1. Laboratory of Veterinary Epidemiology, Department of Veterinary Science, Graduate School of Life and Environmental Sciences; Osaka Prefecture University; 1-58 Rinku Orai-kita; Izumisano, Osaka; 598-8531; Japan
2. Department of Paraclinical Studies; School of Veterinary Medicine, University of Zambia; P.O. Box 32379; Lusaka; Zambia