1. Department of Pediatrics, University of Chieti, Chieti, Italy
2. Department of Pediatrics and Child Health, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania
3. Department of Internal Medicine, Hindu Mandal Hospital, Dar es Salaam, Tanzania
4. Department of Biostatistics and Epidemiology, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania
5. Department of Ophthalmology, Muhimbili National Hospital, Dar es Salaam, Tanzania