Diagnostic significance of secondary bacteremia in patients with COVID-19

Candidemia Following Severe COVID-19 in Hospitalised and Critical Ill Patients: A Systematic Review and Meta-Analysis

RATIONALE

The epidemiology and clinical impact of COVID-19-associated candidemia (CAC) remained uncertain, leaving gaps in understanding its prevalence, risk factors and outcomes.

METHODS

A systematic review and meta-analysis were conducted by searching PubMed, Embase and Scopus for reports of CAC prevalence, risk factors and clinical outcomes up to June 18, 2024. The generalised linear mixed model was employed to determine the prevalence and 95% confidence intervals (CIs). The risk factors and clinical outcomes were compared between patients with and without CAC using the inverse variance method.

RESULTS

From 81 studies encompassing 29 countries and involving 351,268 patients, the global prevalence of CAC was 4.33% (95% Cl, 3.16%-5.90%) in intensive care unit (ICU) patients. In ICUs, the pooled prevalence of CAC in high-income countries was significantly higher than that of lower-middle-income countries (5.99% [95% Cl, 4.24%-8.40%] vs. 2.23% [95% Cl, 1.06%-4.61%], p = 0.02). Resistant Candida species, including C. auris, C. glabrata (Nakaseomyces glabratus) and C. krusei (Pichia kudriavzveii), constituted 2% of ICU cases. The mortality rate for CAC was 68.40% (95% Cl, 61.86%-74.28%) among ICU patients. Several risk factors were associated with CAC, including antibiotic use, central venous catheter placement, dialysis, mechanical ventilation, tocilizumab, extracorporeal membrane oxygenation and total parenteral nutrition. Notably, the pooled odds ratio of tocilizumab was 2.59 (95% CI, 1.44-4.65).

CONCLUSIONS

The prevalence of CAC is substantial in the ICU setting, particularly in high-income countries. Several risk factors associated with CAC were identified, including several that are modifiable, offering the opportunity to mitigate the risk of CAC.

Bacterial co-infection in COVID-19: a call to stay vigilant

Co-infection with diverse bacteria is commonly seen in patients infected with the novel coronavirus, SARS-CoV-2. This type of co-infection significantly impacts the occurrence and development of novel coronavirus infection. Bacterial co-pathogens are typically identified in the respiratory system and blood culture, which complicates the diagnosis, treatment, and prognosis of COVID-19, and even exacerbates the severity of disease symptoms and increases mortality rates. However, the status and impact of bacterial co-infections during the COVID-19 pandemic have not been properly studied. Recently, the amount of literature on the co-infection of SARS-CoV-2 and bacteria has gradually increased, enabling a comprehensive discussion on this type of co-infection. In this study, we focus on bacterial infections in the respiratory system and blood of patients with COVID-19 because these infection types significantly affect the severity and mortality of COVID-19. Furthermore, the progression of COVID-19 has markedly elevated the antimicrobial resistance among specific bacteria, such as Klebsiella pneumoniae, in clinical settings including intensive care units (ICUs). Grasping these resistance patterns is pivotal for the optimal utilization and stewardship of antibiotics, including fluoroquinolones. Our study offers insights into these aspects and serves as a fundamental basis for devising effective therapeutic strategies. We primarily sourced our articles from PubMed, ScienceDirect, Scopus, and Google Scholar. We queried these databases using specific search terms related to COVID-19 and its co-infections with bacteria or fungi, and selectively chose relevant articles for inclusion in our review.

Examining the influence of Covid-19 restrictions, a nurse strike, and SARS-CoV-2 coinfection on bacteremia mortality: A Danish population-based cohort study (2019-2022)

Objectives

Bacteremia is an acute severe infection with high mortality. Changes in healthcare services and coinfections with SARS-CoV-2 may have affected the mortality for bacteremia during the COVID-19 pandemic, which has been reported for other major diseases. In this study we examine the all-cause bacteremia mortality amidst the COVID-19 pandemic.

Methods

A population-based cohort study comprised of laboratory confirmed bacteremia episodes in the Capital Region, Denmark (March 2019-February 2022). Cox proportional hazards models were used to calculate hazard ratios (HR) and 95 % confidence intervals (CI) for all-cause bacteremia mortality associated with the Covid-19 restriction period, a strike period, and coinfection with SARS-CoV-2, adjusted for possible confounders.

Results

A total of 14,912 bacteremia episodes were identified in 12,693 patients during the study period. The 30- and 90-day all-cause mortality were 19 % and 27 %, respectively. The fully adjusted HR for 30- and 90-day all-cause mortality associated with the Covid-19 restriction period were 0.91 (95 % CI, 0.84 to 0.99) and 0.90 (95 % CI, 0.84 to 0.96), respectively, compared to the remaining time period. The corresponding HRs associated with SARS-CoV-2 coinfection were 1.29 (95 % CI, 1.11 to 1.50) and 1.36 (95 % CI, 1.20 to 1.55) compared to patients without coinfection. The association between the national nurse strike and all-cause bacteremia mortality was inconclusive.

Conclusions

In this large population-based cohort study, a significant reduction in all-cause mortality for bacteremia was observed during the Covid-19 restriction period in Denmark, while coinfection with SARS-CoV-2 seem to be a substantial risk factor for all-cause bacteremia mortality.

