Background/Aims@#
Secondary infection with
influenza virus occurs in
critically ill patients and is associated with substantial
morbidity and
mortality; however, there is limited information about it in
patients with severe coronavirus disease 2019 (COVID-19). Thus, we investigated the clinical outcomes of and
risk factors for
secondary infections in
patients with severe COVID-19. @*
Methods@#This study included
patients with severe COVID-19
who were admitted to seven
hospitals in
South Korea between February 2020 to February 2021. Multivariate
logistic regression analyses were performed to assess factors associated with the
risk of
secondary infections. @*Results@#Of the 348 included
patients, 104 (29.9%) had at least one
infection. There was no statistically significant difference in the 28-day
mortality (17.3% vs. 12.3%, p = 0.214), but
in-hospital mortality was higher (29.8% vs. 15.2%, p = 0.002) in the infected group than in the non-infected group. The
risk factors for
secondary infection were a high
frailty scale (
odds ratio [OR], 1.314; 95%
confidence interval [CI], 1.123 to 1.538; p = 0.001),
steroid use (OR, 3.110; 95% CI, 1.164 to 8.309; p = 0.024), and the application of
mechanical ventilation (OR, 4.653; 95% CI, 2.533 to 8.547; p < 0.001). @*Conclusions@#
In-hospital mortality was more than doubled in
patients with severe COVID-19 and
secondary infections. A high
frailty scale, the use of
steroids and application of
mechanical ventilation were
risk factors for
secondary infection.