Clinical Features, Treatment, and Outcome of Psittacosis Pneumonia: A Multicenter Study

Abstract Background We aimed to describe psittacosis pneumonia and risk factors for developing severe pneumonia in this multicenter clinical study. Methods We collected the data of psittacosis pneumonia cases diagnosed with metagenomic next-generation sequencing (mNGS) assay from April 2018 to April 2022 in 15 tertiary hospitals in China. Results A total of 122 patients were enrolled; 50.0% had a definite history of bird exposure. In 81.2% of cases, onset happened in autumn or winter. The common symptoms were fever (99.2%), cough (63.1%), fatigue (52.5%), shortness of breath (50.0%), chills (37.7%), central nervous system symptoms (36.9%), myalgia (29.5%), and gastrointestinal tract symptoms (15.6%). Laboratory tests showed that >70% of cases had elevated C-reactive protein, procalcitonin, erythrocyte sedimentation rate, D-dimer, lactate dehydrogenase, and aspartate aminotransferase, and >50% had hyponatremia and hypoproteinemia. The most common imaging finding was consolidation (71.3%), and 42.6% of cases met the criteria for severe pneumonia. Age >65 years and male sex were the risk factors for severe pneumonia. The effective proportion of patients treated with tetracyclines was higher than that of fluoroquinolones (66/69 [95.7%] vs 18/58 [31.0%]; P < .001), and the median defervescence time was shorter. After medication adjustment when the diagnosis was clarified, 119 of 122 (97.5%) patients were finally cured and the other 3 (2.5%) died. Conclusions Psittacosis pneumonia has a high rate of severe disease. Proven diagnosis could be rapidly confirmed by mNGS. Tetracycline therapy had a rapid effect and a high cure rate.