Published online Dec 28, 2020. doi: 10.4329/wjr.v12.i12.289
Peer-review started: November 11, 2020
First decision: November 29, 2020
Revised: December 3, 2020
Accepted: December 8, 2020
Article in press: December 8, 2020
Published online: December 28, 2020
Processing time: 47 Days and 8.3 Hours
Influenza viruses were responsible for most adult viral pneumonia. Presently, coronavirus disease 2019 (COVID-19) has evolved into serious global pandemic. COVID-19 outbreak is expected to persist in months to come that will be synchronous with the influenza season. The management, prognosis, and protection for these two viral pneumonias differ considerably and differentiating between them has a high impact on the patient outcome. Reverse transcriptase polymerase chain reaction is highly specific but has suboptimal sensitivity. Chest computed tomography (CT) has a high sensitivity for detection of pulmonary disease manifestations and can play a key-role in diagnosing COVID-19. We reviewed 47 studies and delineated CT findings of COVID-19 and influenza pneumonia. The differences observed in the chest CT scan can be helpful in differentiation. For instance, ground glass opacities (GGOs), as the most frequent imaging finding in both diseases, can differ in the pattern of distribution. Peripheral and posterior distribution, multilobular distribution, pure or clear margin GGOs were more commonly reported in COVID-19, whereas central or peri-bronchovascular GGOs and pure consolidations were more seen in influenza A (H1N1). In review of other imaging findings, further differences were noticed. Subpleural curvilinear lines, sugar melted sign, intra-lesional vascular enlargement, reverse halo sign, and fibrotic bands were more reported in COVID-19 than H1N1, while air space nodule, tree-in-bud, bronchiectasia, pleural effusion, and cavitation were more seen in H1N1. This delineation, when combined with clinical manifestations and laboratory results may help to differentiate these two viral infections.
Core Tip: Co-incidence of coronavirus disease 2019 (COVID-19) and influenza in the influenza season can be challenging for the health system. The management, prognosis, and protection for these two viral pneumonias differ considerably. Chest computed tomography (CT) has a high sensitivity for detection of pulmonary disease manifestations and can be helpful in diagnosing COVID-19. In this review, we made a comparative study of CT findings in COVID-19 and influenza A pneumonia, as well as their clinical manifestations, by a thorough review of literature. Delineation of differences observed in the chest CT scan of COVID-19 and influenza can be helpful in differentiation.