Differential diagnosis of community-acquired pneumonia and lung damage in respiratory viral infections, including COVID-19

With the development of the coronavirus pandemic and its decline, bacterial pathogens will again play a significant role in the epidemiology of community-acquired pneumonia (CAP). Numerous studies have already examined clinical, laboratory, and instrumental indicators that allow differential diagnosis between viral infection and bacterial pneumonia. The role of conventional (e.g., C-reactive protein, procalcitonin, leukocytes) and novel laboratory markers (e.g., MxA1 protein, progranulin, copeptin) was revealed. Differences in lung CT and ultrasound findings were noted. The aim of this publication is to present data on the differential diagnosis between pulmonary involvement in viral infections, including COVID-19 (COronaVIrus Disease 2019), and bacterial CAP. Conclusion. Despite numerous studies, distinguishing bacterial CAP from viral lung injury, including that associated with COVID-19 infection, without microbiologic testing is a challenging task that requires a combined assessment of clinical data, laboratory data, and modern imaging studies. Obviously, express testing will be of particular interest in this case.