1. Nigeria Field Epidemiology and Laboratory Training Programme, Abuja, Nigeria
2. Department of Community Medicine, Ahmadu Bello University Zaria, Kaduna State, Nigeria
3. Department of Community Medicine, Alex Ekwueme Federal University Teaching Hospital, Abakaliki, Ebonyi State, Nigeria
4. Department of Epidemiology and Medical statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Nigeria