identified. IED incidence increased annually by 4.4-8.2% across all ages and 2.8-7.6% among adults ≥60 years of age. When laboratory-confirmed urosepsis cases without a positive blood culture were included, IED incidence in 2017 reached 149.4/100 000 person-years among all adults and 368.4/100 000 person-years among adults ≥60 years of age. Laboratory-confirmed IED cases were identified through E. coli-positive blood samples (55.3%), other sterile site samples (26.3%), and urine samples (16.6%), with similar proportions observed among adults ≥60 years of age. IED-associated case fatality rates ranged between 11.8-13.2% among all adults and 13.1-14.7% among adults ≥60 years of age. This study reflects the findings of other published studies and demonstrates IED constitutes a major and growing global health concern disproportionately affecting the older adult population. The high case fatality rates observed despite available antibiotic treatments emphasize the growing urgency for effective intervention strategies. The burden of urosepsis due to E. coli is likely underestimated and requires additional investigation.

Residence-colonization trade-off and niche differentiation enable coexistence of Escherichia coli phylogroups in healthy humans

Despite abundant literature on pathogenicity and virulence of the opportunistic pathogen Escherichia coli, much less is known about its ecological and evolutionary dynamics as a commensal. Based on two detailed longitudinal datasets on the gut microbiota of healthy adults followed for months to years in France and the USA, we identified a robust trade-off between the ability to establish in a new host (colonization) and to remain in the host (residence). Major E. coli lineages (phylogroups or subgroups) exhibited similar fitness but diverse strategies, from strong colonisers residing few days in the gut to poor colonisers residing for years. Strains with the largest number of extra-intestinal virulence associated genes and highest pathogenicity also resided for longest in hosts. Furthermore, the residence of a strain was more strongly reduced when it competed with other strains from the same phylogroup than from another phylogroup, suggesting niche differentiation between phylogroups. Based on a discrete-state Markov model developed to describe E. coli dynamics in a host population, we found that the trade-off and niche differentiation acted together as equalizing and stabilizing mechanisms allowing phylogroups to coexist over long periods of time. Our model also predicted that external disturbances may disproportionately affect resident strains, such as the extraintestinal pathogenic ones of subgroup B2.3. Our results call for further studies outside high-income countries, where the prevalence of this phylogroup is much lower. More generally, the trade-off between colonization and persistence could play a role in the diversification of other bacterial species of the microbiome.

Strain phylogroup and environmental constraints shape Escherichia coli dynamics and diversity over a 20-year human gut time series

Escherichia coli is an increasingly antibiotic-resistant opportunistic pathogen. Few data are available on its ecological and evolutionary dynamics in its primary commensal niche, the vertebrate gut. Using Illumina and/or Nanopore technologies, we sequenced whole genomes of 210 E. coli isolates from 22 stools sampled during a 20-year period from a healthy man (ED) living in Paris, France. All phylogroups, except C, were represented, with a predominance of B2 (34.3%), followed by A and F (19% each) phylogroups. Thirty-five clones were identified based on their haplogroup and pairwise genomic single nucleotide polymorphism distance and classified in three phenotypes according to their abundance and residence time: 25 sub-dominant/transient (52 isolates), five dominant/transient (48 isolates) and five dominant/resident (110 isolates). Four over five dominant/resident clones belonged to B2 and closely related F phylogroups, whereas sub-dominant/transient clones belonged mainly to B1, A and D phylogroups. The long residence times of B2 clones seemed to be counterbalanced by lower colonization abilities. Clones with larger within-host frequency persisted for longer. By comparing ED strain genomes to a collection of commensal E. coli genomes from 359 French individuals, we identified ED-specific genomic properties including an enrichment in genes involved in a metabolic pathway (mhp cluster) and the presence of a very rare antiviral defense island. The E. coli colonization within the gut microbiota was shaped by both the intrinsic properties of the strain lineages, in particular longer residence of phylogroup B2, and the environmental constraints such as diet or phages.

