BNT162b2 Vaccine Effectiveness against Omicron in Children 5 to 11 Years of Age.

BACKGROUND: Limited evidence is available on the real-world effectiveness of the BNT162b2 vaccine against coronavirus disease 2019 (Covid-19) and specifically against infection with the omicron variant among children 5 to 11 years of age. METHODS: Using data from the largest health care organization in Israel, we identified a cohort of children 5 to 11 years of age who were vaccinated on or after November 23, 2021, and matched them with unvaccinated controls to estimate the vaccine effectiveness of BNT162b2 among newly vaccinated children during the omicron wave. Vaccine effectiveness against documented severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and symptomatic Covid-19 was estimated after the first and second vaccine doses. The cumulative incidence of each outcome in the two study groups through January 7, 2022, was estimated with the use of the Kaplan-Meier estimator, and vaccine effectiveness was calculated as 1 minus the risk ratio. Vaccine effectiveness was also estimated in age subgroups. RESULTS: Among 136,127 eligible children who had been vaccinated during the study period, 94,728 were matched with unvaccinated controls. The estimated vaccine effectiveness against documented infection was 17% (95% confidence interval [CI], 7 to 25) at 14 to 27 days after the first dose and 51% (95% CI, 39 to 61) at 7 to 21 days after the second dose. The absolute risk difference between the study groups at days 7 to 21 after the second dose was 1905 events per 100,000 persons (95% CI, 1294 to 2440) for documented infection and 599 events per 100,000 persons (95% CI, 296 to 897) for symptomatic Covid-19. The estimated vaccine effectiveness against symptomatic Covid-19 was 18% (95% CI, -2 to 34) at 14 to 27 days after the first dose and 48% (95% CI, 29 to 63) at 7 to 21 days after the second dose. We observed a trend toward higher vaccine effectiveness in the youngest age group (5 or 6 years of age) than in the oldest age group (10 or 11 years of age). CONCLUSIONS: Our findings suggest that as omicron was becoming the dominant variant, two doses of the BNT162b2 messenger RNA vaccine provided moderate protection against documented SARS-CoV-2 infection and symptomatic Covid-19 in children 5 to 11 years of age. (Funded by the European Union through the VERDI project and others.).

External Validity of a Randomized Controlled Trial on Duration of Antibiotics for the Treatment of Gram-Negative Bacteremia.

INTRODUCTION: Reports regarding the external validity of randomized controlled trials (RCTs) are scarce. We aimed to assess the population external validity of an investigator-initiated RCT on the duration of antibiotics for the treatment of Gram-negative bacteremia by comparing patients included in the RCT to patients that were not included in the trial. METHODS: Hospitalized patients with Gram-negative bacteremia were recruited into an RCT and randomized to receive 7 or 14 days of covering antibiotic therapy in Israel and Italy from 2013 to 2017. In a concomitant observational study, RCT participants were compared with patients who fulfilled the inclusion criteria but were not included in the trial due to participation in other trials, discharge before approached by researchers, refusal to participate, or unwillingness of the treating physician to allow participants' recruitment. RESULTS: Six hundred and four RCT patients were compared with 613 nonincluded patients. Almost 50% of nonincluded patients (288/613) were dependent on others for activities of daily living at baseline compared to 37.7% of RCT participants (228/604). Dementia was nearly 2-fold more frequent in nonincluded patients than those included (5.9% [36/613] versus 3.6% [22/604], p = 0.07). Patients who were not included in the RCT were more likely to acquire their infection in the hospital (53.3% [327/613] versus 29.1% [176/604], p < 0.001). The primary composite outcome of mortality, clinical failure, readmissions, or extended hospitalization at 90 days occurred in 353 of 613 nonincluded patients (57.6%) compared to 299 of 604 RCT participants (49.6%), p = 0.005. However, on multivariate analysis noninclusion in the RCT was not an independent risk factor for clinical failure and mortality. CONCLUSIONS: RCTs, even with broad eligibility criteria, do not represent the whole spectrum of patients and leave out a population with more severe illness for whom the evidence is lacking.

Assessment of Exercise Capacity of Individuals with Long COVID: A Cross-sectional Study.

