Attributable mortality of infections caused by carbapenem-resistant Enterobacterales: results from a prospective, multinational case-control-control matched cohorts study (EURECA).

OBJECTIVES: To assess the mortality attributable to infections caused by carbapenem-resistant Enterobacterales (CRE) and to investigate the effect of clinical management on differences in observed outcomes in a multinational matched cohort study. METHODS: A prospective matched-cohorts study (NCT02709408) was performed in 50 European hospitals from March 2016 to November 2018. The main outcome was 30-day mortality with an active post-discharge follow-up when applied. The CRE cohort included patients with complicated urinary tract infections, complicated intra-abdominal infections, pneumonia, or bacteraemia from other sources because of CRE. Two control cohorts were selected: patients with infection caused by carbapenem-susceptible Enterobacterales (CSE) and patients without infection. Matching criteria included type of infection for the CSE group, hospital ward of CRE detection, and duration of hospital admission up to CRE detection. Multivariable and stratified Cox regression was applied. RESULTS: The cohorts included 235 patients with CRE infection, 235 patients with CSE infection, and 705 non-infected patients. The 30-day mortality (95% CI) was 23.8% (18.8-29.6), 10.6% (7.2-15.2), and 8.4% (6.5-10.6), respectively. The difference in 30-day mortality rates between patients with CRE infection when compared with patients with CSE infection was 13.2% (95% CI, 6.3-20.0), (HR, 2.57; 95% CI, 1.55-4.26; p < 0.001), and 15.4% (95% CI, 10.5-20.2) when compared with non-infected patients (HR, 3.85; 95% CI, 2.57-5.77; p < 0.001). The population attributable fraction for 30-day mortality for CRE vs. CSE was 19.28%, and for CRE vs. non-infected patients was 9.61%. After adjustment for baseline variables, the HRs for mortality were 1.87 (95% CI, 0.99-3.50; p 0.06) and 3.65 (95% CI, 2.29-5.82; p < 0.001), respectively. However, when treatment-related time-dependent variables were added, the HR of CRE vs. CSE reduced to 1.44 (95% CI, 0.78-2.67; p 0.24). DISCUSSION: CRE infections are associated with significant attributable mortality and increased adjusted hazard of mortality when compared with CSE infections or patients without infection. Underlying patient characteristics and a delay in appropriate treatment play an important role in the CRE mortality.

Risk factors for infections caused by carbapenem-resistant Enterobacterales: an international matched case-control-control study (EURECA).

Background: Data on risk factors for carbapenem-resistant Enterobacterales (CRE) with wider applicability are needed to inform preventive measures and efficient design of randomised trials. Methods: An international matched case-control-control study was performed in 50 hospitals with high CRE incidence from March 2016 to November 2018 to investigate different aspects of infections caused by CRE (NCT02709408). Cases were patients with complicated urinary tract infection (cUTI), complicated intraabdominal (cIAI), pneumonia or bacteraemia from other sources (BSI-OS) due to CRE; control groups were patients with infection caused by carbapenem-susceptible Enterobacterales (CSE), and by non-infected patients, respectively. Matching criteria included type of infection for CSE group, ward and duration of hospital admission. Conditional logistic regression was used to identify risk factors. Findings: Overall, 235 CRE case patients, 235 CSE controls and 705 non-infected controls were included. The CRE infections were cUTI (133, 56.7%), pneumonia (44, 18.7%), cIAI and BSI-OS (29, 12.3% each). Carbapenemase genes were found in 228 isolates: OXA-48/like, 112 (47.6%), KPC, 84 (35.7%), and metallo-ß-lactamases, 44 (18.7%); 13 produced two. The risk factors for CRE infection in both type of controls were (adjusted OR for CSE controls; 95% CI; p value) previous colonisation/infection by CRE (6.94; 2.74-15.53; <0.001), urinary catheter (1.78; 1.03-3.07; 0.038) and exposure to broad spectrum antibiotics, as categorical (2.20; 1.25-3.88; 0.006) and time-dependent (1.04 per day; 1.00-1.07; 0.014); chronic renal failure (2.81; 1.40-5.64; 0.004) and admission from home (0.44; 0.23-0.85; 0.014) were significant only for CSE controls. Subgroup analyses provided similar results. Interpretation: The main risk factors for CRE infections in hospitals with high incidence included previous colonization, urinary catheter and exposure to broad spectrum antibiotics. Funding: The study was funded by the Innovative Medicines Initiative Joint Undertaking (https://www.imi.europa.eu/) under Grant Agreement No. 115620 (COMBACTE-CARE).

Contact isolation versus standard precautions to decrease acquisition of extended-spectrum ß-lactamase-producing Enterobacterales in non-critical care wards: a cluster-randomised crossover trial.

BACKGROUND: The effectiveness of contact isolation for decreasing the spread of extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) has been questioned. The aim of this study was to establish the benefits of contact isolation over standard precautions for reducing the incidence density of ESBL-E colonisation and infection in adult medical and surgical wards with an active surveillance culture programme. METHODS: We did a cluster-randomised crossover trial in adult wards in four European university hospitals. Medical, surgical, or combined medical-surgical wards without critical care were randomised to continue standard precautions alone or implement contact isolation alongside standard precautions for 12 months, followed by a 1 month washout period and 12 months of the alternate strategy. Randomisation was done via a computer-generated sequence, with a block size of two consecutive wards. Only laboratory technicians and data analysts were masked to allocation. Patients were screened for ESBL-E carriage within 3 days of admission, once a week thereafter, and on discharge. The primary outcome was the incidence density of ESBL-E, defined as the acquisition rate per 1000 patient-days at risk at the ward level and assessed in the per-protocol population, which included all patients screened at least twice with a length of stay of more than 1 week for each intervention period. No specific safety measures were assessed given the minimal risk of adverse events. The trial is registered, ISRCTN57648070. FINDINGS: We enrolled 20 wards from four hospitals in Germany (eight wards), the Netherlands (four wards), Spain (four wards), and Switzerland (four wards). Between Jan 6, 2014, and Aug 31, 2016, 38 357 patients were admitted to these wards. Among 15 184 patients with a length of stay of more than 1 week, 11 368 patients (75%) were screened at least twice. The incidence density of ward-acquired ESBL-E was 6·0 events per 1000 patient-days at risk (95% CI 5·4-6·7) during periods of contact isolation and 6·1 (5·5-6·7) during periods of standard precautions (p=0·9710). Multivariable analysis adjusted for length of stay, percentage of patients screened, and prevalence in first screening cultures yielded an incidence rate ratio of 0·99 (95% CI 0·80-1·22; p=0·9177) for care under contact isolation compared with standard precautions. INTERPRETATION: Contact isolation showed no benefit when added to standard precautions for controlling the spread of ESBL-E on non-critical care wards with extensive surveillance screening. FUNDING: European Commission.