Mandatory surveillance of bacteremia conducted by automated monitoring

Except for a few countries, comprehensive all-cause surveillance for bacteremia is not part of mandatory routine public health surveillance. We argue that time has come to include automated surveillance for bacteremia in the national surveillance systems, and explore diverse approaches and challenges in establishing bacteremia monitoring. Assessed against proposed criteria, surveillance for bacteremia should be given high priority. This is based on severity, burden of illness, health gains obtained by improved treatment and prevention, risk of outbreaks (including health care associated infections), the emergence of antimicrobial drug resistance as well as the changing epidemiology of bacteremia which is seen along with an aging population and advances in medical care. The establishment of comprehensive surveillance for bacteremia was until recently conceived as an insurmountable task. With computerized systems in clinical microbiology, surveillance by real-time data capture has become achievable. This calls for re-addressing the question of including bacteremia among the conditions under mandatory surveillance. Experiences from several countries, including Denmark, show that this is feasible. We propose enhanced international collaboration, legislative action, and funding to address the challenges and opportunities.

Evaluating the costs of Escherichia coli bloodstream infections: a population-based cohort study in a large metropolitan Canadian region

Objectives

We evaluated the costs of susceptible and resistant Escherichia coli bloodstream infections (BSIs) in adults. Secondary outcomes were the impact of BSI on length of stay (LOS), readmissions and death.

Methods

We examined a population-based retrospective cohort of blood cultures from 2011 to 2018 in Calgary, Canada, linked to microcosting and gross costing data. Propensity score matching was completed, and costs were compared between no BSI and E. coli BSI over 90 days using linear regression.

Results

A total of 4581 BSIs in 89 673 adults experienced E. coli bacteraemia during the study period. The mean cost of an E. coli BSI at 90 days was $39 072 (SD: $95 747) in adults. Ceftriaxone-resistant (CRO-R) E. coli, resistant to fluoroquinolones (FQ) and trimethoprim/sulfamethoxazole, compared with susceptible E. coli BSI resulted in the greatest mean cost at $53 899 and the highest odds of readmission, increased LOS, and death.

Conclusions

E. coli BSI is associated with substantial costs. Total cost differences were highest in those with CRO-R E. coli with resistance to FQ and trimethoprim/sulfamethoxazole. Over the study period, bacteraemia secondary to these strains alone, added over $9 million to costs for healthcare in the Calgary Zone.

Clinical presentation and antimicrobial resistance of invasive Escherichia coli disease in hospitalized older adults: a prospective multinational observational study

BACKGROUND

Clinical data characterizing invasive Escherichia coli disease (IED) are limited. We assessed the clinical presentation of IED and antimicrobial resistance (AMR) patterns of causative E. coli isolates in older adults.

METHODS

EXPECT-2 (NCT04117113) was a prospective, observational, multinational, hospital-based study conducted in patients with IED aged ≥ 60 years. IED was determined by the microbiological confirmation of E. coli from blood; or by the microbiological confirmation of E. coli from urine or an otherwise sterile body site in the presence of requisite criteria of systemic inflammatory response syndrome (SIRS), Sequential Organ Failure Assessment (SOFA), or quick SOFA (qSOFA). The primary outcomes were the clinical presentation of IED and AMR rates of E. coli isolates to clinically relevant antibiotics. Complications and in-hospital mortality were assessed through 28 days following IED diagnosis.

RESULTS

Of 240 enrolled patients, 80.4% had bacteremic and 19.6% had non-bacteremic IED. One-half of infections (50.4%) were community-acquired. The most common source of infection was the urinary tract (62.9%). Of 240 patients, 65.8% fulfilled ≥ 2 SIRS criteria, and 60.4% had a total SOFA score of ≥ 2. Investigator-diagnosed sepsis and septic shock were reported in 72.1% and 10.0% of patients, respectively. The most common complication was kidney dysfunction (12.9%). The overall in-hospital mortality was 4.6%. Of 299 E. coli isolates tested, the resistance rates were: 30.4% for trimethoprim-sulfamethoxazole, 24.1% for ciprofloxacin, 22.1% for levofloxacin, 16.4% for ceftriaxone, 5.7% for cefepime, and 4.3% for ceftazidime.