BACKGROUND: Clinical investigations of long-term effects of coronavirus disease 2019 (COVID-19) are rarely translated to objective findings. OBJECTIVES: To assess the functional capacity of individuals reported on deconditioning that hampered their return to their pre-COVID routine. METHODS: Assessment included the 6-minute walk test (6MWT) and the 30-second sit-to-stand test (30-STST). We compared the expected and observed scores using the Wilcoxon signed-rank test. Predictors of test scores were identified using linear regression models. RESULTS: We included 49 individuals, of whom 38 (77.6%) were recovering from mild COVID-19. Twenty-seven (55.1%) individuals had a 6MWT score lower than 80% of expected. The average 6MWT scores were 129.5 ± 121.2 meters and 12.2 ± 5.0 repeats lower than expected scores, respectively (P < 0.001 for both). The 6MWT score was 107.3 meters lower for individuals with severe COVID-19 (P = 0.013) and rose by 2.7 meters per each 1% increase in the diffusing capacity of carbon monoxide (P = 0.007). The 30-STST score was 3.0 repeats lower for individuals who reported moderate to severe myalgia (P = 0.038). CONCLUSIONS: Individuals with long COVID who report on deconditioning exhibit significantly decreased physical capacity, even following mild acute illness. Risk factors include severe COVID-19 and impaired diffusing capacity or myalgia during recovery.

Risk Factors and Multidimensional Assessment of Long Coronavirus Disease Fatigue: A Nested Case-Control Study.

BACKGROUND: Fatigue is the most prevalent and debilitating long-COVID (coronavirus disease) symptom; however, risk factors and pathophysiology of this condition remain unknown. We assessed risk factors for long-COVID fatigue and explored its possible pathophysiology. METHODS: This was a nested case-control study in a COVID recovery clinic. Individuals with (cases) and without (controls) significant fatigue were included. We performed a multidimensional assessment evaluating various parameters, including pulmonary function tests and cardiopulmonary exercise testing, and implemented multivariable logistic regression to assess risk factors for significant long-COVID fatigue. RESULTS: A total of 141 individuals were included. The mean age was 47 (SD: 13) years; 115 (82%) were recovering from mild coronavirus disease 2019 (COVID-19). Mean time for evaluation was 8 months following COVID-19. Sixty-six (47%) individuals were classified with significant long-COVID fatigue. They had a significantly higher number of children, lower proportion of hypothyroidism, higher proportion of sore throat during acute illness, higher proportions of long-COVID symptoms, and of physical limitation in daily activities. Individuals with long-COVID fatigue also had poorer sleep quality and higher degree of depression. They had significantly lower heart rate [153.52 (22.64) vs 163.52 (18.53); P = .038] and oxygen consumption per kilogram [27.69 (7.52) vs 30.71 (7.52); P = .036] at peak exercise. The 2 independent risk factors for fatigue identified in multivariable analysis were peak exercise heart rate (OR: .79 per 10 beats/minute; 95% CI: .65-.96; P = .019) and long-COVID memory impairment (OR: 3.76; 95% CI: 1.57-9.01; P = .003). CONCLUSIONS: Long-COVID fatigue may be related to autonomic dysfunction, impaired cognition, and decreased mood. This may suggest a limbic-vagal pathophysiology. CLINICAL TRIALS REGISTRATION: NCT04851561.

Large-scale WGS of carbapenem-resistant Acinetobacter baumannii isolates reveals patterns of dissemination of ST clades associated with antibiotic resistance.

OBJECTIVES: To describe the population genetics and antibiotic resistance gene distribution of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates causing infections in three Mediterranean countries. METHODS: Isolates were collected during the 2013-17 AIDA clinical trial in six hospitals in Israel, Greece and Italy. WGS, bioinformatic characterization and antibiotic resistance profiling were performed. RESULTS: In the 247 CRAB isolates characterized in this study, ST distribution varied by country: 29/31 (93.5%) Greek isolates, 34/41 (82.9%) Italian isolates and 70/175 (40.0%) Israeli isolates belonged to ST2. The identified ST2 isolates included eight distinct clades: 2C, 2D and 2H were significantly more common in Italy, while 2F was unique to Greece. The uncommon ST3 was not present among Greek isolates and constituted only 5/41 (12%) Italian isolates. On the other hand, it was much more common among Israeli isolates: 78/175 (44.6%) belonged to ST3. The vast majority of isolates, 240/247 (97.2%), were found to harbour acquired carbapenemases, primarily blaOXA-23. The chromosomal oxaAb (blaOXA-51-like) and ampC genes characteristic of this organism were also ubiquitous. Most (96.4%) ST3 isolates carried a broad-host-range plasmid IncP1α. CONCLUSIONS: The geographical differences in CRAB populations support the theory that clonal spread of CRAB leads to endemicity in hospitals and regions. The close association between antibiotic resistance genes and clades, and between plasmids and STs, suggest that de novo creation of MDR A. baumannii is rare. The clustering of antibiotic resistance genes and plasmids that is unique to each clade/ST, and nearly uniform within clades/STs, suggests that horizontal transmission is rare but crucial to the clade's/ST's success.

