Am. J. Trop. Med. Hyg., 72(3), 2005, pp. 289-290
Copyright © 2005 by The American Society of Tropical Medicine and Hygiene
SHORT REPORT: INADEQUACY OF YAKS AS HOSTS FOR THE SHEEP DOG STRAIN OF ECHINOCOCCUS GRANULOSUS OR FOR E. MULTILOCULARIS
DAVID D. HEATH,
LI HUA ZHANG, AND
DONALD P. MCMANUS
Wallaceville Animal Research Centre, AgResearch Limited, Upper Hutt, New Zealand; Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and Nutrition, The Queensland Institute of Medical Research and the University of Queensland, Brisbane, Queensland, Australia
ABSTRACT
Hydatid disease (echinococcosis) has a two-host cycle involving the domestic dog and grazing animals. Humans are also infected by the dog. Both unilocular (Echinococcus granulosus in yaks, sheep, and goats) and multilocular (alveolar) (E. multilocularis in hares and rodents) hydatids are common in western Sichuan in the Peoples Republic of China. Humans and dogs are equally infected with both species. Many yaks (Bos grunniens) were found with multilocular cysts that visually were deemed to be E. multilocularis. However, a histologic and molecular study showed that they were actually E. granulosus. No infective cysts were found in 125 necropsied yaks. We conclude that the yak is an inadequate and dead-end host for the sheep dog (G1) strain of Echinococcus granulosus and also for E. multilocularis.
Received March 11, 2004.
Accepted for publication July 7, 2004.
Financial support: Work in the Brisbane Laboratory is supported by grants from the National Health and Medical Research Council of Australia and the Wellcome Trust.
Authors addresses: David D. Heath, Wallaceville Animal Research Centre, AgResearch Limited, PO Box 40063, Upper Hutt, New Zealand. Li Hua Zhang and Donald P. McManus, Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health & Nutrition, The Queensland Institute of Medical Research and University of Queensland, 300 Herston Road, Brisbane, Queensland 4029, Australia, Telephone: 61-7-3362 0401, Fax: 61-7-3362 0104, E-mail: donM{at}qimr.edu.au.
Copyright © 2005 by the American Society of Tropical Medicine and Hygiene.