1. University of Nairobi, P.O. Box 2209-00202, KNH, Nairobi, Kenya
2. Department of Surgery, University of Nairobi, P.O. Box 30197-00100, G.P.O. Nairobi, Kenya
3. ENT Department, Kenyatta National Hospital (KNH), University of Nairobi, P.O. Box 20723-00202, Nairobi, Kenya
4. Department of Pediatrics and Child Health, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya