Bacterial coinfection in the critically-ill COVID-19 patient: incidence, impact and need for antimicrobial therapy

Abstract

Objectives. To assess the frequency of bacterial coinfection upon ICU admission in SARS-CoV-2 pneumonia patients, its microbiology, and impact on prognosis.The secondary objective was to identify risk factors for coinfection on admission. Methods. Retrospective study, including patients with SARS-CoV-2 pneumonia admitted to the ICU.We defined bacterial coinfection by respiratory symptoms, radiological data, positive and clinically significant microbiological results in samples obtained in the first 48 h of admission and/or a determination of procalcitonin ≥ 0.5 ng/mL in the first 48 h.We evaluated demographic variables, comorbidities, SARS-CoV-2 infection data, severity scores, treatments received, need for respiratory support and outcomes (ICU and hospital mortality). Results. A total of 182 patients were analyzed, 62 (34.1%) with bacterial coinfection.The most frequent microbiology was S. pneumoniae and M. pneumoniae. 96.1% of the patients received antibiotic therapy on admission, 98.9% corticosteroids, 27.5% tocilizumab, and 7.7% remdesivir.85.7% required invasive mechanical ventilation.The SOFA score (OR: 1.315, 95% CI1.116-1.548) and the delay in ICU admission (OR: 0.899, 95% CI 0.831-0.972) were related to the risk of coinfection. Bacterial coinfection increases the risk of death in hospital (OR 2.283; 95% CI 1.011.5.151; p=0.047). Conclusions. Bacterial coinfection is common in COVID patients admitted to the ICU and increases the risk of death. It is not possible to identify with certainty, at the time of admission, which patients do not benefit from antibiotic treatment.