title: Studies on the use of cobalt-60 gamma irradiation to control infectivity of Clonorchis sinensis metacercariae.
abstract: The purpose of the present study was to observe the survival and development of Clonorchis sinensis metacercariae in their final hosts after Cobalt-60 gamma irradiation of isolated metacercariae or the parasite in fish. Guinea pigs or albino rats were orally infected with irradiated metacercariae by gavage. Bioassay, fecal examination for ova, and necropsy of infected animals, were the methods used for the estimation of minimum effective dose of gamma irradiation to control infectivity of the metacercariae. Results showed that the minimum effective irradiation dose for isolated metacercariae was 0.05 kGy. The LD50 of the irradiation dose for metacercariae in fish was 0.05 kGy, and the minimum effective dose was 0.15 kGy. No significant difference in radiation susceptibility to Co-60 gamma irradiation was found among C. sinensis metacercariae in fishes collected at different localities in northern, middle or southern parts of China. The present finding suggests that irradiation of fish by 0.15 kGy could control infectivity of C. Sinensis metacercariae and thus be adopted as a control measure in preventing infections.
authors.affiliation: Institute of Parasitic Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, People's Republic of China.
authors.forename: C C
authors.initials: CC
authors.lastname: Song
authors.forename: Y F
authors.initials: YF
authors.lastname: Duan
authors.forename: G C
authors.initials: GC
authors.lastname: Shou
authors.forename: H
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002681:China; D003004:Clonorchis sinensis / Q000254:growth & development / Q000472:pathogenicity / Q000528:radiation effects*; D003037:Cobalt Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*; D005069:Evaluation Studies as Topic; D005243:Feces / Q000469:parasitology; D005399:Fishes; D005514:Food Irradiation / Q000379:methods* / Q000592:standards; D016266:Food Parasitology; D006168:Guinea Pigs; D010270:Parasite Egg Count; D011867:Radioisotope Teletherapy
chemical_list: D003037:Cobalt Radioisotopes