Coronavirus disease 2019 (COVID-19): Secondary bacterial infections and the impact on antimicrobial resistance during the COVID-19 pandemic

The "COVID effect" in culture-based clinical microbiology: Changes induced by COVID-19 pandemic in a Hungarian tertiary care center

BACKGROUND

The presence of bacterial and fungal coinfections plays an important role in the mortality of patients with coronavirus 2019 (COVID-19). We compared data from the 3 years before and 3 years after the COVID-19 pandemic outbreak to evaluate its effect on the traits of bacterial and fungal diseases.

METHODS

We retrospectively collected and analyzed data on positive respiratory tract samples (n = 13,133 samples from 7717 patients) and blood cultures (n = 23,652 from 9653 patients) between 2017 and 2022 from the Clinical Center of the University of Szeged, Hungary. We also evaluated antimicrobial susceptibility test results derived from 169,020 respiratory samples and 549,729 blood cultures to gain insight into changes in antimicrobial resistance.

RESULTS

The most common respiratory pathogen in the pre-COVID era was Pseudomonas aeruginosa, whereas Candida albicans was the most frequent during the pandemic. The number of respiratory isolates of Acinetobacter baumannii was also markedly increased. In blood cultures, Staphylococcus epidermidis, Escherichia coli, and S. aureus were dominant during the study period, and A. baumannii was widespread in blood cultures during the pandemic years. Resistance to ofloxacin, penicillin, piperacillin-tazobactam, ceftazidime, cefepime, imipenem, ceftolozane-tazobactam, and itraconazole increased significantly in the COVID era.

CONCLUSIONS

During the COVID-19 pandemic, there were changes in the prevalence of respiratory and blood culture pathogens at the Clinical Center of the University of Szeged. C. albicans became the predominant respiratory pathogen, and the number of A. baumannii isolates increased dramatically. Additionally, antimicrobial resistance notably increased during this period.

Histological Assessment of Respiratory Tract and Liver of BALB/c Mice Nebulized with Tocilizumab

Pulmonary drug delivery offers a minimally invasive and efficient method for treating lung conditions, leveraging the lungs' extensive surface area and blood flow for rapid drug absorption. Nebulized therapies aim to deliver drugs directly to the lung tissue. This study investigates the histological impact of nebulized tocilizumab-a monoclonal antibody targeting IL-6, traditionally administered intravenously for rheumatoid arthritis and severe COVID-19-on a murine model. Thirty BALB/c mice were nebulized with tocilizumab (10 mg, 5 mg, and 2.5 mg) and six controls were nebulized with saline solution. They were euthanized 48 h later, and their organs (lungs, nasal mucosa, and liver) were analyzed by a microscopic histological evaluation. The results indicate that all the mice survived the 48 h post-nebulization period without systemic compromise. The macroscopic examination showed no abnormalities, and the histopathological analysis revealed greater lung vascular changes in the control group than in the nebulized animals, which is attributable to the euthanasia with carbon dioxide. Additionally, increased alveolar macrophages were observed in the nebulized groups compared to controls. No significant histological changes were observed in the liver, indicating the safety of nebulized tocilizumab. In conclusion, these findings suggest the potential of nebulized tocilizumab for treating pulmonary inflammation, warranting further research to establish its efficacy and safety in clinical settings.

SARS-CoV-2 and Influenza Co-Infection: Fair Competition or Sinister Combination?

The COVID-19 pandemic remains a serious public health problem globally. During winter influenza seasons, more aggressive SARS-CoV-2 infections and fatalities have been documented, indicating that influenza co-infections may significantly impact the disease outcome of COVID-19. Both influenza and SARS-CoV-2 viruses share many similarities in their transmission and their cellular tropism for replication in the human respiratory tract. However, the complex intricacies and multi-faceted dynamics of how the two pathogens interact to ensure their survival in the same lung microenvironment are still unclear. In addition, clinical studies on influenza co-infections in COVID-19 patients do not provide conclusive evidence of how influenza co-infection mechanistically modifies disease outcomes of COVID-19. This review discusses various viral as well as host factors that potentially influence the survival or synergism of these two respiratory pathogens in the infected lung microenvironment.

Development and validation of machine learning-based models for predicting healthcare-associated bacterial/fungal infections among COVID-19 inpatients: a retrospective cohort study

BACKGROUND

COVID-19 and bacterial/fungal coinfections have posed significant challenges to human health. However, there is a lack of good tools for predicting coinfection risk to aid clinical work.

OBJECTIVE

We aimed to investigate the risk factors for bacterial/fungal coinfection among COVID-19 patients and to develop machine learning models to estimate the risk of coinfection.

METHODS

In this retrospective cohort study, we enrolled adult inpatients confirmed with COVID-19 in a tertiary hospital between January 1 and July 31, 2023, in China and collected baseline information at admission. All the data were randomly divided into a training set and a testing set at a ratio of 7:3. We developed the generalized linear and random forest models for coinfections in the training set and assessed the performance of the models in the testing set. Decision curve analysis was performed to evaluate the clinical applicability.

