Comparison of Clinical, Laboratory and Radiological Characteristics Between COVID-19 and Adenovirus Pneumonia: A Retrospective Study

BACKGROUND: The pandemic of coronavirus disease 2019 (COVID-19) has become a global public health problem. It is important for clinical physicians to differentiate COVID-19 from other respiratory infectious diseases caused by viruses, such as human adenovirus. SUBJECTS AND METHODS: This was a retrospective observational study. We analyzed and compared the clinical manifestations, laboratory findings and radiological features of two independent cohorts of patients diagnosed with either COVID-19 (n=36) or adenovirus pneumonia (n=18). RESULTS: COVID-19 did not show a preference in males or females, whereas 94.4% of patients with adenovirus pneumonia were males. Fever and cough were common in both COVID-19 and adenovirus pneumonia. But the median maximal body temperature of the adenovirus pneumonia cohort was significantly higher than in COVID-19 (P<0.001). Furthermore, 77.8% of patients with adenovirus pneumonia had a productive cough versus only 13.9% of COVID-19 patients (P<0.001). Compared with adenovirus pneumonia, constitutional symptoms were less common in COVID-19, including headache (16.7% vs 38.9%, P=0.072), sore throat (8.3% vs 27.8%, P=0.058), myalgia (8.3% vs 61.1%, P<0.001) and diarrhea (8.3% vs 44.4%, P=0.002). Furthermore, patients with COVID-19 were less likely to develop respiratory failure (8.3% vs 83.3%, P<0.001) and showed less prominent laboratory abnormalities, including lymphocytopenia (61.1% vs 88.9%, P=0.035), thrombocytopenia (2.8% vs 61.1%, P<0.001), elevated procalcitonin (2.8% vs 77.8%, P<0.001) and elevated C-reactive protein (36.1% vs 100%, P<0.001). Besides, a higher percentage of patients with adenovirus pneumonia showed elevated transaminase, myocardial enzymes, creatinine and D-dimer compared with COVID-19 patients. On chest CT, the COVID-19 cohort was characterized by peripherally distributed ground-glass opacity and patchy shadowing, while the adenovirus pneumonia cohort frequently presented with consolidation and pleural effusion. CONCLUSION: There were many differences between patients diagnosed with COVID-19 and those with adenovirus pneumonia in their clinical, laboratory and radiological characteristics. Compared with adenovirus pneumonia, COVID-19 patients tended to show a lower severity of illness.