[A case of paragonimiasis westermani diagnosed on the observation of parasitic ova in bronchial washing fluid and successfully treated with praziquantel].

A 41-year-old male visited our clinic complaining of cough and dirty hemosputum. Roentgenogram and CT scan of the chest revealed a cavitary nodule in the S1+2 of the left lung. After administration of antibiotics (CFIX, ASPC, FMOX, CLDM), the cavities were disappeared but the size of the nodule remained unchanged. Because the possibility of lung cancer could not be excluded, we underwent transbronchial brushing and bronchial lavage. Then, parasitic ova of Paragonimus westermani was detected in BALF, and an Ouchterlony's double diffusion test showed strong reaction against Paragonimus westermani antigen. The patient was successfully treated with praziquantel. Efficacy of the treatment was confirmed by a remarkable decrease of antibody titer measured by microplate-EIA.