Study on Metagonimus yokogawai (Katsurada, 1912) in Korea V. Intestinal Pathology in Experimentally Infected Albino Rats

Abstract

Metagonimus yokogawai is the most frequent and prevalent species of the heterophyid trematodes in most areas of South-east Asia. Also in Korea, endemic foci of human infection with this fluke have been reported in various parts of South Kyongsang Do (Yeo et Seo, 1971; Loh et Kang, 1971), South Cholla Do(Soh et al., 1976; Chai et al., 1977 and Soh ct Ahn, 1978) and Cheju Do (kang et al., 1964). The prevalence rates in the inhabitants were reported to be 30-60 per cent by egg detection method. Because of the high infection rates of the inhabitants in endemic area of Korea, attentions tend to recently be aid to this minute intestinal fluke. The normal habitat of M. yokogawai is intestinal tract, especially the small intestine of human or animals. Diarrhea and/or abdominal pain has been known as the most frequent clinical complaint both in natural (Yokogawa, 1913; Koga, 1938 and Seo et al., 1971) and experimental(Koga, 1938 and Komiya et al.,1958) human cases. However, few papers have contributed to the satisfactory making out of the genesis of such symptoms and few have been available in the description of pathologic changes of the intestine, except for those of Taki(1936), Koga(1938) and Cho et al. (1978). Koga(1938) reported transient catarrh in light infection and severe catarrh sometimes with bloody mucous diarrhea in heavy infection cases of cats or dogs. But he could not observe any invasion of worms to submucosa or blood vessels. Cho et al. (1978) also observed intestinal changes in cats by experimental infection each with 80,000 Metacercariae of M. yokogawai and found mucosal edema with changed rugae pattern, lining epithelial cell necrosis, small round cell infiltration (especially the eosinophils, lymphocytes and plasma cells) etc. According to them, many worms were found from the slits of intestinal crypts with oral sucker facing the base of the crypts, but there was no evidence of worm invasion to deeper level.