Comparison of Clinical and Chest CT Characteristics of Adult Patients with COVID-19 and Mycoplasma Pneumonia

Background: Early differential diagnosis of coronavirus disease 2019 (COVID-19) and Mycoplasma Pneumonia (MP) are hampered by non-specific symptoms, the lack of rapid responding laboratory measures and the presence of family aggregation. Chest computed tomography (CT) plays a significant role to detect the distribution, density and morphology of lesions caused by either COVID-19 or MP. Objectives: To compare the symptoms, laboratory parameters, and chest CT results of adults with COVID-19 and MP and to assess the use of these findings in the differential diagnosis of these diseases. Patients and Methods: The initial clinical manifestations, laboratory results, and chest CT findings of 45 adult patients with COVID-19 (COVID-19 group) and 55 adult patients with MP (MP group) were reviewed retrospectively. All of the patients were diagnosed in the public hospitals in the epidemic area from 20 January to 28 February 2020. Results: Muscle ache and fatigue were more frequently present in the COVID-19 group (P = 0.009 and 0.029, respectively). Increased procalcitonin levels were more common in the MP group (P = 0.001). The chest CT results indicated that bilateral lung involvement, ground glass opacities, "crazy-paving" patterns, and air bronchogram signs were more common in the COVID-19 group (P < 0.001 for all), respectively. However, single lobe involvement, pulmonary consolidations, lobular central nodules, generalized bronchial wall thickening with luminal stenosis, and bronchial mucus impaction were more common in the MP group (P < 0.001 for all). Receiver operating characteristic analysis of a model established using CT parameters indicated a good or excellent performance in distinguishing COVID-19 from MP. Conclusion: COVID-19 and MP have similar clinical manifestations and laboratory results in early stage. However, the chest CT findings are valuable in the differential diagnosis of these two diseases, particularly in patients from COVID-19 epidemic areas.