Community-acquired and hospital-acquired respiratory tract infection and bloodstream infection in patients hospitalized with COVID-19 pneumonia

Søgaard, Kirstine K.; Baettig, Veronika; Osthoff, Michael; Marsch, Stephan; Leuzinger, Karoline; Schweitzer, Michael; Meier, Julian; Bassetti, Stefano; Bingisser, Roland; Nickel, Christian H.; Khanna, Nina; Tschudin-Sutter, Sarah; Weisser, Maja; Battegay, Manuel; Hirsch, Hans H.; Pargger, Hans; Siegemund, Martin; Egli, Adrian

OBJECTIVES: SARS-CoV-2 may cause acute lung injury, and secondary infections are thus relevant complications in patients with COVID-19 pneumonia. However, detailed information on community- and hospital-acquired infections among patients with COVID-19 pneumonia is scarce. METHODS: We identified 220 SARS-CoV-2-positive patients hospitalized at the University Hospital Basel, Switzerland (between 25 February and 31 May 2020). We excluded patients who declined the general consent (n = 12), patients without clinical evidence of pneumonia (n = 29), and patients hospitalized for < 24 h (n = 17). We evaluated the frequency of community- and hospital-acquired infections using respiratory and blood culture materials with antigen, culture-based, and molecular diagnostics. For ICU patients, all clinical and microbial findings were re-evaluated interdisciplinary (intensive care, infectious disease, and clinical microbiology), and agreement reached to classify patients with infections. RESULTS: In the final cohort of 162 hospitalized patients (median age 64.4 years (IQR, 50.4–74.2); 61.1% male), 41 (25.3%) patients were admitted to the intensive care unit, 34/41 (82.9%) required mechanical ventilation, and 17 (10.5%) of all hospitalized patients died. In total, 31 infections were diagnosed including five viral co-infections, 24 bacterial infections, and three fungal infections (ventilator-associated pneumonia, n = 5; tracheobronchitis, n = 13; pneumonia, n = 1; and bloodstream infection, n = 6). Median time to respiratory tract infection was 12.5 days (IQR, 8–18) and time to bloodstream infection 14 days (IQR, 6–30). Hospital-acquired bacterial and fungal infections were more frequent among ICU patients than other patients (36.6% vs. 1.7%). Antibiotic or antifungal treatment was administered in 71 (43.8%) patients. CONCLUSIONS: Community-acquired viral and bacterial infections were rare among COVID-19 pneumonia patients. By contrast, hospital-acquired bacterial or fungal infections were frequently complicating the course among ICU patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40560-021-00526-y.