Clinical epidemiology of carbapenem-resistant gram-negative sepsis among hospitalized patients: Shifting burden of disease?

Clinical outcomes of carbapenem-resistant gram-negative bacterial bloodstream infection in patients with end-stage renal disease in intensive care units: a multicenter retrospective observational study

BACKGROUND

Carbapenem-resistant gram-negative bacteria (CRGNB) present a considerable global threat due to their challenging treatment and increased mortality rates, with bloodstream infection (BSI) having the highest mortality rate. Patients with end-stage renal disease (ESRD) undergoing renal replacement therapy (RRT) face an increased risk of BSI. Limited data are available regarding the prognosis and treatment outcomes of CRGNB-BSI in patients with ESRD in intensive care units (ICUs).

METHODS

This multi-center retrospective observational study included a total of 149 ICU patients with ESRD and CRGNB-BSI in Taiwan from January 2015 to December 2019. Clinical and microbiological outcomes were assessed, and multivariable regression analysis was used to evaluate the independent risk factors for day-28 mortality and the impact of antimicrobial therapy regimen on treatment outcomes.

RESULTS

Among the 149 patients, a total of 127 patients (85.2%) acquired BSI in the ICU, with catheter-related infections (47.7%) and pneumonia (32.2%) being the most common etiologies. Acinetobacter baumannii (49.0%) and Klebsiella pneumoniae (31.5%) were the most frequently isolated pathogens. The day-28 mortality rate from BSI onset was 52.3%, and in-hospital mortality was 73.2%, with survivors experiencing prolonged hospital stays. A higher Sequential Organ Failure Assessment (SOFA) score (adjusted hazards ratio [aHR], 1.25; 95% confidence interval [CI] 1.17-1.35) and shock status (aHR, 2.12; 95% CI 1.14-3.94) independently predicted day-28 mortality. Colistin-based therapy reduced day-28 mortality in patients with shock, a SOFA score of ≥ 13, and Acinetobacter baumannii-related BSI.

CONCLUSIONS

CRGNB-BSI led to high mortality in critically ill patients with ESRD. Day-28 mortality was independently predicted by a higher SOFA score and shock status. In patients with higher disease severity and Acinetobacter baumannii-related BSI, colistin-based therapy improved treatment outcomes.

Carbapenemase producing Enterobacterales at a large teaching hospital in Ohio: comparison to state surveillance and retrospective analysis of patient characteristics

Background

The presence of carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) around the world is increasing, particularly in healthcare settings. Surveillance testing for plasmid-mediated carbapenemase genes is necessary to tracking CP-CRE infections.

Aim

In the state of Ohio, surveillance of carbapenem-resistant Enterobacterales (CRE) began in 2018, and to the authors' knowledge data on these cases has not been published to date. This study analyzed data on CRE from a large teaching hospital in Ohio, and by the Ohio Department of Health Laboratory (ODHL).

Methods

Carbapenemase production was detected using mCIM, and plasmid-mediated carbapenemase genes were detected using rtPCR. Data was collected on 344 standard-of-care isolates from a large teaching hospital in Ohio, including data collected from chart review. Deidentified surveillance data on 4,391 CRE isolates was provided by the ODHL. Statistical analysis was performed using binary logistic regression.

Findings

While KPC was the most common carbapenemase gene (n=1590), NDM (n=98), VIM (n=10), IMP (n=39) and OXA-48 (n=35) were also detected in the isolates studied. Klebsiella pneumoniae and Enterobacter cloacae were the most common CRE, and carbapenemase genes were most commonly detected in K. pneumoniae. Inpatient hospital stays and long-term care were associated with CP-CRE and were more common in women.

Conclusion

Surveillance data shows that CP-CRE are present in Ohio, most commonly in Klebsiella pneumoniae. A better understanding of the prevalence of CRE, plasmid-mediated carbapenemase genes present, and the populations affected are important when tracking the spread of disease. Further study and surveillance of carbapenem-resistant organisms can provide a better understanding of their prevalence in the state.

Use of hospital resources in ICU inpatients with infections caused by carbapenem-resistant Gram-negative bacteria: A real clinical practice-based study in Spain

INTRODUCTION

Carbapenem-resistant Gram-negative bacteria (CRGN) are an urgent public health threat because of the limited treatment options, its rapid spreading and high clinical impact and mortality rates. However, the burden and the use of resources of these infections have not been investigated. The aim of the current study is to understand the use of resources associated to the clinical management of CRGN infections in real clinical practice conditions.

METHODS

An observational retrospective chart review study was performed. Data regarding patient demographics, clinical management and use of resources associated to hospitalization were retrieved from clinical charts of ICU inpatients with a confirmed CRGN infection. Three reference Spanish hospitals were selected according to their patient volume and geographical coverage. Descriptive analyses of the clinical management and the use of resources and its cost were performed and then total costs by type of resource were calculated.

