Bloodstream infections: trends and evolution of incidence and etiology in a 12-year period (2010-2021)

INTRODUCTION

The epidemiological evolution of bloodstream infections (BSIs) in the last decade is not clearly defined. Our aim was to analyze the changes in the workload in our institution and to describe the evolution of the incidence and etiology of BSIs in a 12-year period, including the COVID-19 pandemic.

METHODS

All blood cultures received in the laboratory of a tertiary general hospital between 2010 and 2021 were analyzed. Bloodstream infection episodes refer to each episode of bacteremia or fungemia in each patient. Incidence rates per 1000 admissions and per 100,000 population were calculated.

RESULTS

No significant changes in the incidence of BSI episodes/1000 admissions were observed (mean, 31.1), while estimated population-based incidences showed declining trends (mean, 182.8/100,000 inhabitants). There was a slight increase in BSI episodes per 1000 admissions caused by Gram-negatives (mean, 16.6/1000 admissions) and E. coli was the most frequent pathogen (mean, 8.5/1000 admissions). There was no significant rise in episodes caused by ESBL- and carbapenemase-producing E. coli or K. pneumoniae, with a decline in those caused by methicillin-resistant S. aureus. A spike in BSI episodes, fungal BSIs and catheter-related infections was detected in 2020, during the COVID-19 outbreak.

CONCLUSIONS

No clear increase in the incidence of BSI episodes was detected in our center over this period. Gram-negatives are the most frequent etiology, with no clear rise in antimicrobial resistance phenotypes. The COVID-19 pandemic accounted for a small increase in BSI episodes in 2020, probably related to the increase of catheter-related infections.

Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort

OBJECTIVES

This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP).

METHODS

Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately.

RESULTS

We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors.

CONCLUSION

Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective.

Non-nosocomial Healthcare-Associated Infective Endocarditis: A Distinct Entity? Data From the GAMES Series (2008-2021)

Background

Patients who acquire infective endocarditis (IE) following contact with the healthcare system, but outside the hospital, are classified as having non-nosocomial healthcare-associated IE (HCIE). Our aim was to characterize HCIE and establish whether its etiology, diagnosis, and therapeutic approach suggest it should be considered a distinct entity.

Methods

This study retrospectively analyzes data from a nationwide, multicenter, prospective cohort including consecutive cases of IE at 45 hospitals across Spain from 2008 to 2021. HCIE was defined as IE detected in patients in close contact with the healthcare system (eg, patients receiving intravenous treatment, hemodialysis, or institutionalized). The prevalence and main characteristics of HCIE were examined and compared with those of community-acquired IE (CIE) and nosocomial IE (NIE) and with literature data.

Results

IE was diagnosed in 4520 cases, of which 2854 (63%) were classified as CIE, 1209 (27%) as NIE, and 457 (10%) as HCIE. Patients with HCIE showed a high burden of comorbidities, a high presence of intravascular catheters, and a predominant staphylococcal etiology, Staphylococcus aureus being identified as the most frequent causative agent (35%). They also experienced more persistent bacteremia, underwent fewer surgeries, and showed a higher mortality rate than those with CIE (32.4% vs 22.6%). However, mortality in this group was similar to that recorded for NIE (32.4% vs 34.9%, respectively, P = .40).

Conclusions

Our data do not support considering HCIE as a distinct entity. HCIE affects a substantial number of patients, is associated with a high mortality, and shares many characteristics with NIE.

Enhancing physicians' radiology diagnostics of COVID-19's effects on lung health by leveraging artificial intelligence

Introduction: This study aimed to develop an individualized artificial intelligence model to help radiologists assess the severity of COVID-19's effects on patients' lung health. Methods: Data was collected from medical records of 1103 patients diagnosed with COVID-19 using RT- qPCR between March and June 2020, in Hospital Madrid-Group (HM-Group, Spain). By using Convolutional Neural Networks, we determine the effects of COVID-19 in terms of lung area, opacities, and pulmonary air density. We then combine these variables with age and sex in a regression model to assess the severity of these conditions with respect to fatality risk (death or ICU). Results: Our model can predict high effect with an AUC of 0.736. Finally, we compare the performance of the model with respect to six physicians' diagnosis, and test for improvements on physicians' performance when using the prediction algorithm. Discussion: We find that the algorithm outperforms physicians (39.5% less error), and thus, physicians can significantly benefit from the information provided by the algorithm by reducing error by almost 30%.

Effect of EARLY administration of DEXamethasone in patients with COVID-19 pneumonia without acute hypoxemic respiratory failure and risk of development of acute respiratory distress syndrome (EARLY-DEX COVID-19): study protocol for a randomized controlled trial

Background

Corticosteroids are one of the few drugs that have shown a reduction in mortality in coronavirus disease 2019 (COVID-19). In the RECOVERY trial, the use of dexamethasone reduced 28-day mortality compared to standard care in hospitalized patients with suspected or confirmed COVID-19 requiring supplemental oxygen or invasive mechanical ventilation. Evidence has shown that 30% of COVID-19 patients with mild symptoms at presentation will progress to acute respiratory distress syndrome (ARDS), particularly patients in whom laboratory inflammatory biomarkers associated with COVID-19 disease progression are detected. We postulated that dexamethasone treatment in hospitalized patients with COVID-19 pneumonia without additional oxygen requirements and at risk of progressing to severe disease might lead to a decrease in the development of ARDS and thereby reduce death.

Methods/design

This is a multicenter, randomized, controlled, parallel, open-label trial testing dexamethasone in 252 adult patients with COVID-19 pneumonia who do not require supplementary oxygen on admission but are at risk factors for the development of ARDS. Risk for the development of ARDS is defined as levels of lactate dehydrogenase > 245 U/L, C-reactive protein > 100 mg/L, and lymphocyte count of < 0.80 × 10⁹/L. Eligible patients will be randomly assigned to receive either dexamethasone or standard of care. Patients in the dexamethasone group will receive a dose of 6 mg once daily during 7 days. The primary outcome is a composite of the development of moderate or more severe ARDS and all-cause mortality during the 30-day period following enrolment.

Discussion

If our hypothesis is correct, the results of this study will provide additional insights into the management and progression of this specific subpopulation of patients with COVID-19 pneumonia without additional oxygen requirements and at risk of progressing to severe disease.

Trial registration

ClinicalTrials.gov NCT04836780. Registered on 8 April 2021 as EARLY-DEX COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06722-x.

Unresolved issues in the epidemiology and diagnosis of bacteremia: an opinion paper

Bacteremia is an important cause of morbidity and mortality worldwide and, despite the diagnostic and therapeutic advances of the last decades, the evidence supporting many diagnostic aspects of bacteremia is scarce. Information on the epidemiological evolution of this entity is limited and many methodological aspects of blood culture collection and analysis are under discussion. Furthermore, the recommendations of the main scientific societies on many of these aspects are variable and, in many cases, have not been updated recently. In this scenario, we have arranged a series of questions on different aspects of bacteremia and reviewed the literature trying to find proper answers for them. We offer our opinion on the topics where the evidence was weak. The topics covered include epidemiological aspects of bacteremia, indications for blood culture extraction, methods for obtaining and incubating samples, or ways of transmitting results from the microbiology laboratory. We do not intend to summarize the current clinical practice guidelines, nor will we deal with the therapeutic management of this entity. The aim of this paper is to review the current perspective on the diagnosis of bacteremia with a critical approach, to point out the gaps in the literature, to offer the opinion of a team dedicated to infectious diseases and clinical microbiology, and to identify some areas of knowledge on which future studies should focus.