A case report of Paragonimus infection diagnosed by medicine thoracoscopy

This is a case report of a 38-year-old woman with recurrent pleural effusion. The patient was hospitalized twice within a six-month period. During the initial admission for pleural effusion, serological testing by ELISA revealed positive antibodies against Schistosoma japonicum and sparganum. Parasitic infection was suspected, prompting initiation of praziquantel therapy. The patient was admitted to our department again one month prior with recurrent pleural effusion. Medical thoracoscopy was performed to establish etiology, and parasite moving in a peristaltic manner were observed in the right posterior pleura near the costal angle. The parasite was identified under a microscope as Paragonimus, and Paragonimus was also detected by mNGS of pleural effusion, confirming paragonimiasis. The patient underwent repeat praziquantel therapy, with no pleural effusion recurrence observed during a four-month follow-up period. This case highlights the importance of a definitive diagnosis, with thoracoscopy and mNGS can be used as a new diagnostic idea and method to help diagnose paragonimiasis with pleural lesions.