Affiliation: | a Department of Veterinary Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA b Department of Preventive Medicine, Faculty of Veterinary Science, University of Khartoum, Khartoum, Sudan c Department of Medicine, Pharmacology and Toxicology, Faculty of Veterinary Science, University of Khartoum, Khartoum, Sudan d Department of Pathology, Faculty of Veterinary Science, University of Khartoum, Khartoum, Sudan e Department of Medical Helminthology, London School of Hygiene and Tropical Medicine, University of London, London, UK |