Clinical Characteristics of Chlamydia psittaci Infection Diagnosed by Metagenomic Next-Generation Sequencing: A Retrospective Multi-Center Study in Fujian, China

Kaixiong Liu,1– 3,* Luling Wu,4,5,* Gongping Chen,1– 3,* Dunhuan Zeng,1– 3 Qiwei Zhong,6 Li Luo,1,2 Bin Song,7 Xiuhong Ying,1,2 Fayu Ni,8 Lifang Yu,8 Liyu Xu,9 Xin Lin,9 Xiaoyan Chen,10 Xin Zou,11 Jianhong Xiao,7 Yuekai Hu5,12,13 1Department of Respiratory and Critical Care medicine, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Fujian Medical University, Fuzhou, People’s Republic of China; 3Institute of Respiratory Disease, Fujian Medical University, Fuzhou, People’s Republic of China; 4Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China; 5Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China; 6Department of Respiratory and Critical Care Medicine, Minnan Hospital, the First Affiliated Hospital of Fujian Medical University, Quau zhou, People’s Republic of China; 7Department of Respiratory and Critical Care Medicine, Mindong Hospital Affiliated to Fujian Medical University, Ningde, People’s Republic of China; 8Department of Respiratory, Fuqing General Hospital Affiliated to Fujian Medical University, Fuzhou, People’s Republic of China; 9Department of Respiratory and Critical Care Medicine, Fuzhou First Hospital of Fujian Medical University, Fuzhou, People’s Republic of China; 10Department of Emergency Medicine, Zhangzhou Affiliated Hospital of Fujian Medical University, Zhangzhou, People’s Republic of China; 11Department of Respiratory and Critical Care Medicine, LongYan First Hospital Affiliated to Fujian Medical University, Longyan, People’s Republic of China; 12Department of Infectious Diseases, First Affiliated Hospital of Fujian Medical University, Fuzhou, People’s Republic of China; 13Department of Infectious Diseases, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yuekai Hu; Jianhong Xiao, Email huyuekai@fudan.edu.cn; xjh1030@sina.comObjective: This study aimed to describe and compare the epidemiological, demographic, clinical, laboratory and radiological characteristics as well as the complications, treatments, and outcomes of these patients.Methods: We retrospectively investigated clinical data of patients with C. psittaci infection (psittacosis) in eight Grade IIIA hospitals of Fujian. Metagenomic next-generation sequencing (mNGS) was used identify C. psittaci in clinical samples of all included patients.Results: A total of 74 patients (39 severe/35 non-severe) was diagnosed with psittacosis, 25 (33.8%) of whom had history of poultry exposure. Common symptoms included high fever (98% [37/74]), fatigue (52.7% [39/74]), and dyspnea (51.4% [38/74]). Common manifestations in imaging included consolidation (89.2%), pleural effusion (77.0%), and air bronchogram (66.2%). Common complications included acute respiratory distress syndrome (55.4% [41/74]), type I respiratory failure (52.7% [39/74]), acute liver injury (41.9% [31/74]), and secondary infection (27.0% [20/74]). The in-hospital mortality rate was 8.11% (6/74).Conclusion: C. psittaci infection is represents an underestimated cause of CAP. For SCAP patients with poultry and bird contact history, specimens were encouraged to be sended for mNGS test in time. C. psittaci infection can lead to severe, multiple system involvement, and several complications. mNGS facilitate timely diagnosis of C. psittaci infection.Keywords: Chlamydia psittaci, metagenomic next-generation sequencing, community-acquired pneumonia, bronchoalveolar lavage fluid