Which species of Schistosoma primarily affects the intestines?

Schistosoma mansoni is recognized for its primary association with intestinal pathology. It is one of the major species of Schistosoma responsible for schistosomiasis, particularly in regions of Africa, the Middle East, and South America. The adult S. mansoni worms reside in the mesenteric veins surrounding the intestines, leading to the formation of eggs that can cause significant tissue damage and inflammation in the intestinal wall. This can result in gastrointestinal symptoms, including abdominal pain, diarrhea, and rectal bleeding due to the direct effects of the eggs and the immune response they trigger.

In contrast, other species such as Schistosoma haematobium primarily affect the urinary system by residing in the venous plexus of the bladder, while Schistosoma japonicum is more commonly associated with both intestinal and hepatic complications but is more specifically linked to liver pathology in addition to intestinal symptoms. Schistosoma intercalatum also affects the intestines but is less prevalent and more localized compared to S. mansoni. Thus, S. mansoni is specifically noted as the primary species impacting intestinal health in schistosomiasis.