1. Department of Immunology and Molecular Biology, Tropical Medicine Research Institute, National Centre for Research, Khartoum, Sudan
2. Faculty of Medicine, University of Khartoum, Khartoum, Sudan
3. Ed-Damazin Hospital, Blue Nile State Ministry of Health, Ed-Damazin, Sudan
4. School of Biomedical Sciences, Middlesex University, London, UK
5. Department of Microbiology, Faculty of Medicine, Blue Nile University, Ad-Damazīn, Sudan