SARS-CoV-2 Pneumonia Has Low Prevalence of Bacterial Identification

Early empirical antimicrobial treatment is often prescribed to hospitalized patients with COVID-19, but findings from a study published in the American Journal of Respiratory and Critical Care Medicine suggest the prevalence of early bacterial identification is up to 3-fold lower in intubated patients with SARS-CoV-2 pneumonia compared with patients with influenza pneumonia.

Researchers retrospectively examined a European cohort of 1050 patients across 36 intensive care units (ICUs). A total of 568 patients had SARS-CoV-2 pneumonia while 482 had influenza pneumonia. All patients received invasive mechanical ventilation for more than 48 hours prior to study entry, and 88.5% of patients in both groups received antibiotics at ICU admission.

The study authors compared the groups regarding the rate of early bacterial identification, defined by a positive bacterial culture less than 48 hours following intubation. Positive bacterial cultures were identified in bronchoalveolar lavage, blood cultures, endotracheal aspirates, or a positive pneumococcal or legionella urinary antigen test.

A significant lower percentage of patients with SARS-CoV-2 pneumonia had bacterial identification vs patients with influenza pneumonia (9.7% vs 33.6%, respectively; adjusted odds ratio, 0.23; 95% CI, 0.16-0.33; P <.0001). Gram-positive cocci caused 58% of co-infections in patients with SARS-CoV-2 and 72% of co-infections in patients with influenza pneumonia. A significantly higher 28-day mortality was observed in patients with SARS-CoV-2 pneumonia and bacterial identification (hazard ratio, 1.57; 95% CI, 1.01-2.44; P =.043).

Limitations of this study include its retrospective design as well as the high percentage of patients who were receiving antibiotics at time of respiratory sample collection.

The researchers suggested that clinicians “carefully evaluate the indication of early empirical antimicrobial treatment in this population.” They added that further research needed to better “assess the feasibility and safety of antibiotic stewardship strategies in critically ill patients with COVID-19.”

Reference

Rouze A, Martin-Loeches I, Povoa P, et al; on behalf of the coVAPid Study Group. Early bacterial identification among intubated patients with COVID-19 or influenza pneumonia: a European multicenter comparative cohort study. Published online May 26, 2021. Am J Respir Crit Care Med. doi:10.1164/rccm.202101-0030OC