Schistosomiasis

schistosoma is distinct from other trematoda

• trematode中schistosomaは他のtrematodeと異なる特徴を持つ

schistosoma	other trematode
transmitted to human by percutaneous invasion of cercariae	transmitted to human by oral ingestion of metacercariae
male and female separated 雌雄別体	hermaphrodite雌雄同体
does not require 2nd intermediate host (no metacercariae stage)	requires 2nd intermediate host

Schistosoma japonicum

• Katsurada Fujiro found 26 May 1904 from a cat in Yamanashi（水腫腸満）
• Fujinami Kan found 30 May 1904 from a murder victim in Katayama, Hiroshima（片山病）
• found ova in 1904 in Saga（奇病）

• YouTube: Japanese schistosomiasis

pathogenesis

• ova produced by female adult within portal vein reach urinary bladder or genital tract and generate inflammation, followed by necrosis of tissue and perforation to intestine, resulted in extracorporeal distribution of ova via stool
• inflammation is exclusively due to ova
• adult pairs do not cause disease per se