Relevance of intra-hospital patient movements for the spread of healthcare-associated infections within hospitals - a mathematical modeling study.

The aim of this study is to analyze patient movement patterns between hospital departments to derive the underlying intra-hospital movement network, and to assess if movement patterns differ between patients at high or low risk of colonization. For that purpose, we analyzed patient electronic medical record data from five hospitals to extract information on risk stratification and patient intra-hospital movements. Movement patterns were visualized as networks, and network centrality measures were calculated. Next, using an agent-based model where agents represent patients and intra-hospital patient movements were explicitly modeled, we simulated the spread of multidrug resistant enterobacteriacae (MDR-E) inside a hospital. Risk stratification of patients according to certain ICD-10 codes revealed that length of stay, patient age, and mean number of movements per admission were higher in the high-risk groups. Movement networks in all hospitals displayed a high variability among departments concerning their network centrality and connectedness with a few highly connected departments and many weakly connected peripheral departments. Simulating the spread of a pathogen in one hospital network showed positive correlation between department prevalence and network centrality measures. This study highlights the importance of intra-hospital patient movements and their possible impact on pathogen spread. Targeting interventions to departments of higher (weighted) degree may help to control the spread of MDR-E. Moreover, when the colonization status of patients coming from different departments is unknown, a ranking system based on department centralities may be used to design more effective interventions that mitigate pathogen spread.

New ß-Lactam-ß-Lactamase Inhibitor Combinations.

The limited armamentarium against drug-resistant Gram-negative bacilli has led to the development of several novel ß-lactam-ß-lactamase inhibitor combinations (BLBLIs). In this review, we summarize their spectrum of in vitro activities, mechanisms of resistance, and pharmacokinetic-pharmacodynamic (PK-PD) characteristics. A summary of available clinical data is provided per drug. Four approved BLBLIs are discussed in detail. All are options for treating multidrug-resistant (MDR) Enterobacterales and Pseudomonas aeruginosa Ceftazidime-avibactam is a potential drug for treating Enterobacterales producing extended-spectrum ß-lactamase (ESBL), Klebsiella pneumoniae carbapenemase (KPC), AmpC, and some class D ß-lactamases (OXA-48) in addition to carbapenem-resistant Pseudomonas aeruginosa Ceftolozane-tazobactam is a treatment option mainly for carbapenem-resistant P. aeruginosa (non-carbapenemase producing), with some activity against ESBL-producing Enterobacterales Meropenem-vaborbactam has emerged as treatment option for Enterobacterales producing ESBL, KPC, or AmpC, with similar activity as meropenem against P. aeruginosa Imipenem-relebactam has documented activity against Enterobacterales producing ESBL, KPC, and AmpC, with the combination having some additional activity against P. aeruginosa relative to imipenem. None of these drugs present in vitro activity against Enterobacterales or P. aeruginosa producing metallo-ß-lactamase (MBL) or against carbapenemase-producing Acinetobacter baumannii Clinical data regarding the use of these drugs to treat MDR bacteria are limited and rely mostly on nonrandomized studies. An overview on eight BLBLIs in development is also provided. These drugs provide various levels of in vitro coverage of carbapenem-resistant Enterobacterales, with several drugs presenting in vitro activity against MBLs (cefepime-zidebactam, aztreonam-avibactam, meropenem-nacubactam, and cefepime-taniborbactam). Among these drugs, some also present in vitro activity against carbapenem-resistant P. aeruginosa (cefepime-zidebactam and cefepime-taniborbactam) and A. baumannii (cefepime-zidebactam and sulbactam-durlobactam).

Investigator-initiated Randomized Controlled Trials in Infectious Diseases: Better Value for Money for Registration Trials of New Antimicrobials.

