1. Department of Paediatrics, Aminu Kano Teaching Hospital, Kano, Nigeria
2. Department of Paediatrics, Bayero University Kano/Aminu Kano Teaching Hospital, Kano, Nigeria
3. Department of Paediatrics, University of Nebraska Medical Centre, Omaha, NE, USA
4. International Foundation Against Infectious Diseases in Nigeria, Abuja, Nigeria
5. University of Jos/Jos University Teaching Hospital, Jos, Nigeria