Paragonimus and paragonimiasis in Korea

The lung fluke, Paragonimus, and lung fluke disease, were reviewed, especially on the works performed in Korea. Among 43 species of Paragonimus recorded in the world literature, P. westermani, P. pulmonalis, and P. iloktsuenensis are known to distribute in Korea. Biological studies on P. westermani have revealed that its snail intermediate host is Semisulcospira spp. and major second intermediate hosts are crabs such as Eriocheir japonicus and E. sinensis or crayfish such as Cambaroides similis and C. dauricus. The final hosts other than man are dogs, cats, pigs, and wild animals. Paragonimiasis has been known to distribute widely over the south Korea, however, the prevalence among people and intermediate hosts is gradually decreasing in recent years. In Korean people, the lung fluke have caused pulmonary infections in a great many of cases but as well extrapulmonary ones including cerebral, spinal, subcutaneous, hepatic, splenic, abdominal, urinary, gynecologic, and other types. The definite diagnosis of paragonimiasis can be executed by the recovery of eggs from sputum or feces of patients, however, immunological methods such as intradermal test, complement-fixation test, precipitin reactions, immunofluorescent techniques, enzyme-linked immunosorbent assay (ELISA) are greatly helpful for egg-negative or extrapulmonary cases. Various drugs have been introduced for the treatment of paragonimiasis, and among them, bithionol, niclofolan and praziquantel have shown high therapeutic efficacy. The most recommendable one is considered praziquantel. For control of this disease, mass chemotherapy of patients seems to be the most efficient and feasible measure.