Usefulness of blood cultures in COVID-19 pneumonia

The Coronavirus Disease 2019 (COVID-19) pandemic has strained the world's health systems, highlighting the need to optimize its clinical management and treatment. The usefulness of blood cultures in patients with COVID-19 pneumonia has not been proved. We aim to describe the diagnostic yield of early blood cultures in patients with COVID-19 pneumonia in a public hospital in Buenos Aires City. This descriptive observational study included all adult patients with COVID-19 pneumonia admitted to the Internal Medicine ward of Hospital Durand between April 1, 2020 and July 30, 2020, who had blood cultures drawn within 5 days from hospital admission. Among 267 patients hospitalized with COVID-19 pneumonia, 38 had early blood cultures drawn. No clinically relevant microorganism was isolated from blood and contaminant microorganisms were recovered in 7 (18.4%) patients. This study found no evidence of bacteremia in patients with COVID-19 pneumonia. Furthermore, the rate of contaminated blood cultures nearly doubles the reported in patients with community acquired pneumonia (10%), which may be explained by unfamiliarity of additional personal protective equipment worn by healthcare workers. Our results advocate against the routine indication of blood cultures upon admission to the Internal Medicine Ward of patients with COVID-19 pneumonia. We suggest that blood cultures could only be useful in case of clinical deterioration or suspected hospital-acquired infection.