Risk factors associated with bacteremia in COVID-19 patients admitted to intensive care unit: a retrospective multicenter cohort study

Risk factors for bloodstream infection in COVID-19 patients in intensive care units: a systematic review and meta-analysis

BACKGROUND

Risk factors for bloodstream infection in patients with COVID-19 in the intensive care unit (ICU) remain unclear. The purpose of this systematic review was to study the risk factors for BSI in patients admitted to ICUs for COVID-19.

METHODS

A systematic search was performed on PubMed, EMBASE, Cochrane Library, and Web of Science up to July 2024. Data were reported as combined odds ratio (OR) for categorical variables and weighted mean difference (WMD) for continuous variables.

RESULTS

6914 studies were retrieved, of which 55 were included in the meta-analysis. Men (OR = 1.28, 95% CI: 1.10-1.50, P = 0.006), high SAPS II score (WMD = 6.43, 95% CI: 0.23-12.63, P = 0.042), diabetes (OR = 1.34, 95% CI: 1.04-1.73, P = 0.022), tracheal intubation (OR = 8.68, 95% CI: 4.68-16.08, P < 0.001), mechanical ventilation (OR = 22.00, 95% CI: 3.77-128.328, P < 0.001), ECMO (OR = 2.70, 95% CI: 1.17-6.26, P = 0.020), central venous cannulation (OR = 9.33, 95% CI: 3.06-28.43, P < 0.001), prolonged ICU stay (WMD = 10.37, 95% CI: 9.29-11.44, P < 0.001), methylprednisolone use (OR = 2.24, 95% CI: 1.24-4.04, P = 0.008), and the combination of methylprednisolone and Tocilizumab (OR = 4.54, 95% CI: 1.09-18.88, P = 0.037) were risk factors for ICU-BSI in COVID-19 patients.

CONCLUSION

We identified 10 risk factors for ICU-BSI in COVID-19 patients. In future studies, these factors can be combined to establish a more comprehensive and accurate prediction model for ICU-BSI in COVID-19 patients. Targeted measures can be taken earlier to control BSI.

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.

Bloodstream infections in the era of the COVID-19 pandemic: Changing epidemiology of antimicrobial resistance in the intensive care unit

The Coronavirus disease 2019 (COVID-19) pandemic increased the burden of critically ill patients who required hospitalization in the intensive care unit (ICU). Bacterial and fungal co-infections, including bloodstream infections (BSIs), increased significantly in ICU patients with COVID-19; this had a significant negative impact on patient outcomes. Reported data pertaining to BSI episodes from the ICU setting during the COVID-19 pandemic were collected and analyzed for this narrative review. We searched the PubMed database for articles published between March 2020 and October 2023; the terms "COVID-19" AND "bloodstream infections" AND "ICU" were used for the search. A total of 778 articles were retrieved; however, only 27 were exclusively related to BSIs in ICU patients with COVID-19. Data pertaining to the epidemiological characteristics, risk factors, characteristics of bacterial and fungal BSIs, patterns of antimicrobial resistance, and comparisons between ICU and non-ICU patients during and before the COVID-19 pandemic were obtained. Data on antimicrobial stewardship and infection-control policies were also included. The rates of BSI were found to have increased among ICU patients with COVID-19 than in non-COVID-19 patients and those admitted during the pre-pandemic period. Male gender, 60-70 years of age, increased body mass index, high Sequential Organ Failure Assessment scores at admission, prolonged hospital and ICU stay, use of central lines, invasive ventilation, and receipt of extracorporeal membrane oxygenation were all defined as risk factors for BSI. The use of immune modulators for COVID-19 appeared to increase the risk of BSI; however, the available data are conflicting. Overall, Enterococci, Acinetobacter baumannii, and Candida spp. emerged as prominent infecting organisms during the pandemic; along with Enterobacterales and Pseudomonas aeruginosa they had a significant impact on mortality. Multidrug-resistant organisms prevailed in the ICU, especially if antimicrobial resistance was established before the COVID-19 pandemic and were significantly associated with increased mortality rates. The unnecessary and widespread use of antibiotics further increased the prevalence of multidrug-resistant organisms during COVID-19. Notably, the data indicated a significant increase in contaminants in blood cultures; this highlighted the decline in compliance with infection-control measures, especially during the initial waves of the pandemic. The implementation of infection-control policies along with antibiotic stewardship succeeded in significantly reducing the rates of blood contamination and BSI pathogens. BSIs considerably worsened outcomes in patients with COVID-19 who were admitted to ICUs. Further studies are needed to evaluate adequate preventive and control measures that may increase preparedness for 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.

Bloodstream Infections in Intensive Care Unit during Four Consecutive SARS-CoV-2 Pandemic Waves

Critically ill COVID-19 patients are at an increased risk of bloodstream infections (BSIs). We performed a retrospective observational single-center study on COVID-19 patients admitted to intensive care unit (ICU) to assess the incidence of BSIs in four consecutive periods: 21 February-31 July 2020 (W1), 1 August 2020-31 January 2021 (W2), 1 February-30 September 2021 (W3) and 1 October 2021 and 30 April 2022 (W4). BSIs that occurred 48 h after ICU admission were included. The crude incidence of BSIs was estimated by means of Poisson distribution normalized to 1000 patient-days. A total of 404 critically ill COVID-19 patients were admitted to ICU, of whom 284 (61%) developed at least one episode of BSI with an overall crude incidence of 87 events every 1000 patient-days (95% CI 77-98) without a significant difference in consecutive epidemic periods (p = 0.357). Gram-positive bacteria were the most frequent etiological agents of BSIs, contributing to 74.6% episodes. A progressive decrease in BSIs due to Enterococcus spp. was observed (W1 57.4%, W2 43.7%, W3 35.7% and W4 32.7%; p = 0.004). The incidence of BSIs remained stable during different epidemic periods. Enterococcus spp. prevalence was significantly reduced, although still accounted for one third of BSIs in more recent epidemic periods.

