This study was performed to observe intestinal pathology in early infection by Centrocestus armatus. The flukes were in the lowermost part of the intervillous space of the duodenum and jejunum from 1 day to 7 days postinfection (PI). The stroma of villi around the young fluke was edematous and infiltrated by inflammatory cells such as lymphocytes, plasma cells and eosinophils. The crypt became mildly hyperplastic and villi were moderately atrophied at 4 days PI. The intestinal lesion produced was confined to the areas around the fluke. The pathologic findings were not significantly different between 1,000 and 5,000 metacercariae infection groups. It is suggested that the lesion should be produced by mechanical destruction of the fluke on the enteroepithelial cells.
