Comparing viral, bacterial and co-infections in community- acquired pneumonia, a retrospective cohort study

Science and Research

BACKGROUND: Despite substantial rates of viral aetiology of community-acquired pneumonia (CAP) empirical antibiotic therapy is regularly administered. This study compares the clinical presentation, antibiotic use, and outcomes of CAP patients based on the identified causative pathogens. METHODS: Immunocompetent CAP patients from the international, multicentre prospective CAPNETZ cohort study from 2007-2017 with available multiplex PCR testing for bacterial / viral pathogens from sputum were included. Patients were divided into four groups, based on the detection of bacterial pathogens, viral pathogens, bacterial/viral co-infection and no pathogen detected. Differences were analysed using multivariate linear regression. RESULTS: Patients with bacterial CAP were significantly younger (median age 60 years; aOR 0.96 [0.94-0.98]) and reported less smoking (aOR 0.98 [0.97-1.0]). Higher CRB-65 score was associated with bacterial CAP (aOR 1.69 [1.1-2.58]). bacterial CAP showed higher 180-day mortality (aOR 3.59 [1.09-11.8]) and viral CAP had higher 30-day mortality (aOR 15.79 [1.04-238.75]) in comparison with other groups. Upon admission, the four groups could not be discriminated based on clinical presentation and showed no differences in CAP-related complications, length of stay and application / duration of antibiotic treatment (98.4% received antibiotics). CONCLUSIONS: A pathogen-centred treatment algorithm in CAP patients is required to avoid unnecessary antibiotic therapies, side effects and to optimize patient outcomes and long-term morbidity.