Short report: Molecular genetic characterization of an unusually severe case of hydatid disease in Alaska caused by the cervid strain of Echinococcus granulosus

Abstract. Distinct Echinococcus granulosus life cycle patterns have been described in North America: domestic and sylvatic. Gene sequences of the sylvatic E. granulosus indicate that it represents a separate variant. Case-based data have suggested that the course of sylvatic disease is less severe t...

Full description

Bibliographic Details
Main Authors: Donald P. Mcmanus, Lihua Zhang, Louisa J. Castrodale, Thanh Hoa Le, Mark Pearson, David Blair
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2002
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.514.9843
http://www.ajtmh.org/content/67/3/296.full.pdf
Description
Summary:Abstract. Distinct Echinococcus granulosus life cycle patterns have been described in North America: domestic and sylvatic. Gene sequences of the sylvatic E. granulosus indicate that it represents a separate variant. Case-based data have suggested that the course of sylvatic disease is less severe than that of domestic disease, which led to the recommendation to treat cystic echinococcosis patients in the Arctic by careful medical management rather than by aggressive surgery. We recently reported the first two documented E. granulosus human cases in Alaska, with accompanying severe sequelae. Here we describe the results of molecular genetic analysis of the cyst material of one of the subjects that supported identification of the parasite as the sylvatic (cervid) strain and not the domestic (common sheep strain), which was initially thought to be implicated in these unusually severe Alaskan cases. Echinococcosis is a zoonotic infection caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). Two distinct types of Echinococci granu-losus life cycle patterns have been described in northern North America and Eurasia: domestic (pastoral) and syl-vatic.1 The former involves dogs as definitive hosts and do-mestic ungulates, mainly sheep, as intermediate ones. The