1. Department of Surgery, Tamale Teaching Hospital, P.O. Box TL 16, Tamale, Ghana
2. Department of Microbiology, School of Medicine and Health Sciences, University for Development Studies, P.O. Box TL 1850, Tamale, Ghana
3. Department of Pathology, School of Medicine and Health Sciences, University for Development Studies, P.O. Box TL 1850, Tamale, Ghana