Randomized controlled trials (RCTs) conducted by the industry are expensive, especially trials conducted for registration of new drugs for multidrug-resistant (MDR) bacteria. Lower-cost investigator-initiated trials have recently been successful in recruiting patients with severe infections caused by MDR bacteria. In this viewpoint, we contrast the aims, methods, and resulting costs of industry-led and investigator-initiated trials and ask whether contemporary registration trial costs are justified. Contract research organizations, delivering and monitoring industry-sponsored trials at a significant cost, have little incentive to make trials more efficient or less expensive. The value of universal monitoring of all trial data is questionable. We propose that clinical trial networks play a more influential role in RCT design and planning, lead adaptive risk-based trial monitoring, and work with the industry to maximize efficient recruitment and lower costs in registration trials for the approval of new antimicrobials.

ß-Blockers, Tachycardia, and Survival Following Sepsis: An Observational Cohort Study.

BACKGROUND: Sepsis is associated with excessive release of catecholamines, which causes tachycardia and is correlated with poor clinical outcome. ß-Blockers (BBs) may blunt this effect on heart rate (HR). The objective of this study is to assess whether long-term BB therapy is associated with better clinical outcomes in patients with sepsis admitted to internal medicine wards. METHODS: We performed a single-center, observational cohort study. We included adult patients who were hospitalized in medicine departments due to sepsis. A propensity score model for BB therapy was used to match patients. The primary outcome was the 30-day all-cause mortality rate. A multivariate analysis was performed to identify risk factors for an adverse outcome. Patients were stratified according to absolute tachycardia (HR ≥100/min) or relative tachycardia at presentation (tachycardia index above the third quartile, with tachycardia index defined as the ratio of HR to temperature). RESULTS: A total of 1186 patients fulfilled the inclusion criteria. In the propensity-matched cohort patients given BB treatment were younger (median age [interquartile range], 74 [62-82] vs 81 [68-87] years; P ≤ .001). BB treatment was associated with reduction in 30-day mortality rates for patients with absolute tachycardia (odds ratio, 0.406; 95% confidence interval, .177-.932). Final model with interaction variable of BB treatment with HR was associated with short-term survival (odds ratio, 0.38; 95% confidence interval, .148-.976). Selective BB therapy had a stronger protective effect than nonselective BB therapy. CONCLUSIONS: Long-term BB therapy was associated with decreased mortality rate in patients hospitalized with sepsis in internal medicine wards exhibiting absolute and relative tachycardia.

Combination versus monotherapy as definitive treatment for Pseudomonas aeruginosa bacteraemia: a multicentre retrospective observational cohort study.

BACKGROUND: Pseudomonas aeruginosa bacteraemia is a common and serious infection. No consensus exists regarding whether definitive combination therapy is superior to monotherapy. We aimed to evaluate the impact of combination therapy on mortality. METHODS: This was a multicentre retrospective study (nine countries, 25 centres), including 1277 patients with P. aeruginosa bacteraemia during 2009-15. We evaluated the association between ß-lactam plus aminoglycoside or quinolone combination therapy versus ß-lactam monotherapy and mortality. The primary outcome was 30 day all-cause mortality. Univariate and multivariate Cox regression analyses were conducted, introducing combination as a time-dependent variable. Propensity score was conducted to adjust for confounding for choosing combination therapy over monotherapy. RESULTS: Of 1119 patients included, 843 received definitive monotherapy and 276 received combination therapy (59% aminoglycoside and 41% quinolone). Mortality at 30 days was 16.9% (189/1119) and was similar between combination (45/276; 16.3%) and monotherapy (144/843; 17.1%) groups (P = 0.765). In multivariate Cox regression, combination therapy was not associated with reduced mortality (HR 0.98, 95% CI 0.64-1.53). No advantage in terms of clinical failure, microbiological failure or recurrent/persistent bacteraemia was demonstrated using combination therapy. Likewise, adverse events and resistance development were similar for the two regimens. CONCLUSIONS: In this retrospective cohort, no mortality advantage was demonstrated using combination therapy over monotherapy for P. aeruginosa bacteraemia. Combination therapy did not improve clinical or microbiological failure rates, nor affect adverse events or resistance development. Our finding of no benefit with combination therapy needs confirmation in well-designed randomized controlled trials.

Risk factors for enterococcal urinary tract infections: a multinational, retrospective cohort study.

