Studies On Parasitic Helminths Of Korea 5.Survey On Intestinal Trematodes Of House Rats.

A study was carried out to evaluate the house rats in southern Korea as reservoir host of intestinal trematodes, in 13 different areas: 7 in inland and 6 in brackish-water zones, during the period from August 1980 to August 1981. A total of 170 house rats was captured; 101 rats from inland and 69 from brackish-water zones. They consisted of 129 Rattus norvegicus, 22 R. rattus rufescens, and 19 unidentified. The infection status of the rats were as follows: 1. Total 29 rats (17.1%) were infected by one or more kinds of intestinal trematodes; 27 from inland and 2 from brackish-water zones by areas. Rats in inland were more heavily infected. 2. The intestinal trematodes collected from rats were identified as Echinostoma hortense, E. cinetorchis, Plagiorchis muris, Fibricola seoulensis, Clonorchis sinensis and Metagonimus yokogawai. 3. As a reservoir host, the rats were very important in Echinostoma hortense and E. cinetorchis infection. Rats infected with these trematodes were found widely in southern Korea, and its infection rates were the highest among the discriminated flukes. 4. In this study, no rats were found to be infected with Heterophyes and Pygidiopsis even in endemic areas. The negligible importance of rats as reservoir host of these heterophyid should be reevaluated in the future.