Clinical Features of 50 Cases of Chlamydia psittaci Pneumonia Identified Through Metagenomic Next-Generation Sequencing.

Abstract

Background: Our objective was to analyze the clinical and imaging features of Chlamydia psittaci pneumonia to enhance its diagnostic accuracy.

Methods: We systematically reviewed the cases of Chlamydia psittaci diagnosed by next-generation sequencing at the Hunan University of Medicine General Hospital between March 2019 and June 2024, summarizing and analyzing their clinical characteristics and imaging features.

Results: A total of 50 cases that met the inclusion criteria were ultimately included in the study analysis. The median age of the patients was 62.96±11.08 years. Notably, 46 patients (92%) had potential exposure to birds or poultry. Forty-six patients (92%) temperature ≥39.0 °C, 37 patients (74%) had cough, 34 patients (68%) had moist rale, and 39 patients (78%) had a relatively slow pulse. Laboratory tests indicated that over 70% of patients exhibited elevated infection markers, accompanied by abnormalities in liver and renal function, electrolyte levels, and cardiac enzymes. Meanwhile, the patient's white blood cell count was normal. Chest CT (Computed Tomography) frequently revealed flaky shadows (94%), thoracic effusions (68%), and thickened pleura (54%). Bronchoscopy revealed significant bronchial mucosal hyperemia, swelling (93.478%), and reduced secretion (56.522%). A total of 44 patients (88%) showed a gradual improvement over 12 days. Forty patients (80%) were treated with doxycycline. Fifty patients were classified into two groups according to whether severe pneumonia occurred after admission. WBC (white blood cell), N% (percentage of neutrophils), NLR (Neutrophil-to-lymphocyte ratio), PLR (platelet/lymphocyte ratio), SII (platelet*Neutrophil/lymphocyte ratio), and PCT (procalcitonin) are indicators that suggest severe cases.

Conclusion: The combination of the following indicators is expected to aid in diagnosis of Chlamydia psittaci pneumonia: opportunities to come into contact with birds or poultry, high fever, relatively slow pulse, and elevated infection indicators accompanied by organ injury. Treatment with doxycycline was effective and resulted in favorable prognosis.