Complicated urinary tract infection (cUTI) is a frequent cause of morbidity. In this multinational retrospective cohort study, we aimed to demonstrate risk factors for enterococcal UTI. Univariate and multivariate analyses of risk factors for enterococcal infection were performed. Among 791 hospitalized patients with cUTI, enterococci accounted for approximately 10% of cases (78/791). Risk factors for enterococcal UTI in multivariable analysis were male gender, age range of 55-75 years, catheter-associated UTI, and urinary retention. This information may assist treating physicians in their decision-making on prescribing empiric anti-enterococcus treatment to hospitalized patients presenting with cUTI and thus improve clinical outcomes.

Excluded versus included patients in a randomized controlled trial of infections caused by carbapenem-resistant Gram-negative bacteria: relevance to external validity.

BACKGROUND: Population external validity is the extent to which an experimental study results can be generalized from a specific sample to a defined population. In order to apply the results of a study, we should be able to assess its population external validity. We performed an investigator-initiated randomized controlled trial (RCT) (AIDA study), which compared colistin-meropenem combination therapy to colistin monotherapy in the treatment of patients infected with carbapenem-resistant Gram-negative bacteria. In order to examine the study's population external validity and to substantiate the use of AIDA study results in clinical practice, we performed a concomitant observational trial. METHODS: The study was conducted between October 1st, 2013 and January 31st, 2017 (during the RCTs recruitment period) in Greece, Israel and Italy. Patients included in the observational arm of the study have fulfilled clinical and microbiological inclusion criteria but were excluded from the RCT due to receipt of colistin for > 96 h, refusal to participate, or prior inclusion in the RCT. Non-randomized cases were compared to randomized patients. The primary outcome was clinical failure at 14 days of infection onset. RESULTS: Analysis included 701 patients. Patients were infected mainly with Acinetobacter baumannii [78.2% (548/701)]. The most common reason for exclusion was refusal to participate [62% (183/295)]. Non-randomized and randomized patients were similar in most of the demographic and background parameters, though randomized patients showed minor differences towards a more severe infection. Combination therapy was less common in non-randomized patients [31.9% (53/166) vs. 51.2% (208/406), p = 0.000]. Randomized patients received longer treatment of colistin [13 days (IQR 10-16) vs. 8.5 days (IQR 0-15), p = 0.000]. Univariate analysis showed that non-randomized patients were more inclined to clinical failure on day 14 from infection onset [82% (242/295) vs. 75.5% (307/406), p = 0.042]. After adjusting for other variables, non-inclusion was not an independent risk factor for clinical failure at day 14. CONCLUSION: The similarity between the observational arm and RCT patients has strengthened our confidence in the population external validity of the AIDA trial. Adding an observational arm to intervention studies can help increase the population external validity and improve implementation of study results in clinical practice. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov, number NCT01732250 on November 22, 2012.

The Effect of ß-Blockers for Burn Patients on Clinical Outcomes: Systematic Review and Meta-Analysis.

OBJECTIVES: To assess the effects and safety of ß-blockers in hospitalized patients with burns. METHODS: A systematic review and meta-analysis of the literature. A broad search was conducted to identify all randomized controlled trials (RCTs) comparing ß-blockers to control in hospitalized patients with burns. The primary outcome was 3-month all-cause mortality. Secondary outcomes were clinical patient-relevant end points. We subgrouped results by children/adults and burn severity. Risk of bias was assessed using the individual domain approach. RESULTS: Four RCTs reported in 11 publications were included. Primary outcome of mortality was assessed in children (2 trials, n = 424) and adults (2 trials, n = 148) with severe burns. No significant difference was found between propranolol and control for mortality (risk ratio [RR] = 0.82, 95% CI = 0.48-1.39, 4 trials with broad confidence intervals in adults and children), sepsis (RR = 0.81, 95% CI = 0.46-1.43, 2 trials), and survivors' length of stay (absolute mean difference = 2.53, 95% CI = -2.58-7.63, 3 trials). There was no significant difference in bradycardia (RR = 1.33, 95% CI = 0.77-2.3, 2 trials), hypotension (RR = 1.26, 95% CI = 0.73-2.17, 3 trials), or cardiac arrhythmia (RR: 2.97, 95% CI: 0.12-71.87, 1 trial). The evidence was graded as very low certainty, due to trial's internal risk of bias, imprecision, and possible selective reporting. CONCLUSIONS: No sufficient evidence was found to support or refute an advantage for ß-blocker use in children or adults after burns. Additional studies are needed to create a consensus and formulate practice guidelines on the optimal ß-blocker to use, indications for initiation, and duration of treatment.