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.

An Observational Study to Develop a Predictive Model for Bacterial Pneumonia Diagnosis in Severe COVID-19 Patients-C19-PNEUMOSCORE

In COVID-19 patients, antibiotics overuse is still an issue. A predictive scoring model for the diagnosis of bacterial pneumonia at intensive care unit (ICU) admission would be a useful stewardship tool. We performed a multicenter observational study including 331 COVID-19 patients requiring invasive mechanical ventilation at ICU admission; 179 patients with bacterial pneumonia; and 152 displaying negative lower-respiratory samplings. A multivariable logistic regression model was built to identify predictors of pulmonary co-infections, and a composite risk score was developed using β-coefficients. We identified seven variables as predictors of bacterial pneumonia: vaccination status (OR 7.01; 95% CI, 1.73-28.39); chronic kidney disease (OR 3.16; 95% CI, 1.15-8.71); pre-ICU hospital length of stay ≥ 5 days (OR 1.94; 95% CI, 1.11-3.4); neutrophils ≥ 9.41 × 10⁹/L (OR 1.96; 95% CI, 1.16-3.30); procalcitonin ≥ 0.2 ng/mL (OR 5.09; 95% CI, 2.93-8.84); C-reactive protein ≥ 107.6 mg/L (OR 1.99; 95% CI, 1.15-3.46); and Brixia chest X-ray score ≥ 9 (OR 2.03; 95% CI, 1.19-3.45). A predictive score (C19-PNEUMOSCORE), ranging from 0 to 9, was obtained by assigning one point to each variable, except from procalcitonin and vaccine status, which gained two points each. At a cut-off of ≥3, the model exhibited a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 84.9%, 55.9%, 69.4%, 75.9%, and 71.6%, respectively. C19-PNEUMOSCORE may be an easy-to-use bedside composite tool for the early identification of severe COVID-19 patients with pulmonary bacterial co-infection at ICU admission. Its implementation may help clinicians to optimize antibiotics administration in this setting.

Procalcitonin Values Fail to Track the Presence of Secondary Bacterial Infections in COVID-19 ICU Patients

The development of secondary bacterial infections in COVID-19 patients has been associated with increased mortality and worse clinical outcomes. Consequently, many patients have received empirical antibiotic therapies with the potential to further exacerbate an ongoing antimicrobial resistance crisis. The pandemic has seen a rise in the use of procalcitonin testing to guide antimicrobial prescribing, although its value remains elusive. This single-centre retrospective study sought to analyse the efficacy of procalcitonin in identifying secondary infections in COVID-19 patients and evaluate the proportion of patients prescribed antibiotics to those with confirmed secondary infection. Inclusion criteria comprised patients admitted to the Grange University Hospital intensive care unit with SARS-CoV-2 infection throughout the second and third waves of the pandemic. Data collected included daily inflammatory biomarkers, antimicrobial prescriptions, and microbiologically proven secondary infections. There was no statistically significant difference between PCT, WBC, or CRP values in those with an infection versus those without. A total of 57.02% of patients had a confirmed secondary infection, with 80.2% prescribed antibiotics in Wave 2, compared to 44.07% with confirmed infection and 52.1% prescribed antibiotics in Wave 3. In conclusion, procalcitonin values failed to indicate the emergence of critical care-acquired infection in COVID-19 patients.

Diagnostic significance of secondary bacteremia in patients with COVID-19

OBJECTIVES

We investigated the occurrence of non-respiratory bacterial and fungal secondary infections, causative organisms, impact on clinical outcomes, and association between the secondary pathogens and mortality in hospitalized patients with coronavirus disease 2019 (COVID-19).

METHODS

This was a retrospective cohort study that included data from inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021). We obtained demographic, epidemiological, and microbiological data throughout the course of hospitalization and analyzed the cases of COVID-19 complicated by non-respiratory bacterial infections.

RESULTS

Of the 1914 patients included, non-respiratory bacterial infections with COVID-19 were diagnosed in 81 patients (4.2%). Of these, 59 (3.1%) were secondary infections. Bacteremia was the most frequent bacterial infection, occurring in 33 cases (55.9%), followed by urinary tract infections in 16 cases (27.1%). Staphylococcus epidermidis was the most common causative organism of bacteremia. Patients with COVID-19 with non-respiratory secondary bacterial infections had significantly higher mortality, and a multivariate logistic regression analysis demonstrated that those with bacteremia (aOdds Ratio = 15.3 [5.97-39.1]) were at higher risk of death. Multivariate logistic regression analysis showed that age, male sex, use of steroids to treat COVID-19, and intensive care unit admission increased the risk for nosocomial bacteremia.

CONCLUSIONS

Secondary bacteremia is an important complication that may lead to poor prognosis in cases with COVID-19. An appropriate medical management strategy must be established, especially for patients with concomitant predisposing factors.