1. Department of Pharmacology and Therapeutics, College of Medicine University of Ibadan Ibadan Nigeria
2. Department of Clinical Pharmacology University College Hospital Ibadan Nigeria
3. Department of Epidemiology and Medical Statistics, College of Medicine University of Ibadan Ibadan Nigeria
4. African Field Epidemiology Network (AFENET) Abuja Nigeria
5. Department of Research and Statistics Federal Ministry of Health Abuja Nigeria