Affiliation: | (1) Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, P.O. Box 21452, U.I. Post Office, Ibadan, Nigeria;(2) Department of Veterinary Public Health and Animal Production, Faculty of Veterinary Medicine, Usmanu Danfodiyo University, P.M.B. 2346 Sokoto, Nigeria;(3) Department of Veterinary Tropical Disease, Faculty of Veterinary Sciences, University of Pretoria, Pretoria, South Africa;(4) National Institute for Public Health and the Environment (RIVM), 3720 BA Bilthoven, The Netherlands |