1. Department of Epidemiology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
2. Department of Zoology, Faculty of Sciences, University of Khartoum, Khartoum, Sudan
3. National University Research Institute, National University, Khartoum, Sudan
4. Department of Parasitology and Medical Entomology, Faculty of Medicine and Health Science, University of Kordofan, Elobeid, Sudan