CONCLUSIONS

The clinical profile of identified IED cases was characterized by high rates of sepsis. IED was associated with high rates of AMR to clinically relevant antibiotics. The identification of IED can be optimized by using a combination of clinical criteria (SIRS, SOFA, or qSOFA) and culture results.

Bio-Responsive Sliver Peroxide-Nanocarrier Serves as Broad-Spectrum Metallo-β-lactamase Inhibitor for Combating Severe Pneumonia

Metallo-β-lactamases (MBLs) represent a prevalent resistance mechanism in Gram-negative bacteria, rendering last-line carbapenem-related antibiotics ineffective. Here, a bioresponsive sliver peroxide (Ag2 O2 )-based nanovesicle, named Ag2 O2 @BP-MT@MM, is developed as a broad-spectrum MBL inhibitor for combating MBL-producing bacterial pneumonia. Ag2 O2 nanoparticle is first orderly modified with bovine serum albumin and polydopamine to co-load meropenem (MER) and [5-(p-fluorophenyl)-2-ureido]-thiophene-3-carboxamide (TPCA-1) and then encapsulated with macrophage membrane (MM) aimed to target inflammatory lung tissue specifically. The resultant Ag2 O2 @BP-MT@MM effectively abrogates MBL activity by displacing the Zn2+ cofactor in MBLs with Ag+ and displays potent bactericidal and anti-inflammatory properties, specific targeting abilities, and great bioresponsive characteristics. After intravenous injection, the nanoparticles accumulate prominently at infection sites through MM-mediated targeting . Ag+ released from Ag2 O2 decomposition at the infection sites effectively inhibits MBL activity and overcomes the resistance of MBL-producing bacteria to MER, resulting in synergistic elimination of bacteria in conjunction with MER. In two murine infection models of NDM-1+ Klebsiella pneumoniae-induced severe pneumonia and NDM-1+ Escherichia coli-induced sepsis-related bacterial pneumonia, the nanoparticles significantly reduce bacterial loading, pro-inflammatory cytokine levels locally and systemically, and the recruitment and activation of neutrophils and macrophages. This innovative approach presents a promising new strategy for combating infections caused by MBL-producing carbapenem-resistant bacteria.

Integron distribution and relationship to antimicrobial resistance in E. coli isolated from blood culture

PURPOSE

The aim of this study was to evaluate the distribution of integrons in strains of E. coli isolated from blood culture and the relationship between integrons and antimicrobial resistance.

METHODS

The study included 100 E. coli strains sent to the Medical Microbiology Laboratory from different clinics between September 2022 and June 2023. Antibiotic susceptibility was evaluated according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The presence of integrons was determined by the inhouse polymerase chain reaction (PCR).

RESULTS

Integron positivity was detected in 45 (45%) of isolates, and class 1 integrons were found in 41 (41%), class 2 integrons in 2 (2%), and both class 1 integrons and class 2 integrons in 2 (2%). Class 3 integron positivity was not detected. In total, 63 cases of community origin and 37 cases of hospital origin were identified. When antibiotic resistance was evaluated, the highest sensitivity was noted for amikacin (1%), meropenem (5%), imipenem (6%), and the highest resistant antibiotics were ampicillin (82%), cepfuroxime sodium (65%), and amoxicillin/clavulanate (62%), respectively. Of the 16 antimicrobial substances evaluated, 10 had an antibiotic resistance rate of over 45%. In class 1 integron-positive samples, ampicillin resistance and trimethoprim/sulfamethoxazole resistance were higher than in negative samples (p = 0.02, p = 0.0001, respectively). Fifty-one (51%) samples were found to have multiple drug resistance (MDR). In total, 59.5% of hospital-acquired isolates and 46% of community-acquired isolates were considered to be MDR. The class 1 integron positivity in MDR samples was high (p = 0.038).

