Clinical Characteristics Of Chlamydia Psittaci Pneumonia And Risk Factor Analysis Of Severe Patients:A Retrospective Observational Study

Objective: We aimed to explore the clinical features,laboratory examination,imaging features,and severe risk predictors of Chlamydia psittaci pneumonia to identify the disease early and improve prognoses.Methods: We retrospectively analyzed the clinical data of 39 Chlamydia psittaci pneumonia patients diagnosed by next-generation sequencing and 39 non-psittacosis community-acquired pneumonia patients in the Third Xiangya Hospital of Central South University from December 2018 to April 2021.We prospectively collected part of the residual medical serum to detect Th1-related cytokines.We used R software for statistical analysis.Results: Compared with the non-psittacosis community-acquired pneumonia group,the symptoms of the common Chlamydia psittaci pneumonia group were more severe,with a longer duration of hyperthermia;most had dyspnea,accompanied by extrapulmonary symptoms such as fatigue,muscle soreness,and diarrhea.Alanine aminotransferase,aspartate aminotransferase,lactate dehydrogenase,Creactive protein,and procalcitonin increased significantly,whereas hemoglobin and albumin decreased significantly.The primary lung imaging features were consolidation and exudation,and nodules and cavities were rare.The aforementioned changes of the severe Chlamydia psittaci pneumonia group were more serious,myoglobin significantly increased,and the lesion spread to a larger area of the lung.In addition,the TH1 cell-related factor interferon-γ elevated in the Chlamydia psittaci pneumonia group.Conclusion: Extrapulmonary symptoms such as fatigue,muscle soreness,decreased hemoglobin,decreased albumin and increased liver enzymes are diagnostic predictors and risk factors of Chlamydia psittaci pneumonia.A fast respiratory rate,decreased hemoglobin,increased lactate dehydrogenase,significant involvement of multiple lobes,a high Sequential Organ Failure score,and a high Acute Physiological and Chronic Health score are diagnostic predictors and risk factors of severe Chlamydia psittaci pneumonia.The increase of interferon-γ may be related to the aggravation of the disease.