Clinical Features and Risk Factors for Rhabdomyolysis in Patients with Chlamydia psittaci Pneumonia: A Multicenter Study

Purpose: Chlamydia psittaci infection can lead to rhabdomyolysis (RM); however, systematic characterization of RM in patients with Chlamydia psittaci pneumonia has not been performed. This study analyzed the clinical characteristics of and risk factors for RM in patients with Chlamydia psittaci pneumonia. Patients and Methods: Clinical data of patients with Chlamydia psittaci pneumonia who were admitted to hospitals in Guangdong Province between January 2020 and December 2025 were retrospectively collected. Serum muscle enzyme activities at admission and factors associated with RM development were investigated. Results: Elevated creatine kinase (CK) levels were observed in 46.8% of patients, and 20.5% developed RM. Compared with the non-severe pneumonia group, the severe pneumonia group included significantly more patients with elevated CK levels and RM ( P < 0.001). Compared with patients without RM, those with RM experienced higher incidences of myalgia, dyspnea, and altered consciousness, and they had a higher Pneumonia Severity Index (PSI), a greater likelihood of acute kidney injury, and longer hospital stays; additionally, they more commonly required mechanical ventilation. Systemic inflammatory markers (such as C-reactive protein [CRP]), skeletal muscle and myocardial injury markers, D-dimer levels, and hepatic and renal dysfunction indicators were substantially escalated in patients with RM; however, their serum sodium and albumin levels were significantly lower ( P < 0.05). High PSI, elevated CRP level, dyspnea, and hyponatremia were considered independent risk factors for RM in patients with Chlamydia psittaci pneumonia. Conclusion: RM is an important complication of Chlamydia psittaci pneumonia. Early monitoring and intervention are warranted to improve the prognosis. Keywords: Chlamydia psittaci , pneumonia, rhabdomyolysis, risk factors