The organism causing biliary duct obstruction?
High-Yield Explanation
Hepatobiliary ParasitismCommon in Southern China Biliary tract is infested by adult helminths or their ovaCauses:Trematodes (Liver or biliary flukes): Most CommonClonorchis sinensisOpisthorchis viverrini or O. felineusFasciola hepaticaNematode (Ascaris lumbricoides by intraductal migration of adult worm)