RESULTS

A total of 130 patients were included in the study. The higher number of patients (n=43; 33%) were between 61 and 70 years old. Ninety-four (72%) patients were male and 115 (88%) suffered from comorbidities. The mean total cost associated to the resources used in patients with CRGN infections hospitalized in ICU was 96,878€ per patient. These total costs included 84,140€ of total hospital stay, 11,021€ of treatments (558€ of antibiotics; 10,463€ of other treatments) and 1717€ costs of diagnostic tests.

CONCLUSIONS

CRGN infection causes a high use of hospital resources, being the length of stay either in hospital wards or ICU the driver of the total costs. Diagnostic tests and treatments, including antibiotics, represent the lowest part of the use of resources and costs (13% of total costs).

Changing Epidemiology and Decreased Mortality Associated With Carbapenem-resistant Gram-negative Bacteria, 2000-2017

BACKGROUND

Carbapenem-resistant gram-negative bacteria (CRGNB) continue to present a global healthcare crisis. We aimed to identify emerging trends of CRGNB over nearly 2 decades and describe the impact of CRGNB on patient outcomes.

METHODS

Patients from whom CRGNB were isolated between 2000 and 2017 were included in the study. Carbapenem resistance was defined by the most recent breakpoints and applied across the study period. Patient demographics, clinical characteristics, and outcomes were retrieved from the electronic health record.

RESULTS

A total of 94 888 isolates from 64 422 patients were identified; 9882 (10%) isolates from 4038 patients were carbapenem-resistant. Pseudomonas aeruginosa was the most common CRGNB each year. The second most common CRGNB emerged in waves over time. Carbapenem daily defined doses increased in parallel with CRGNB rates (R2 = 0.8131). The overall 30-day mortality rate was 19%, which decreased from 24% in 2000 to 17% in 2017 (P = .003; R2 = .4330). Among patients with CRGNB bloodstream infections (n = 319), overall 30- and 90-day mortality rates were 27% and 38%, respectively. Charlson score (adjusted odds ratio [aOR], 1.11 per point), intensive care unit residence (aOR, 7.32), and severe liver disease (aOR, 4.8.4) were independent predictors of 30-day mortality, while receipt of transplantation was associated with lower rates of death (aOR, 0.39). Among patients admitted between 2011 and 2017 (n = 2230), 17% died during hospitalization, 32% were transferred to long-term care facilities, and 38% were discharged home.

CONCLUSIONS

CRGNB emerged in waves over time, causing high rates of mortality. Despite increasing rates of CRGNB, overall patient outcomes have improved, suggesting that recognition and novel therapeutics have made a major impact.

Clinical and Demographic Characteristics of Patients With a New Diagnosis of Carriage or Clinical Infection With Carbapenemase-Producing Enterobacterales: A Retrospective Study

Background: To examine the clinical, demographic, and microbiologic characteristics of new rectal carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) carriers vs. those with a clinical infection, hospitalized at Padeh-Poriya Medical Center between 2014 and 2017 and to examine the susceptibility profiles of isolates from clinical infections.

Methods: In this retrospective, chart analysis, demographic and clinical data were collected from medical charts of 175 adult patients with either new- onset carbapenemase-producing Enterobacterales (CPE) carriage or clinical CPE infection. Collected data included age, ethnic group, place of residence, hospitalizations in the past 90 days, and 30-day mortality. Microbiological analyses considered bacterial genus, molecular resistance mechanism and antibiotic susceptibility.

Results: A significantly higher percentage (42.4%) of CPE carriers were long-term care facility residents, and had been recently hospitalized (56.3%), as compared to patients with clinical CPE infection (29.2 and 45.9%, respectively). Additionally, we noted a high (58.3%) acquision of CPE in our hospital. The most common bacterial isolate was K. pneumoniae and the most common resistance mechanism was Klebsiella pneumoniae (K. pneumoniae) carbapenemases (KPC). High susceptibility rates to amikacin and chloramphenicol were also noted.

Conclusions: This study reaffirmed the importance of CPE screening and infection control measures. The observed antibiotic susceptibility profile suggests amikacin and chloramphenicol as potential treatments for CPE infection.

Predictors of Mortality in Patients with Carbapenem-Resistant Gram-Negative Bacilli or Vancomycin-Resistant Enterococci Bacteremia

Purpose

The incidences of carbapenem-resistant gram-negative bacilli (CRGNB) and vancomycin-resistant Enterococci (VRE) have increased rapidly in South Korea since 2000. The mortality rate for CRGNB or VRE bacteremia cases is higher than that for non-resistant bacteremia cases. The factors associated with higher mortality are unclear. We investigated the factors associated with mortality from CRGNB or VRE bacteremia and compared the relative risk of these factors.

Patients and Methods

We retrospectively collected data from adult patients with CRGNB or VRE bacteremia. Patients were grouped according to whether they survived or died. The data from both groups were compared.

Results

During the study period, 171 cases of CRGNB or VRE bacteremia were identified, of which 100 were CRGNB bacteremia cases and 71 were VRE bacteremia cases. Multivariate analysis revealed significant associations with Pitt bacteremia score (PBS) (odds ratio [OR] 1.329, 95% confidence interval [CI] 1.049-1.684). In the multivariate analysis, negative conversion of follow-up blood culture (FUBC) was related with one-week mortality from CRGNB or VRE bacteremia (OR 17.623, 95% CI 5.726-54.244). In the multivariate analysis of risk factors for 28-day mortality for CRGNB or VRE bacteremia, the significant risk factors were bacteremia of respiratory origin (OR 4.491, 95% CI 1.622-12.435) and positive FUBC (OR 4.082, 95% CI 1.626-10.204).

