Clinical characteristics and risk factors associated with severe community-acquired pneumonia infected by Chlamydia psittaci.

Abstract

The study aimed to describe the clinical features of psittacosis pneumonia and identify risk factors associated with severe psittacosis pneumonia. We retrospectively collected data from patients with psittacosis pneumonia, confirmed by metagenomic next-generation sequencing (mNGS) from January 2022 to June 2024 and analyzed differences between severe and non-severe groups. A total of 24 patients (eight severe/16 non-severe) were diagnosed with psittacosis, and 33.3% had severe psittacosis pneumonia. The levels of white blood cells (WBCs), neutrophils, neutrophil-to-lymphocyte ratio (NLR), hypersensitive C-reactive protein (hs-CRP), and procalcitonin (PCT) and the detection rate of fungi by mNGS were significantly higher in the severe group than in the non-severe group. The length of stay and omadacycline use were longer in patients of the severe group when compared to the non-severe group. Receiver operating characteristic (ROC) curves indicated that NLR had a better predictive value of severe conditions than PCT and hs-CRP. Patients with psittacosis pneumonia have a high rate of severe disease, and NLR may be a useful tool to promptly ascertain the severity of the disease and optimal therapies for better outcomes.

Importance: This study explores the clinical features of psittacosis pneumonia and identifies key factors that may predict the severity of the disease. By analyzing data from 24 patients diagnosed using metagenomic next-generation sequencing (mNGS), the research uncovers important differences between severe and non-severe cases. The study finds that patients with severe psittacosis pneumonia have elevated levels of white blood cells (WBCs), neutrophils, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (hs-CRP), and procalcitonin (PCT), as well as a higher detection rate of fungi. Notably, the NLR emerges as a strong predictor of severe disease, suggesting its potential as an early diagnostic tool. These findings provide valuable insights that can help healthcare providers identify high-risk patients more quickly, allowing for timely interventions and improved management of the disease. Ultimately, this research could lead to better outcomes by guiding treatment decisions and enhancing our understanding of psittacosis pneumonia.