Clinical characteristics of Chlamydia psittaci pneumonia: a single-center, retrospective study over 5 years

Psittacosis pneumonia is not uncommon, and it can progress to severe illness or even death. Identifying the clinical characteristics of Chlamydia psittaci (C. psittaci ) pneumonia and its risk factors were the aim of improving decision-making regarding diagnosis and treatment. According to the guidelines for CAP, 59 patients with C. psittaci pneumonia were divided into a non-severe pneumonia group and a severe pneumonia group, and their clinical characteristics and the differences were analyzed and compared. The incidence of consciousness disorders is higher(P = 0.020), and the time from onset to diagnosis is longer (8 days vs. 14 days, P = 0.002), it is more prone to myocardial injury, kidney injury, hypoalbuminemia, coagulation abnormalities, and venous thrombosis (P < 0.05) in the severe group, while fatigue is more common in the non-severe group (P = 0.022). On laboratory indicators, the severe pneumonia group had a significantly longer prothrombin time (P = 0.007), higher WBC and neutrophil percentages and lower lymphocyte count and percentages, higher lactate dehydrogenase and D-dimer values (all P < 0.001). After adjustment for sex and age, logistic regression analysis identified myocardial injury as an independent risk factor for severe C. psittaci pneumonia (OR, 124.3, [95%CI, 4.25 ~ 3633.24]; P = 0.005). Impaired consciousness indicates severe illness and myocardial injury is an independent risk factor for severe C. psittaci pneumonia.