Abstract: Chlamydia psittaci infection is a globally distributed zoonotic respiratory disease characterized by diverse and nonspecific clinical manifestations and is therefore frequently misdiagnosed as community-acquired pneumonia. Early and accurate diagnosis is crucial for controlling disease transmission and improving patient outcomes. However, conventional etiological diagnostic methods, including serological antibody assays, are limited by low sensitivity and long turnaround times. Metagenomic next-generation sequencing (mNGS), as a rapid and highly sensitive tool for pathogen detection, has demonstrated notable advantages in the diagnosis of psittacosis, particularly in patients with severe disease. By rapidly identifying the causative pathogen, mNGS provides an effective new strategy for the early clinical diagnosis and treatment of C. psittaci infection. Nevertheless, the widespread clinical implementation of mNGS continues to face several challenges, including insufficient standardization of sample pretreatment procedures.Based on a review of relevant literature from China and other countries, this article summarizes the clinical application scenarios, performance advantages, and clinical value of mNGS in the early diagnosis of C. psittaci infection and discusses the current challenges and future directions of this technology. This review aims to provide a theoretical basis for the prevention and control of C. psittaci infection and to promote the appropriate application and continuous optimization of mNGS in clinical practice.

Key words: Metagenomic next-generation sequencing, Psittacosis, Community-acquired pneumonia, Early diagnosis