RESULTS

A total of 1244 patients were included in the training cohort with 62 healthcare-associated bacterial/fungal infections, while 534 were included in the testing cohort with 22 infections. We found that patients with comorbidities (diabetes, neurological disease) were at greater risk for coinfections than were those without comorbidities (OR = 2.78, 95%CI = 1.61-4.86; OR = 1.93, 95%CI = 1.11-3.35). An indwelling central venous catheter or urinary catheter was also associated with an increased risk (OR = 2.53, 95%CI = 1.39-4.64; OR = 2.28, 95%CI = 1.24-4.27) of coinfections. Patients with PCT > 0.5 ng/ml were 2.03 times (95%CI = 1.41-3.82) more likely to be infected. Interestingly, the risk of coinfection was also greater in patients with an IL-6 concentration < 10 pg/ml (OR = 1.69, 95%CI = 0.97-2.94). Patients with low baseline creatinine levels had a decreased risk of bacterial/fungal coinfections(OR = 0.40, 95%CI = 0.22-0.71). The generalized linear and random forest models demonstrated favorable receiver operating characteristic curves (ROC = 0.87, 95%CI = 0.80-0.94; ROC = 0.88, 95%CI = 0.82-0.93) with high accuracy, sensitivity and specificity of 0.86vs0.75, 0.82vs0.86, 0.87vs0.74, respectively. The corresponding calibration evaluation P statistics were 0.883 and 0.769.

CONCLUSIONS

Our machine learning models achieved strong predictive ability and may be effective clinical decision-support tools for identifying COVID-19 patients at risk for bacterial/fungal coinfection and guiding antibiotic administration. The levels of cytokines, such as IL-6, may affect the status of bacterial/fungal coinfection.

Knowledge, attitudes, and practices regarding antibiotic use among the population of the Republic of Serbia - A cross-sectional study

BACKGROUND

Antimicrobial resistance presents one of the most significant threats to public health. This study aimed to examine antibiotic usage within the general population in the Republic of Serbia and their knowledge, attitudes, and behavior concerning this topic.

METHODS

We conducted an online cross-sectional study over two weeks in December 2022, on a sample of 1014 respondents, representative of the Republic of Serbia's population. Predictors of the Antibiotic Knowledge Score (composed of four questions) were analyzed by multivariate ordinal logistic regression.

RESULTS

In 2022, 76.8% of the participants from the Serbian population had taken antibiotics, mostly upon a medical prescription, with the most common reasons being upper respiratory tract infections. Only 31.3% of all respondents received any kind of advice about the rational use of antibiotics and half of them changed their opinions on using antibiotics after receiving this information. The average Antibiotic Knowledge Score was 2.6 out of 4, with 32.5% of respondents answering all knowledge questions correctly. The multivariate ordinal logistic regression analysis showed that female gender, higher education level, and the willingness to change opinions regarding the usage of antibiotics after receiving information about the rational use of antibiotics from any available source were significant predictors of better knowledge about antibiotics use. Respondents who were open to changing their opinion after receiving information about the rational use of antibiotics had 28% higher odds of higher antibiotic knowledge scores.

CONCLUSION

This is the first population-level study on public knowledge, attitudes, and practices about antibiotic use in Serbia and therefore the baseline for future research and measuring the impact of potential interventions. Our findings underline the importance of taking into account specific population characteristics, knowledge levels, and attitudes when designing educational and intervention strategies for antibiotic use. Policymakers can leverage these findings to target specific groups and enhance the population's knowledge and practices regarding rational antibiotic usage.

The emergence of multidrug-resistant bacteria causing healthcare-associated infections in COVID-19 patients - a retrospective multi-centre study

INTRODUCTION

We evaluated the prevalence, aetiologies and antibiotic resistance patterns of bacterial infections in hospitalized patients with laboratory-confirmed SARS-CoV-2. We also investigated comorbidities, risk factors, and the mortality rate in COVID-19 patients with bacterial infections.

METHODS

This retrospective observational study evaluated medical records of 7249 randomly selected patients with COVID-19 admitted to three clinical centres between January 1 2021 and February 16, 2022. A total of 6478 COVID-19 patients met the eligibility criteria for analysis.

RESULTS

The mean age of the patients with SARS-CoV-2 and bacterial infections was 68.6 ± 15.5 years (range: 24 to 94 years). The majority of patients (68.7%) were older than 65 years. The prevalence of bacterial infections among hospitalized COVID-19 patients was 12.9%, most of them being hospital-acquired (11.5%). Bloodstream (37.7%) and respiratory tract infections (25.6%) were the most common bacterial infections. Klebsiella pneumoniae and Acinetobacter baumannii caused 25.2% and 23.6% of all bacterial infections, respectively. Carbapenem-resistance in Enterobacterales, A. baumannii, and Pseudomonas aeruginosa were 72.6%, 93.7%, and 69.1%. Age >60 years and infections caused by ≥3 pathogens were significantly more prevalent among deceased patients compared to survivors (p<0.05). Furthermore, 95% of patients who were intubated developed ventilator-associated pneumonia. The overall in-hospital mortality rate of patients with SARS-CoV-2 and bacterial infections was 51.6%, while 91.7% of patients who required invasive mechanical ventilation died.

CONCLUSIONS

Our results reveal a striking association between healthcare-associated bacterial infections as an important complication of COVID-19 and fatal outcomes.