ABSTRACT
BACKGROUND: The role of bacterial co-infection and superinfection among critically ill COVID-19 patients remains unclear. The aim of this study was to assess the rates and characteristics of pulmonary infections, and associated outcomes of ventilated patients in our facility. METHODS: This was a retrospective study of ventilated COVID-19 patients between March 2020 and March 2021 that underwent BioFire®, FilmArray® Pneumonia Panel, testing. Community-acquired pneumonia (CAP) was defined when identified during the first 72 h of hospitalization, and ventilator-associated pneumonia (VAP) when later. RESULTS: 148 FilmArray tests were obtained from 93 patients. With FilmArray, 17% of patients had CAP (16/93) and 68% had VAP (64/93). Patients with VAP were older than those with CAP or those with no infection (68.5 vs. 57-59 years), had longer length of stay and higher mortality (51% vs. 10%). The most commonly identified FilmArray target organisms were H. influenzae, S. pneumoniae, M. catarrhalis and E. cloacae for CAP and P. aeruginosa and S. aureus for VAP. FilmArray tests had high negative predictive values (99.6%) and lower positive predictive values (~60%). CONCLUSIONS: We found high rates of both CAP and VAP among the critically ill, caused by the typical and expected organisms for both conditions. VAP diagnosis was associated with poor patient outcomes.
ABSTRACT
BACKGROUND: The role of bacterial and viral co-infection in the current COVID-19 pandemic remains elusive. The aim of this study was to describe the rates and features of co-infection on admission of COVID-19 patients, based on molecular and routine laboratory methods. METHODS: A retrospective study of COVID-19 and non-COVID-19 patients undergoing Biofire®, FilmArray® Pneumonia Panel, bioMérieux, and routine cultures during the first 3 days from admission, between June 2019 and March 2021. RESULTS: FilmArray tests were performed in 115 COVID-19 and in 61 non-COVID-19 patients. Most (>99%) COVID-19 patients had moderate-critical illness, 37% required mechanical ventilation. Sputa and endotracheal aspirates were the main samples analyzed. Positive FilmArray tests were found in 60% (70/116) of the tests amongst COVID-19 patients and 62.5% (40/64) amongst non-COVID-19 patients. All 70 cases were positive for bacterial targets, while one concomitant virus (Rhinovirus/Enterovirus) and one Legionella spp. were detected. The most common bacterial targets were Haemophilus influenzae (36%), Staphylococcus aureus (23%), Streptococcus pneumoniae (10%) and Enterobacter cloacae (10%). Correlation between FilmArray and cultures was found in 81% and 44% of negative and positive FA tests, respectively. Positive FilmArray results typically (81%) triggered the administration of antibiotic therapy and negative results resulted in antimicrobials to be withheld in 56% of cases and stopped in 8%. Bacterial cultures of COVID-19 patients were positive in 30/88 (34%) of cases. CONCLUSIONS: Bacterial co-infection is common amongst moderate-critical COVID-19 patients on admission while viral and atypical bacteria were exceedingly rare. Positive FilmArray results could trigger potentially unnecessary antibiotic treatment.KEY POINTWe found high rates of on-admission bacterial co-infection amongst hospitalized moderate to severe COVID-19 patients. Molecular tests (Biofire, FilmArray) and routine microbiological tests revealed 60% and 34% bacterial co-infection, respectively, while viral and fungal co-infections were rare.