Infectious events in patients with severe COVID-19: results of a cohort of patients with high prevalence of underlying immune defect

BACKGROUND: Empirical antibiotic has been considered in severe COVID-19 although little data are available regarding concomitant infections. This study aims to assess the frequency of infections, community and hospital-acquired infections, and risk factors for infections and mortality during severe COVID-19. METHODS: Retrospective single-center study including consecutive patients admitted to the intensive care unit (ICU) for severe COVID-19. Competing-risk analyses were used to assess cumulative risk of infections. Time-dependent Cox and fine and gray models were used to assess risk factors for infections and mortality. Propensity score matching was performed to estimate the effect of dexamethasone. RESULTS: We included 100 patients including 34 patients with underlying malignancies or organ transplantation. First infectious event was bacterial for 35 patients, and fungal for one. Cumulative incidence of infectious events was 27% [18–35] at 10 ICU-days. Prevalence of community-acquired infections was 7% [2.8–13.9]. Incidence density of hospital-acquired infections was 125 [91–200] events per 1000 ICU-days. Risk factors independently associated with hospital-acquired infections included MV. Patient’s severity and underlying malignancy were associated with mortality. Dexamethasone was associated with increased infections (36% [20–53] vs. 12% [4–20] cumulative incidence at day-10; p = 0.01). After matching, dexamethasone was associated with hospital-acquired infections (35% [18–52] vs. 13% [1–25] at 10 days, respectively, p = 0.03), except in the subset of patients requiring MV, and had no influence on mortality. CONCLUSIONS: In this population of COVID-19 patients with high prevalence of underlying immune defect, a high risk of infections was noted. MV and use of steroids were independently associated with infection rate. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13613-021-00873-x.