Copyright
©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
Clustering cases of Chlamydia psittaci pneumonia mimicking COVID-19 pneumonia
Wei Zhao, Lei He, Xing-Zhi Xie, Xuan Liao, De-Jun Tong, Shang-Jie Wu, Jun Liu
Wei Zhao, Xuan Liao, Jun Liu, Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
Wei Zhao, Jun Liu, Clinical Research Center for Medical Imaging in Hunan Province, Changsha 410011, Hunan Province, China
Lei He, Department of Radiology, The First People’s Hospital of Yueyang, Yueyang 410005, Hunan Province, China
Xing-Zhi Xie, Department of Radiology, Hunan Chest Hospital, Changsha 410013, Hunan Province, China
De-Jun Tong, Hospital Infection Control Center, The Second Xiangya Hospital, Changsha 410011, Hunan Province, China
Shang-Jie Wu, Pulmonary and Critical Care Medicine, The Second Xiangya Hospital, Changsha 410011, Hunan Province, China
Author contributions: Zhao W, He L, Xie X, Liao X, Tong D, Wu S and Liu J designed and performed the research; Zhao W analyzed the data; Zhao W and Liu J wrote the manuscript; all authors provided input on the final version of the manuscript.
Supported by the National Natural Science Foundation of China, No. 82102157; Hunan Provincial Natural Science Foundation of China, No. 2021JJ40895; the Science and Technology Innovation Program of Hunan Province, No. 2020SK53423; and the Clinical Research Center For Medical Imaging in Hunan Province, No. 2020SK4001.
Institutional review board statement: This retrospective study was approved by our Medical Ethical Committee (Approved No. 2020024), which waived the requirement for patients’ informed consent.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
http://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Jun Liu, MD, Professor, Department of Radiology, The Second Xiangya Hospital, Central South University, No. 139 Middle Remin Road, Changsha 410011, Hunan Province, China. junliu123@csu.edu.cn
Received: July 18, 2021
Peer-review started: July 18, 2021
First decision: October 11, 2021
Revised: October 11, 2021
Accepted: November 14, 2021
Article in press: November 14, 2021
Published online: December 26, 2021
BACKGROUND
The onset symptoms of people infected by Chlamydia psittaci can mimic the coronavirus disease 2019 (COVID-19). However, the differences in laboratory tests and imaging features between psittacosis and COVID-19 remain unknown.
AIM
To better understand the two diseases and then make an early diagnosis and treatment.
METHODS
Six patients from two institutions confirmed as psittacosis by high-throughput genetic testing and 31 patients confirmed as COVID-19 were retrospectively included. The epidemiology, clinical characteristics, laboratory tests and computed tomography (CT) imaging features were collected and compared between the two groups. The follow-up CT imaging findings of patients with psittacosis were also investigated.
RESULTS
The white blood cell count (WBC), neutrophil count and calcium were more likely to be decreased in patients with COVID-19 but were increased in patients with psittacosis (all P = 0.000). Lymphocyte count and platelet count were higher in patients with psittacosis than in those with COVID-19 (P = 0.044, P = 0.035, respectively). Lesions in patients with psittacosis were more likely to be unilateral (P = 0.001), involve fewer lung lobes (P = 0.006) and have pleural effusions (P = 0.002). Vascular enlargement was more common in patients with COVID-19 (P = 0.003). Consolidation in lung CT images was absorbed in all 6 patients.
CONCLUSION
Psittacosis has the potential for human-to-human transmission. Patients with psittacosis present increased WBC count and neutrophil count and have specific CT imaging findings, including unilateral distribution, less involvement of lung lobes and pleural effusions, which might help us to differentiate it from COVID-19.
Core Tip: In patients with coronavirus disease 2019 (COVID-19) the white blood cell count, neutrophil count and calcium were more likely to be decreased. Lymphocyte count and platelet count were higher in patients with psittacosis than those with COVID-19. Lesions in patients with psittacosis were more likely to be unilateral and involve less lung lobes and have pleural effusions.