Colistin Resistance Development Following Colistin-Meropenem Combination Therapy Versus Colistin Monotherapy in Patients With Infections Caused by Carbapenem-Resistant Organisms.

BACKGROUND: We evaluated whether carbapenem-colistin combination therapy reduces the emergence of colistin resistance, compared to colistin monotherapy, when given to patients with infections due to carbapenem-resistant Gram-negative organisms. METHODS: This is a pre-planned analysis of a secondary outcome from a randomized, controlled trial comparing colistin monotherapy with colistin-meropenem combination for the treatment of severe infections caused by carbapenem-resistant, colistin-susceptible Gram-negative bacteria. We evaluated rectal swabs taken on Day 7 or later for the presence of new colistin-resistant (ColR) isolates. We evaluated the emergence of any ColR isolate and the emergence of ColR Enterobacteriaceae (ColR-E). RESULTS: Data were available for 214 patients for the primary analysis; emergent ColR organisms were detected in 22 (10.3%). No difference was observed between patients randomized to treatment with colistin monotherapy (10/106, 9.4%) versus patients randomized to colistin-meropenem combination therapy (12/108, 11.1%; P = .669). ColR-E organisms were detected in 18/249 (7.2%) patients available for analysis. No difference was observed between the 2 treatment arms (colistin monotherapy 6/128 [4.7%] vs combination therapy 12/121 [9.9%]; P = .111). Enterobacteriaceae, as the index isolate, was found to be associated with development of ColR-E (hazard ratio, 3.875; 95% confidence interval, 1.475-10.184; P = .006). CONCLUSIONS: Carbapenem-colistin combination therapy did not reduce the incidence of colistin resistance emergence in patients with infections due to carbapenem-resistant organisms. Further studies are necessary to elucidate the development of colistin resistance and methods for its prevention.

Ceftazidime, Carbapenems, or Piperacillin-tazobactam as Single Definitive Therapy for Pseudomonas aeruginosa Bloodstream Infection: A Multisite Retrospective Study.

BACKGROUND: The optimal antibiotic regimen for Pseudomonas aeruginosa bacteremia is controversial. Although ß-lactam monotherapy is common, data to guide the choice between antibiotics are scarce. We aimed to compare ceftazidime, carbapenems, and piperacillin-tazobactam as definitive monotherapy. METHODS: A multinational retrospective study (9 countries, 25 centers) including 767 hospitalized patients with P. aeruginosa bacteremia treated with ß-lactam monotherapy during 2009-2015. The primary outcome was 30-day all-cause mortality. Univariate and multivariate, including propensity-adjusted, analyses were conducted introducing monotherapy type as an independent variable. RESULTS: Thirty-day mortality was 37/213 (17.4%), 42/210 (20%), and 55/344 (16%) in the ceftazidime, carbapenem, and piperacillin-tazobactam groups, respectively. Type of monotherapy was not significantly associated with mortality in either univariate, multivariate, or propensity-adjusted analyses (odds ratio [OR], 1.14; 95% confidence interval [CI], 0.52-2.46, for ceftazidime; OR, 1.3; 95% CI, 0.67-2.51, for piperacillin-tazobactam, with carbapenems as reference in propensity adjusted multivariate analysis; 542 patients). No significant difference between antibiotics was demonstrated for clinical failure, microbiological failure, or adverse events. Isolation of P. aeruginosa with new resistance to antipseudomonal drugs was significantly more frequent with carbapenems (36/206 [17.5%]) versus ceftazidime (25/201 [12.4%]) and piperacillin-tazobactam (28/332 [8.4%] (P = .007). CONCLUSIONS: No significant difference in mortality, clinical, and microbiological outcomes or adverse events was demonstrated between ceftazidime, carbapenems, and piperacillin-tazobactam as definitive treatment of P. aeruginosa bacteremia. Higher rates of resistant P. aeruginosa after patients were treated with carbapenems, along with the general preference for carbapenem-sparing regimens, suggests using ceftazidime or piperacillin-tazobactam for treating susceptible infection.

White Paper: Bridging the gap between human and animal surveillance data, antibiotic policy and stewardship in the hospital sector-practical guidance from the JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks.

