Background: Few data are available on the impact of bacterial pulmonary co-infection (RespCoBact) during COVID-19 (CovRespCoBact). The aim of this study was to compare the prognosis of patients admitted to an ICU for influenza pneumonia and for SARS-CoV-2 pneumonia with and without RespCoBact.

Methods: This was a multicentre (n = 11) observational study using the Outcomerea© database. Since 2008, all patients admitted with influenza pneumonia or SARS-CoV-2 pneumonia and discharged before 30 June 2021 were included. Risk factors for day-60 death and for ventilator-associated-pneumonia (VAP) in patients with influenza pneumonia or SARS-CoV-2 pneumonia with or without RespCoBact were determined.

Results: Of the 1349 patients included, 157 were admitted for influenza and 1192 for SARS-CoV-2. Compared with the influenza patients, those with SARS-CoV-2 had lower severity scores, were more often under high-flow nasal cannula, were less often under invasive mechanical ventilation, and had less RespCoBact (8.2% for SARS-CoV-2 versus 24.8% for influenza). Day-60 death was significantly higher in patients with SARS-CoV-2 pneumonia with no increased risk of mortality with RespCoBact. Patients with influenza pneumonia and those with SARS-CoV-2 pneumonia had no increased risk of VAP with RespCoBact.

Conclusions: SARS-CoV-2 pneumonia was associated with an increased risk of mortality compared with Influenza pneumonia. Bacterial pulmonary co-infections on admission were not associated with patient survival rates nor with an increased risk of VAP.