CONCLUSION

The high MDR rates in both hospital-acquired and community-acquired isolates are alarming. In particular, class 1 integron monitoring is very important to prevent the spread of MDR isolates.

Rapid Phenotypic Antibiotic Susceptibility Profiling of Clinical Escherichia coli and Klebsiella pneumoniae Blood Cultures

Bloodstream infections (BSI) are defined by the presence of viable bacteria or fungi, accompanied by systemic signs of infection. Choosing empirical therapy based solely on patient risk factors and prior antibiotic susceptibility test (AST) may lead to either ineffective treatment or unnecessarily broad-spectrum antibiotic exposure. In general, Clinical & Laboratory Standards Institute guideline-approved ASTs have a turnaround time of 48-72 h from sample to answer, a period that may result in a critical delay in the appropriate selection of therapy. Therefore, reducing the time required for AST is highly advantageous. We have previously shown that our novel rapid AST method, MAPt (Micro-Agar-PCR-test), accurately identifies susceptibility profiles for spiked bioterrorism agents like Bacillus anthracis, Yersinia pestis and Francisella tularensis directly from whole-blood and blood culture samples, even at low bacterial levels (500 CFU/mL). This study evaluated the performance of MAPt on routine bloodstream infection (BSI), focusing on Escherichia coli and Klebsiella pneumoniae isolates from clinical cultures, including resistant strains to some of the six tested antibiotics. Notably, MAPt yielded results exceeding 95% agreement with the standard hospital method within a significantly shorter timeframe of 6 h. These findings suggest significant potential for MAPt as a rapid and reliable BSI management tool.

Occurrence, Typing, and Resistance Genes of ESBL/AmpC-Producing Enterobacterales in Fresh Vegetables Purchased in Central Israel

Beta-lactam resistance can lead to increased mortality, higher healthcare expenses, and limited therapeutic options. The primary mechanism of beta-lactam resistance is the production of extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases. The spread of beta-lactamase-producing Enterobacterales via the food chain may create a resistance reservoir. The aims of this study were to determine the prevalence of ESBL/AmpC-producing Enterobacterales in vegetables, to examine the association between EBSL/AmpC-producing bacteria and types of vegetables, packaging, and markets, and to investigate the genetic features of ESBL-producing isolates. The antibiotic susceptibilities were determined using VITEK. Phenotypic ESBL/AmpC production was confirmed using disk diffusion. ESBL-producing isolates were subjected to Fourier-transform infrared (FT-IR) spectroscopy and to whole genome sequencing using Oxford Nanopore sequencing technology. Of the 301 vegetable samples, 20 (6.6%) were positive for ESBL producers (16 Klebsiella pneumoniae and 4 Escherichia coli), and 63 (20.9%) were positive for AmpC producers (56 Enterobacter cloacae complex, 4 Enterobacter aerogenes/cancerogenus, and 3 Pantoea spp., Aeromonas hydrophila, and Citrobacter braakii). The blaCTX-M and blaSHV genes were most common among ESBL-producing isolates. The beta-lactamase genes of the ESBL producers were mainly carried on plasmids. Multilocus sequence typing and FT-IR typing revealed high diversity among the ESBL producers. AmpC producers were significantly more common in leafy greens and ESBL producers were significantly less common in climbing vegetables. The presence of ESBL/AmpC-producing Enterobacterales in raw vegetables may contribute to the dissemination of resistance genes in the community.

Clinical burden of invasive Escherichia coli disease among older adult patients treated in hospitals in the United States

BACKGROUND

Invasive extraintestinal pathogenic Escherichia coli disease (IED) can lead to severe outcomes, particularly among older adults. However, the clinical burden of IED in the U.S. has not been well characterized.

