Secondary Infections in Patients with Severe COVID-19

In critically ill patients with severe COVID-19, nosocomial infections must be differentiated from COVID-19–induced inflammation. Two European studies address the characteristics of such secondary infections.

Researchers in Spain retrospectively studied 140 critically ill patients with COVID-19, 41% of whom experienced bacterial or fungal infections (or both; 91 episodes in total) a median of 9 days after intensive care unit (ICU) admission. Patients with secondary infections were older (63 vs. 61 years) and had higher APACHE II scores (15 vs. 13) and longer ICU stays (20 vs. 11 days) than uninfected patients. Nosocomial infections consisted of primary (31%) and catheter-related (25%) bloodstream infections, pneumonia (23%), tracheobronchitis (10%), and urinary tract infection (8%). Pathogens included Gram-positive bacteria (55%), Gram-negative bacteria (30%), and fungi (15%). Among infected patients, 60% developed septic shock; among all patients, 36% died in the ICU. Severe acute respiratory distress syndrome at admission, nosocomial infection, and APACHE II scores all were significantly associated with mortality.

In the second study, a case-control analysis encompassing six ICUs in France, investigators assessed 235 patients with COVID-19 compared with 235 critically ill patients having other diagnoses; patients were matched for admission category, age, sex, SOFA score, and intubation within the first two ICU days. Patients with COVID-19 had significantly higher likelihood of bloodstream infections (15% vs. 3%) and antibiotic use in the first 2 days (79% vs. 68%) as well as longer ICU stays (9 vs. 6 days) and higher mortality (36% vs. 16%).