BACKGROUND: Antimicrobial surveillance and antimicrobial stewardship (AMS) are essential pillars in the fight against antimicrobial resistance (AMR), but practical guidance on how surveillance data should be linked to AMS activities is lacking. This issue is particularly complex in the hospital setting due to structural heterogeneity of hospital facilities and services. The JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks have joined efforts to formulate a set of target actions for linking surveillance data with AMS activities. METHODS: A scoping review of the literature was carried out addressing research questions on three areas: (i) AMS leadership and accountability; (ii) antimicrobial usage and AMS; (iii) AMR and AMS. Consensus on the target actions was reached through a RAND-modified Delphi process involving over 40 experts in different fields from 18 countries. RESULTS: Evidence was retrieved from 51 documents. Initially 38 targets were proposed, differentiated as essential or desirable according to clinical relevance, feasibility and applicability to settings and resources. In the first consultation round, preliminary agreement was reached for 32 targets. Following a second consultation, 27 targets were approved, 11 were deleted and 4 were suggested for rephrasing, leading to a final approved list of 34 target actions in the form of a practical checklist. CONCLUSIONS: This White Paper provides a pragmatic and flexible tool to guide the development of calibrated hospital-surveillance-based AMS interventions. The strength of this tool is that it is a comprehensive perspective that takes into account the hospital patient case-mix and the related epidemiology, which ultimately drives antimicrobial usage, and the feasibility in low-resource settings.

Risk Factors for Treatment Failure and Mortality Among Hospitalized Patients With Complicated Urinary Tract Infection: A Multicenter Retrospective Cohort Study (RESCUING Study Group).

Background: Complicated urinary tract infections (cUTIs) are responsible for a major share of all antibiotic consumption in hospitals. We aim to describe risk factors for treatment failure and mortality among patients with cUTIs. Methods: A multinational, multicentre retrospective cohort study, conducted in 20 countries in Europe and the Middle East. Data were collected from patients' files on hospitalised patients with a diagnosis of cUTI during 2013-2014. Primary outcome was treatment failure, secondary outcomes included 30 days all-cause mortality,among other outcomes. Multivariable analysis using a logistic model and the hospital as a random variable was performed to identify independent predictors for these outcomes. Results: A total of 981 patients with cUTI were included. Treatment failure was observed in 26.6% (261/981), all cause 30-day mortality rate was 8.7% (85/976), most of these in patients with catheter related UTI (CaUTI). Risk factors for treatment failure in multivariable analysis were ICU admission (OR 5.07, 95% CI 3.18-8.07), septic shock (OR 1.92, 95% CI 0.93-3.98), corticosteroid treatment (OR 1.92, 95% CI 1.12-3.54), bedridden (OR 2.11, 95%CI 1.4-3.18), older age (OR 1.02, 95% CI 1.0071.03-), metastatic cancer (OR 2.89, 95% CI 1.46-5.73) and CaUTI (OR 1.48, 95% CI 1.04-2.11). Management variables, such as inappropriate empirical antibiotic treatment or days to starting antibiotics were not associated with treatment failure or 30-day mortality. More patients with pyelonephritis were given appropriate empirical antibiotic therapy than other CaUTI [110/171; 64.3% vs. 116/270; 43%, p <0.005], nevertheless, this afforded no advantage in treatment failure rates nor mortality in these patients. Conclusions: In patients with cUTI we found no benefit of early appropriate empirical treatment on survival rates or other outcomes. Physicians might consider supportive treatment and watchful waiting in stable patients until the causative pathogen is defined.

Good Studies Evaluate the Disease While Great Studies Evaluate the Patient: Development and Application of a Desirability of Outcome Ranking Endpoint for Staphylococcus aureus Bloodstream Infection.

BACKGROUND: Desirability of outcome ranking (DOOR) is an innovative approach in clinical trials to evaluate the global benefits and risks of an intervention. We developed and validated a DOOR endpoint for Staphylococcus aureus bloodstream infection (BSI) through a survey to infectious diseases clinicians and secondary analysis of trial data. METHODS: We administered a survey of 20 cases of S. aureus BSI, asking respondents to rank outcomes by global desirability. Correlations and percentage of pairwise agreement among rankings were estimated to inform development of a DOOR endpoint, which was applied to 2 prior S. aureus BSI trials. The probability that a patient randomly assigned to experimental treatment would have a better DOOR ranking than if assigned to control was estimated. Results were also analyzed using partial credit, which is analogous to scoring an academic test, assigning 100% to the most desirable outcome, 0% to the least, and "partial credit" to intermediate ranks. RESULTS: Forty-two recipients (97%) completed the survey. The DOOR endpoint fitting these rankings (r = 0.89; 95% confidence interval, 0.67 to 0.94) incorporated survival plus cumulative occurrence of adverse events, cure, infectious complications, and ongoing symptoms. Tailored versions of this endpoint were applied to 2 S. aureus BSI trials, and both demonstrated no benefit of the experimental treatment using DOOR and partial credit analysis. CONCLUSIONS: Using S. aureus BSI as an exemplar, we developed a DOOR endpoint that can be used as a template for development of DOOR endpoints for other diseases. Future trials can incorporate DOOR to allow for global assessment of patient experience.