Conclusion

Despite the high mortality rate in patients with CRGNB or VRE bacteremia, the related mortality could be predicted by independent risk factors of PBS, positive FUBC, and bacteremia of respiratory origin.

Determining the burden of infectious diseases caused by carbapenem-resistant gram-negative bacteria in Spain

OBJECTIVE

To estimate the burden of nosocomial infections induced by carbapenem resistant Gram-negative (CRGN) pathogens in Spain, focusing on both the clinical and economic impact.

METHODS

The burden of disease was estimated using data from 2017 according to the availability of data sources. The impact, both clinical and economic, of the most frequent CRGN nosocomial infections (those produced by Klebsiella pneumoniae, Pseudomonasaeruginosa and Acinetobacter baumannii) was analysed. Incidence and mortality of CRGN nosocomial infections were estimated, as well as the direct and indirect costs produced by this health problem.

RESULTS

Approximately 376,346 patients are believed to have suffered a nosocomial infection in Spain in 2017; 3.2% of them due to CRGN bacilli. Infections by carbapenem-resistant P. aeruginosa produced the highest mortality rates (2578 deaths) when compared with A. baumannii (1571) and K. pneumoniae (415). Total economic costs of CRGN nosocomial infections in Spain were estimated to be €472 million in 2017, with 83% of the total cost caused by direct costs.

CONCLUSION

CRGN nosocomial infections have a high clinical impact on patients' lives, high mortality rates, and represent one of the hospitalisation episodes with the most associated costs. Efforts should be focussed to implement preventive policies in order to avoid infections due to CRGN pathogens and the resulting burden, and to reduce direct costs due to morbimortality, specifically in those infections produced by P. aeruginosa.

Evaluation of Eravacycline: A Novel Fluorocycline

Eravacycline (ERV), formerly known as TP-434, is a novel tetracycline (TET) antibiotic that exhibits in vitro activity against various gram-positive, gram-negative aerobic and anaerobic pathogens, including those exhibiting TET-specific acquired resistance mechanisms. Similar to other TETs, it inhibits protein synthesis through binding to the 30S ribosomal subunit. Eravacycline was approved by the United States Food and Drug Administration (FDA) in August 2018 for the treatment of complicated intraabdominal infections (cIAIs) in adults following the Investigating Gram-Negative Infections Treated with Eravacycline (IGNITE)1 and IGNITE4 phase III trials. In these two, double-blind, multicenter clinical trials, ERV was proven noninferior in terms of clinical response in comparison to ertapenem and meropenem, respectively. Eravacycline was well tolerated with nausea, vomiting, and infusion site reactions being the most commonly reported adverse reactions. Clinicians now have ERV as a novel therapeutic option for the treatment of adults with intraabdominal infections, allergies to β-lactam agents, Clostridioides difficile-associated diarrhea, or if tolerability to other agents is a concern.

Plazomicin: A Next-Generation Aminoglycoside

Plazomicin is a novel aminoglycoside antibiotic that binds to the bacterial 30S ribosomal subunit, thus inhibiting protein synthesis in a concentration-dependent manner. Plazomicin displays a broad spectrum of activity against aerobic gram-negative bacteria including extended-spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and organisms with aminoglycoside-modifying enzymes. In a large phase III clinical trial, plazomicin was shown to be noninferior to meropenem in the treatment of complicated urinary tract infections (cUTIs) with respect to the coprimary efficacy end points of the microbiologically modified intent-to-treat composite cure rate at day 5 (plazomicin 88% [168/191 subjects] vs meropenem 91.4% [180/197]) and at the test-of-cure visit (plazomicin 81.7% [156/191] vs meropenem 70.1% [138/197]). In a small phase III clinical trial, plazomicin was shown to be effective in the treatment of infections caused by carbapenem-resistant Enterobacteriaceae. It was associated with a lower all-cause mortality or significant disease-related complication rate (23.5% [4/17]) compared with colistin (50% [10/20]). The most common adverse reactions associated with plazomicin are decreased renal function, diarrhea, hypertension, headache, nausea, vomiting, and hypotension. As with other aminoglycosides, plazomicin may cause neuromuscular blockade, ototoxicity, and fetal harm in pregnant women. Due to limited efficacy and safety data, plazomicin is indicated for the treatment of cUTIs in adults with limited or no alternative treatment options, using a dosage regimen of 15 mg/kg intravenously every 24 hours for 4-7 days. Dosage reductions and therapeutic drug monitoring are warranted in patients with moderate or severe renal impairment. Plazomicin is not recommended in patients with severe renal impairment including those receiving renal replacement therapy. With the approval of plazomicin, clinicians now have an additional option for the treatment of adults with cUTIs, particularly those caused by multidrug-resistant gram-negative rods.