Parasites and Biliary stones

Billiary parasites ٤
Billiary parasites
Helminthic invasion of the human biliary tract is a prominent
medical and surgical problem especially in tropical and subtropical areas
where these parasites are endemic (Philips and Yung, 1960). Helminthic
infestation may affect the liver and/or the biliary tract either during
passage of worms through these structures or because these organs serve
as their natural habitat. The parasitic infestations affecting the biliary tract
including the nematode Ascaris lumbricoides, the trematodes
Opisthorchis viverrini and felineus, Clonorchis sinensis,
Dicrocoeliasis , and Fasciola hepatica, and the cestodes Echinococcus
granulosus and multilocularis (Carpenter,1998), also some protozoa
can cause biliary tract disease as Cryptosporidium (Mandell et al.,
2000), and Giardiasis (Tessier and Davies, 1999).
Manifestations of biliary parasitic infestations:
Parasites in the biliary tree can cause the syndrome commonly
referred to as ‘Oriental cholangiohepatitis’. Features of this syndrome
include helminthiasis, biliary stones formation, choledochal obstruction
and recurrent cholangitis. A parasite may act as a nidus for stone
formation (Yellin and Donovan, 1981).
The stones associated with ‘Oriental cholangiohepatitis’ are darkly
pigmented, soft and friable, different from gallstones seen in the Western
part of the world. However, the relation between choledocholithiasis and
parasites may be coincidental. Clinically, ‘Oriental cholangiohepatitis’
includes biliary colic, jaundice, cholecystitis and/or cholangitis
(Shulman, 1987).