Pleural reaction, with or without pleural effusion or pneumothorax, can occur. Examination of sputum, which is often gelatinous, purulent, and bloody, will reveal the diagnostic operculated eggs of Paragonimus . Fine-needle aspiration of pulmonary lesions also yields diagnostic eggs. Paragonimiasis may resemble pulmonary tuberculosis both clinically and radiographically. The diagnosis of paragonimiasis should be considered for patients from endemic areas with compatible clinical presentations.
Serologic tests are available.
Praziquantel, given on an investigational basis, is an effective treatment of paragonimiasis. Humans become infected with C. sinensis, a parasite of freshwater fish, by eating raw or undercooked fish containing encysted metacercariae. Larvae, liberated by trypsin in the duodenum, migrate to the common bile duct and then to the distal biliary tree. There they mature into adult worms, which may persist for more than 20 years. Less commonly, adult worms are found in the gallbladder and pancreatic ducts.