METHODS

IED encounters among patients ≥ 60 years old were identified using the PINC AI™ Healthcare Database (10/01/2015-03/31/2020) by either a positive E. coli culture in blood or another normally sterile body site and ≥ 1 sign of systemic inflammatory response syndrome or signs of sepsis, or a positive E. coli culture in urine with urinary tract infection and signs of sepsis. Medical resource utilization, clinical outcomes, and E. coli isolate characteristics were descriptively reported during the first IED encounter and during the following year (observation period).

RESULTS

Overall, 19,773 patients with IED were included (mean age: 76.8 years; 67.4% female; 78.5% with signs of sepsis). Most encounters involved community-onset IED (94.3%) and required hospitalization (96.5%; mean duration: 6.9 days), with 32.4% of patients being admitted to the intensive care unit (mean duration: 3.7 days). Most E. coli isolates were resistant to ≥ 1 antibiotic category (61.7%) and 34.4% were resistant to ≥ 3 antibiotic categories. Following their first IED encounter, 34.8% of patients were transferred to a skilled nursing/intermediate care facility, whereas 6.8% had died. During the observation period, 36.8% of patients were rehospitalized, 2.4% had IED recurrence, and in-hospital death increased to 10.9%.

CONCLUSIONS

IED is associated with substantial clinical burden at first encounter with considerable long-term consequences. Findings demonstrate the need for increased IED awareness and highlight potential benefits of prevention.

Economic burden of invasive Escherichia coli disease among older adult patients treated in hospitals in the United States

BACKGROUND: Although invasive Escherichia coli disease (IED) can lead to severe clinical outcomes, little is known about the associated medical resource use and cost burden of IED in US hospitals. OBJECTIVE: To comprehensively describe medical resource use and costs associated with IED during the initial IED event and over the subsequent 12 months. METHODS: Patients aged 60 years or older with 1 or more IED encounters were identified from the PINC AI Healthcare US hospital database (October 1, 2015, to March 31, 2020). The index encounter was defined as the first encounter with a positive E coli culture in a normally sterile site (group 1 IED) or positive E coli culture in urine with signs of sepsis (group 2 IED). Encounters with a positive culture from other bacteria or fungal pathogens were excluded. Outcomes were descriptively reported between admission and discharge for the index encounter and more than 1 - year post-index discharge. Medical resource use and costs included inpatient admissions and outpatient hospital services; costs were reported from a hospital's perspective (ie, charged amount) in 2021 USD. RESULTS: A total of 19,773 patients were identified (group 1 IED = 51.8%; group 2 IED = 48.2%). Mean age was 76.8 years, 67.4% were female, and 82.1% were White. Most index encounters were community-onset (94.3%) and led to hospitalization (96.5%) (mean inpatient days = 6.9 days). During the 1 - year post-index, 36.8% of patients had 1 or more all-cause hospitalizations. Mean [median] total all-cause hospital costs (as captured through the PINC AI Healthcare database) amounted to $16,760 [$11,340] during the index encounter and $10,942 [$804] during the 1 - year post-index; these costs were higher in the presence of sepsis and multidrug resistance and among hospital-onset IED. CONCLUSIONS: IED is associated with a substantial medical resource use and economic burden both during the initial encounter and over the following year in older adults. This highlights the critical need and potential benefits of preventive measures that may reduce the incidence of IED and associated economic burden. DISCLOSURES: This study was funded by Janssen Global Services, LLC. Dr Hernandez-Pastor is an employee of Janssen Pharmaceutica NV. Dr Geurtsen is an employee of Janssen Vaccines & Prevention BV. Dr Baugh is an employee of Janssen Research & Development, LLC. Dr El Khoury is an employee of Janssen Global Services, LLC. Dr Kalu and Dr Krishnarajah are employees of Janssen Scientific Affairs, LLC. Dr Gauthier-Loiselle, Ms Bungay, and Mr Cloutier are employees of Analysis Group, Inc., a consulting company that provided paid consulting services to Janssen Global Services, LLC. Dr Saade received consultation and speaker fees from Janssen.

