Abstract
BACKGROUND: We aimed to describe the difference between Chlamydia psittaci pneumonia group and non C. psittaci bacterial pneumonia group in community acquired pneumonia in this single-center clinical study. METHODS: We collected the data of 35 patients with C. psittaci pneumonia cases and 46 patients with non C. psittaci bacterial pneumonia cases diagnosed with metagenomic next-generation sequencing assays from February 2019 to December 2021 in Huaihua First People's Hospital in China. RESULTS: In the C. psittaci pneumonia group, 35 patients (100%) had a chance of exposure to poultry or birds, and their body temperature was greater than or equal to 39.0°C. The other common symptoms were a slow pulse (68.6%), cough (65.7%), expectoration (54.3%), chills (51.4%) and a shortness of breath (37.1%). Laboratory tests showed that >90% of the cases had markedly elevated infection indicators, and 97.1% of the cases had markedly declined calcium. The most common imaging finding was patchy shadows (94.3%), pleural effusion (68.6%), bilateral in 54.3% (n = 19) and unilateral in 45.7% (n = 16) participants, and 51.4% (n = 18) of cases met the criteria for severe pneumonia. In the non C. psittaci bacterial pneumonia group, 18 patients (39.1%) had a chance of exposure to poultry or birds, and 11 patients (23.9%) body temperature was greater than or equal to 39.0°C. Laboratory tests showed that >67% of cases had a mildly elevated infection indicators, and mildly declined serum albumin. CONCLUSION: The following characteristics are more likely to help distinguish C. psittaci pneumonia from non C. psittaci bacterial pneumonia. Including had a chance of exposure to poultry or birds, high fever, exhibit chills, expectoration, relatively slow pulse, and progress into severe pneumonia. Percentage of neutrophils, C-reactive protein, procalcitonin, lactate dehydrogenase, and myoglobin levels are higher. Blood calcium and corrected calcium are lower. Chest CT showed pleural effusion, pericardial effusion, and mediastinal lymphadenopathy.