1. Department of Medicine, College of Medicine, University of Nigeria, Enugu Campus, Enugu 400241, Nigeria
2. Department of Medicine, College of Health Sciences, University of Ilorin, Ilorin 240213, Nigeria
3. Department of Internal Medicine, Federal Teaching Hospital, Ebonyi State, Abakaliki 480281, Nigeria
4. Department of Medicine, University of Nigeria Teaching Hospital, Ituku Ozalla, Enugu 400228, Nigeria
5. Medical Division, Nigerian Ports Authority PLC, Lagos 101251, Nigeria