The bacterial genetic determinants of Escherichia coli capacity to cause bloodstream infections in humans

Escherichia coli is both a highly prevalent commensal and a major opportunistic pathogen causing bloodstream infections (BSI). A systematic analysis characterizing the genomic determinants of extra-intestinal pathogenic vs. commensal isolates in human populations, which could inform mechanisms of pathogenesis, diagnostic, prevention and treatment is still lacking. We used a collection of 912 BSI and 370 commensal E. coli isolates collected in France over a 17-year period (2000-2017). We compared their pangenomes, genetic backgrounds (phylogroups, STs, O groups), presence of virulence-associated genes (VAGs) and antimicrobial resistance genes, finding significant differences in all comparisons between commensal and BSI isolates. A machine learning linear model trained on all the genetic variants derived from the pangenome and controlling for population structure reveals similar differences in VAGs, discovers new variants associated with pathogenicity (capacity to cause BSI), and accurately classifies BSI vs. commensal strains. Pathogenicity is a highly heritable trait, with up to 69% of the variance explained by bacterial genetic variants. Lastly, complementing our commensal collection with an older collection from 1980, we predict that pathogenicity continuously increased through 1980, 2000, to 2010. Together our findings imply that E. coli exhibit substantial genetic variation contributing to the transition between commensalism and pathogenicity and that this species evolved towards higher pathogenicity.

Antimicrobial resistance and mortality following E. coli bacteremia

BACKGROUND

Global estimates suggest millions of deaths annually are associated with antimicrobial resistance (AMR) but these are generated from scarce data on the relative risk of death attributable to drug-resistant versus drug-sensitive infections.

METHODS

We examined all episodes of E. coli bloodstream infection in Ontario, Canada between 2017 and 2020, and measured 90 day mortality among those with resistant versus sensitive isolates for each of 8 commonly used antibiotic classes and a category of difficult to treat resistance (DTTR). We used multivariable logistic regression to calculate an adjusted odds of mortality associated with AMR, after accounting for patient demographics, comorbidities, and prior healthcare exposure.

FINDINGS

Among 14,548 eligible episodes of E. coli bloodstream infection, resistance was most common to aminopenicillins (46.8%), followed by first generation cephalosporins (38.8%), fluoroquinolones (26.5%), sulfonamides (24.1%), third generation cephalosporins (13.8%), aminoglycosides (11.7%), beta-lactam-beta-lactamase-inhibitors (9.1%) and carbapenems (0.2%). Only 18 (0.1%) episodes exhibited DTTR. For each antibiotic class, the unadjusted odds of mortality (OR) were higher among resistant isolates, but after accounting for patient characteristics the adjusted odds (aOR) of mortality were attenuated: aminopenicillins (OR 1.22, 95% CI 1.12-1.33; aOR 1.09, 95% CI 0.99-1.20), first generation cephalosporins (OR 1.24, 95% CI 1.14-1.35; aOR 1.07, 95% CI 0.97-1.18), third generation cephalosporins (OR 1.64, 95% CI 1.47-1.82; aOR 1.29, 95% CI 1.15-1.46), beta-lactam-beta-lactamase-inhibitors (OR 1.69, 95% CI 1.52-1.89, aOR 1.28, 95% CI 1.13-1.45), carbapenems (OR 3.11, 95% CI 1.52-6.34; aOR 2.06, 95% CI 0.91-4.66), sulfonamides (OR 1.19, 95% CI 1.07-1.31, aOR 1.06, 95% CI 0.95-1.18), fluoroquinolones (OR 1.49, 95% CI 1.36-1.64, aOR 1.16, 95% CI 1.05-1.29), aminoglycosides (OR 1.43, 95% CI 1.27-1.62; aOR 1.27, 95% CI 1.11-1.46), and DTTR (OR 3.71, 95% CI 1.46-9.41; aOR 2.58, 95% CI 0.87-7.66).

