Current status and challenges in the diagnosis and treatment of psittacosis

Psittacosis is a zoonotic infectious disease caused by the obligate intracellular Gram-negative bacterium Chlamydia psittaci. Despite over a century of research, its global burden remains underestimated owing to non-specific symptoms, poor clinical recognition, and limited diagnostic capacity. This review synthesizes epidemiological evidence from 1879 to 2024, outlining transmission routes, clinical manifestations, diagnostic approaches, and therapeutic strategies, with a focus on advances in molecular diagnostics and the management of high-risk populations and complications. Surveillance data document recurrent outbreaks across Europe, North America, and Asia, with a notable increase in reported cases in China and Europe since 2020. The disease spectrum spans from atypical pneumonia to life-threatening systemic complications, including neurological, cardiac, and pregnancy-related involvement. Conventional methods, such as culture and serology, are constrained by biosafety requirements and cross-reactivity, while polymerase chain reaction, metagenomic next-generation sequencing, and targeted next-generation sequencing provide superior sensitivity but face the challenges of cost and standardization. Tetracyclines remain the mainstay of therapy, macrolides are recommended for pregnant women and children, and newer tetracycline derivatives show promise in severe or refractory cases. Psittacosis should be recognized as a systemic disease of both clinical and public health importance. Future efforts must prioritize standardizing molecular diagnostic workflows, validating novel antimicrobials in clinical practice, and incorporating psittacosis surveillance into public health systems while raising awareness, broadening diagnostic access, and optimizing therapeutic strategies to enable early detection, precision treatment, and effective control.