CT-derived vertebral bone mineral density is a useful biomarker to predict COVID-19 outcome

The low vertebral bone computed tomography (CT) Hounsfield unit values measured on CT scans reflect low bone mineral density (BMD) and are known as diagnostic indicators for osteoporosis. The potential prognostic significance of low BMD defined by vertebral bone CT values for the coronavirus disease 2019 (COVID-19) remains unclear. This study aimed to assess the impact of BMD on the clinical outcome in Japanese patients with COVID-19 and evaluate the association between BMD and critical outcomes, such as high-flow nasal cannula, non-invasive and invasive positive pressure ventilation, extracorporeal membrane oxygenation, or death. We examined the effects of COVID-19 severity on the change of BMD over time. This multicenter retrospective cohort study enrolled 1132 inpatients with COVID-19 from the Japan COVID-19 Task Force database between February 2020 and September 2022. The bone CT values of the 4th, 7th, and 10th thoracic vertebrae were measured from chest CT images. The average of these values was defined as BMD. Furthermore, a comparative analysis was conducted between the BMD on admission and its value 3 months later. The low BMD group had a higher proportion of critical outcomes than did the high BMD group. In a subanalysis stratifying patients by epidemic wave according to onset time, critical outcomes were higher in the low BMD group in the 1st-4th waves. Multivariable logistic analysis of previously reported factors associated with COVID-19 severity revealed that low BMD, chronic kidney disease, and diabetes were independently associated with critical outcomes. At 3 months post-infection, patients with oxygen demand during hospitalization showed markedly decreased BMD than did those on admission. Low BMD in patients with COVID-19 may help predict severe disease after the disease onset. BMD may decrease over time in patients with severe COVID-19, and the impact on sequelae symptoms should be investigated in the future.

Corticosteroid Dosing Level, Incidence and Profile of Bacterial Blood Stream Infections in Hospitalized COVID-19 Patients

COVID-19 patients with severe or critical symptoms are often treated with corticosteroids, per contemporary guidelines. Due to their immunosuppressive and immunomodulatory properties, corticosteroids are associated with the development of superinfections. We aimed to retrospectively assess patterns of corticosteroid use and the profiles of bacterial blood stream infections associated with exposure to different dosing levels, in a cohort of 1558 real-life adult COVID-19 patients. A total of 1391 (89.3%) patients were treated with corticosteroids, with 710 (45.6%) patients receiving low, 539 (34.6%) high and 142 (9.1%) very high corticosteroid doses. Bacteremia developed in a total of 178 (11.4%) patients. The risk of bacteremia was of similar magnitude between the no and low-dose corticosteroid treatments (p = 0.352), whereas it progressively increased with high (OR 6.18, 95% CI (2.66-14.38), p < 0.001) and very high corticosteroid doses (OR 8.12, 95% CI (3.29-20.05), p < 0.001), compared to no corticosteroid treatment. These associations persisted after multivariate adjustments and were present independently of sex, comorbidity burden, and mechanical ventilation. The profiles of individual bacterial pathogens differed depending on the used corticosteroid doses. High and very high corticosteroid doses are frequently used for real-life COVID-19 patients with severe and critical clinical presentations and are associated with a higher risk of bacteremia independently of sex, comorbidity burden, and mechanical ventilation use.

Identification of risk factors and development of a predictive model for bloodstream infection in intensive care unit COVID-19 patients

OBJECTIVES

To identify risk factors for nosocomial bloodstream infections (BSIs) in intensive care unit (ICU) patients with COVID-19 and to build a predictive model for BSIs.

PATIENTS AND METHODS

The retrospective case-control study included 236 ICU COVID-19 patients with BSIs group and 234 patients in the control group. Demographic and laboratory data, comorbidities, drug use, invasive procedures and identified pathogens were recorded separately for patients directly admitted and transferred to ICU. Fine and Gray's multi-variate competing risk model was used to build a predictive model for patients transferred to ICU.

RESULTS

The risk factors were: interleukin inhibitors (HR = 6.1 (95% CI: 2.0-18.5)) and dexamethasone (HR = 3.0 (95% CI: 1.3-7.1)) use in previous hospitalization, glomerular filtration rate <60 mL/min per 1.73 m2 (HR = 4.0 (95% CI: 2.1-7.6)) and blood glucose >9 mmol/L (HR = 2.5 (95% CI: 1.4-4.6)) in patients directly admitted to ICU; and dexamethasone use in previous hospitalization (HR = 4.5 (95% CI: 1.8-11)), the total dexamethasone dose before transfer to ICU (HR = 1.2 (95% CI: 1.06-1.37)), diabetes mellitus (HR = 1.4 (95% CI: 1.1-1.9)), alanine transaminase (ALT) ≥35.5 U/L on hospital admission (HR = 1.5 (95% CI: 1.1-2.1)), and the use of low-flow oxygen versus high-flow oxygen therapy or non-invasive mechanical ventilation on admission to ICU ((HR = 2.7 (95% CI: 5.6-11.1)) in patients transferred to ICU. A predictive model had sensitivity of 63-73% and specificity of 71-83% at different times of ICU stay.

CONCLUSIONS

Our findings may help clinicians detect patients at high risk of developing BSIs.