Abstract
INTRODUCTION: Tropheryma whipplei (TW), which causes Whipple disease, has recently been associated with respiratory diseases, particularly pneumonia. To understand its role in pediatric pneumonia, this study analyzed the clinical and pathogenetic characteristics of TW in pediatric pneumonia patients. METHODS: We utilized metagenomic and targeted next-generation sequencing (mNGS/tNGS) data from 3,759 pediatric bronchoalveolar lavage fluid (BALF) samples (2023-2024). This case-control study included 103 TW-positive pediatric pneumonia patients (59 with severe pneumonia, SPTW+; 44 with mild pneumonia, MPTW+), along with 206 TW-negative pneumonia patients as controls (118 with severe pneumonia, SPTW-; 88 with mild pneumonia, MPTW-). RESULTS: Through inter-group comparisons, the results showed that TW-positive patients were younger and had lower BMIs than controls, with shorter hospital stays and milder inflammation. Severe TW-positive cases showed more localized right-lung lesions, less pleural effusion, and more bronchial involvement. Mycoplasma pneumoniae co-detection was frequent (86.4%), along with Moraxella catarrhalis, human bocavirus type 1, and rhinovirus A. DISCUSSION: TW-positive pediatric pneumonia presents with milder symptoms, suggesting that TW may act as a colonizer rather than a primary pathogen. Consequently, antimicrobial treatment specifically targeting TW may not be immediately warranted at detection. These results provide important insight for the individualized treatment of pediatric pneumonia with TW positive.