Metagenomic Next-Generation Sequencing for the Diagnosis of Trichomonas Vaginalis-Associated Empyema: a Case Report and Literature Review.

BACKGROUND

This report describes a rare case of empyema caused by Trichomonas vaginalis co-infected with Streptococcus agalactiae and Streptococcus pyogenes, aiming to explore the role of T. vaginalis in the development of empyema, its diagnostic methods, and treatment strategies.

METHODS

The patient was a 46-year-old male who presented with cough, sputum production, and shortness of breath. The diagnosis was made using chest CT, routine pleural fluid analysis, bacterial culture, and metagenomic next-generation sequencing (mNGS). Pleural fluid examination revealed numerous motile Trichomonas organisms, and bacterial culture identified Streptococcus agalactiae and Streptococcus pyogenes as the pathogens. Fur-ther mNGS confirmed these bacteria as the causative agents, with 39 Trichomonas sequences detected, including 32 sequences specific to T. vaginalis.

RESULTS

The patient received combination antimicrobial therapy and underwent chest tube drainage and thoracoscopic empyema debridement. Post-treatment, the patient's condition significantly improved. A literature review revealed that while Trichomonas tenax is a common pathogen in empyema, T. vaginalis is an extremely rare cause. T. vaginalis infection may be associated with bacterial co-infections, immunosuppression, or poor hygiene.

CONCLUSIONS

This case is the first report of T. vaginalis induced empyema, expanding the understanding of Trichomonas infections. Although such infections are rare, they should be considered in high-risk patients. Further studies are needed to investigate the infection pathways of T. vaginalis and its mechanisms of bacterial synergy in disease pathogenesis to improve clinical diagnosis and treatment strategies.