Yi-Ting Chena,b*, Ya-Ju Wua, Li-Liang Chuanga, Hui-Sheng Wangc, Yuan-Chieh Changc
aDepartment of Critical Care Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan, bSchool of Medicine, Tzu Chi University, Hualien, Taiwan, cDepartment of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
Open Access funded by Buddhist Compassion Relief Tzu Chi Foundation
Abstract
Objectives: The objective of the study is to understand the prevalence of bacterial coinfection and secondary infection in severe coronavirus disease 2019 (COVID-19) pneumonia in a tertiary hospital intensive care unit (ICU), the spectrum of pathogens, and the impact of these infections on clinical outcomes. Materials and Methods: Retrospective analysis of all patients with COVID-19 with acute hypoxemic respiratory failure who were admitted to the ICU requiring invasive mechanical ventilation (IMV) or high-flow nasal cannula (HFNC) from January 2021 to August 2022. Results: Of the 123 cases, 59.3% had culture-confirmed bacterial co-infection, mostly lower respiratory tract infections (LRTIs). Patients with bacterial co-infection had higher 30-day mortality (28.8% vs. 12%, hazard ratio [HR] = 2.96, %95 confidence interval [CI] =1.1–7.99; adjusted HR [aHR] = 1.34, %95 CI = 0.43–4.17). Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa were the most common co-infection pathogens. Of the 108 cases who stayed in the ICU for >2 days, 34 (31.5%) cases developed secondary bacterial infections within 30 days, of whom all cases had LRTI, 4 had bacteremia, and 8 had urinary tract infections. IMV users had a higher 1-month incidence of secondary bacterial infections than HFNC users (47.5% vs. 8.9%, P < 0.0001). Patients with secondary bacterial infections had higher 60-day mortality (32.4% vs. 11.2% HR = 3.45, 95% CI = 1.27–9.4; aHR = 2.29, %95 CI =0.8–6.67). The most common secondary infection pathogens were Acinetobacter species, P. aeruginosa, Stenotrophomonas maltophilia, and K. pneumoniae. At the 30-day follow-up, 54 events of ICU-acquired secondary bacterial LRTI were noted in 34 patients, 18 (33.3%) events, and 15 (44%) patients were infected by carbapenem-resistant Gramnegative bacilli. Conclusion: The high incidence of bacterial co-infection and secondary infection in critically ill patients with COVID-19 might associated with increased mortality. Infection by drug-resistant pathogens may develop during the treatment course.
Keywords: Acute respiratory failure, Bacterial co-infection, Coronavirus disease 2019, Secondary infection
