1. Department of Internal Medicine, University of Gezira, Gezira, Sudan.
2. Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, Omdurman Islamic University, Khartoum, Sudan.
3. Sudan Medical Specialization Board, Sudan
4. Department of Medicine, Faculty of Medicine, University of Gezira, Sudan
5. Faculty of Medicine, Gezira University, sudan
6. Department of Medicine, Sheikh khalifa Hospital, Fujairah, United Arab Emirates
7. Department of Medicine, Sheikh khalifa Hospital, United Arab Emirates
8. Department of Medicine, Alarbaeen hospital, Omdurman, Sudan.
9. Department of Medicine, Alqasmi hospital, United Arab Emirates