Relative distribution of Schistosoma japonicum eggs in the intestine of man: a subject of inconsistency

Abstract

The relative distribution of Schistosoma japonicum eggs in the intestine of man is inconsistent in the literature. Some scientists believe that the adult S. japonicum worms reside mainly in the superior mesenteric vein and their eggs are deposited predominately in the small intestine, whereas others have shown that the adult worms have a predilection for inhabiting the branches of the inferior mesenteric vein and superior haemorrhoidal vein and their eggs are deposited in much higher density in the large intestine, especially in the rectum, sigmoid and descending colon, than in the small intestine. A review of the literature was made which includes the results from animal experiments as well as from human clinical and pathological studies. The author is in favour of the latter view that in man, S. japonicum eggs are deposited predominately in the large intestine and small intestine involvement is usually slight.