Treatment Outcomes of Colistin- and Carbapenem-resistant Acinetobacter baumannii Infections: An Exploratory Subgroup Analysis of a Randomized Clinical Trial.

BACKGROUND: We evaluated the association between mortality and colistin resistance in Acinetobacter baumannii infections and the interaction with antibiotic therapy. METHODS: This is a secondary analysis of a randomized controlled trial of patients with carbapenem-resistant gram-negative bacterial infections treated with colistin or colistin-meropenem combination. We evaluated patients with infection caused by carbapenem-resistant A. baumannii (CRAB) identified as colistin susceptible (CoS) at the time of treatment and compared patients in which the isolate was confirmed as CoS with those whose isolates were retrospectively identified as colistin resistant (CoR) when tested by broth microdilution (BMD). The primary outcome was 28-day mortality. RESULTS: Data were available for 266 patients (214 CoS and 52 CoR isolates). Patients with CoR isolates had higher baseline functional capacity and lower rates of mechanical ventilation than patients with CoS isolates. All-cause 28-day mortality was 42.3% (22/52) among patients with CoR strains and 52.8% (113/214) among patients with CoS isolates (P = .174). After adjusting for variables associated with mortality, the mortality rate was lower among patients with CoR isolates (odds ratio [OR], 0.285 [95% confidence interval {CI}, .118-.686]). This difference was associated with treatment arm: Mortality rates among patients with CoR isolates were higher in those randomized to colistin-meropenem combination therapy compared to colistin monotherapy (OR, 3.065 [95% CI, 1.021-9.202]). CONCLUSIONS: Colistin resistance determined by BMD was associated with lower mortality among patients with severe CRAB infections. Among patients with CoR isolates, colistin monotherapy was associated with a better outcome compared to colistin-meropenem combination therapy. CLINICAL TRIALS REGISTRATION: NCT01732250.

Seven Versus 14 Days of Antibiotic Therapy for Uncomplicated Gram-negative Bacteremia: A Noninferiority Randomized Controlled Trial.

BACKGROUND: Gram-negative bacteremia is a major cause of morbidity and mortality in hospitalized patients. Data to guide the duration of antibiotic therapy are limited. METHODS: This was a randomized, multicenter, open-label, noninferiority trial. Inpatients with gram-negative bacteremia, who were afebrile and hemodynamically stable for at least 48 hours, were randomized to receive 7 days (intervention) or 14 days (control) of covering antibiotic therapy. Patients with uncontrolled focus of infection were excluded. The primary outcome at 90 days was a composite of all-cause mortality; relapse, suppurative, or distant complications; and readmission or extended hospitalization (>14 days). The noninferiority margin was set at 10%. RESULTS: We included 604 patients (306 intervention, 298 control) between January 2013 and August 2017 in 3 centers in Israel and Italy. The source of the infection was urinary in 411 of 604 patients (68%); causative pathogens were mainly Enterobacteriaceae (543/604 [90%]). A 7-day difference in the median duration of covering antibiotics was achieved. The primary outcome occurred in 140 of 306 patients (45.8%) in the 7-day group vs 144 of 298 (48.3%) in the 14-day group (risk difference, -2.6% [95% confidence interval, -10.5% to 5.3%]). No significant differences were observed in all other outcomes and adverse events, except for a shorter time to return to baseline functional status in the short-course therapy arm. CONCLUSIONS: In patients hospitalized with gram-negative bacteremia achieving clinical stability before day 7, an antibiotic course of 7 days was noninferior to 14 days. Reducing antibiotic treatment for uncomplicated gram-negative bacteremia to 7 days is an important antibiotic stewardship intervention. CLINICAL TRIALS REGISTRATION: NCT01737320.