INTERPRETATION

AMR is associated with substantial increased mortality among patients with E. coli bloodstream infection, particularly for resistance to classes commonly used as empiric treatment. Surveillance for AMR-associated mortality should incorporate adjustment for patient characteristics and prior healthcare utilization.

FUNDING

This work was supported by a project grant from CIHR (grant number 159503). This study was also supported by ICES, which is funded by an annual grant from Ontario Ministry of Health and Long-Term Care (MOHLTC).

One-year mortality and years of potential life lost following bloodstream infection among adults: A nation-wide population based study

Background

Limited data exist on long-term consequences of bloodstream infections (BSIs). We aimed to examine incidence, 1-year mortality, and years of potential life lost (YPLL) following BSI. We estimated the relative contribution of hospital-onset BSI (HO-BSI) and antibiotic-resistant BSI to incidence, mortality and YPLL.

Methods

We used data from Israel's national BSI surveillance system (covering eight sentinel bacteria, comprising 70% of all BSIs) and the national death registry. Adults with BSI between January 2018 and December 2019 were included. The outcomes were all-cause 30-day and 1-year mortality, with no adjustment for co-morbidities. We calculated the age-standardized mortality rate and YPLL using the Global Burden of Disease reference population and life expectancy tables.

Findings

In total, 25,376 BSIs occurred over 2 years (mean adult population: 6,068,580). The annual incidence was 209·1 BSIs (95% CI 206·5–211·7) per 100,000 population. The case fatality rate was 25·6% (95% CI 25·0-26·2) at 30 days and 46·4% (95% CI 45·5-47·2) at 1 year. The hazard of death increased by 30% for each decade of age (HR=1·3 [95% CI 1·2-1·3]). The annual age-standardized mortality rate and YPLL per 100,000 were 50·8 (95% CI 49·7-51·9) and 1,012·6 (95% CI 986·9-1,038·3), respectively. HO-BSI (6,962 events) represented 27·4% (95% CI 26·9-28·0) of BSIs, 33·9% (95% CI 32·6-35·0) of deaths and 39·9% (95% CI 39·5-40·2) of YPLL. HO-BSI by drug-resistant bacteria (3,072 events) represented 12·1% (95% CI 11·7-12·5) of BSIs, 15·6% (95% CI 14·7-16·5) of deaths, and 18·4% (95% CI 18·1-18·7) of YPLL.

Interpretation

One-year mortality following BSI is high. The burden of BSI is similar to that of ischemic stroke. HO-BSI and drug-resistant BSI contribute disproportionately to BSI mortality and YPLL.

Funding

None.

Effect of temperature on Escherichia coli bloodstream infection in a nationwide population-based study of incidence and resistance

BACKGROUND

The incidence of Escherichia coli bloodstream infections (BSI) is high and increasing. We aimed to describe the effect of season and temperature on the incidence of E. coli BSI and antibiotic-resistant E. coli BSI and to determine differences by place of BSI onset.

METHODS

All E. coli BSI in adult Israeli residents between January 1, 2018 and December 19, 2019 were included. We used the national database of mandatory BSI reports and outdoor temperature data. Monthly incidence and resistance were studied using multivariable negative binomial regressions with season (July-October vs. other) and temperature as covariates.

RESULTS

We included 10,583 events, 9012 (85%) community onset (CO) and 1571 (15%) hospital onset (HO). For CO events, for each average monthly temperature increase of 5.5 °C, the monthly number of events increased by 6.2% (95% CI 1.6-11.1%, p = 0.008) and the monthly number of multidrug-resistant events increased by 4.9% (95% CI 0.3-9.7%, p = 0.04). The effect of season was not significant. For HO events, incidence of BSI and resistant BSI were not associated with temperature or season.

CONCLUSION

Temperature increases the incidence of CO E. coli BSI and CO antibiotic-resistant E. coli BSI. Global warming threatens to increase the incidence of E. coli BSI.