Distribution of eggs and the host response in chickens infected with Austrobilharzia variglandis (Trematoda).
Segments of cleared intestines from chickens infected with the marine (avian) schistosome Austrobilharzia variglandis showed eggs clustered around branches of blood vessels on each side of the intestine. Most of the eggs, as seen in sections, were found in the vessels or lamina propria of the mucosa. A comparison of distribution of eggs relative to the location of adults within the intestinal vessels suggested that eggs were deposited in mucosal vessels by ovigerous females. Only immature eggs were found in blood vessels while those in or near crypts were mature. This was correlated with movement of eggs from blood vessels to the intestinal lumen. The accumulation of numerous eggs, edema, cellular infiltration, and hyperplasia of smooth muscle contributed to a substantial increase in thickness of the intestinal wall. Granulomatous responses to the presence of eggs were observed from day 12 to 18 wk PI. They ranged in nature from dense accumulations of mononuclear cells, to the appearance of fully developed granulomas, and included phagocytosis by giant cells and the Hoeppli phenomenon.
D000818:Animals; D002645:Chickens / Q000469:parasitology; D005260:Female; D006099:Granuloma / Q000469:parasitology; D007422:Intestines / Q000469:parasitology; D010063:Ovum; D011201:Poultry Diseases / Q000469:parasitology; D012552:Schistosomiasis / Q000469:parasitology* / Q000662:veterinary