1. Departme , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 72500 , Vietnam
2. nt of Pediatrics, Faculty of Medicine, Pham Ngoc Thach University of Medicine , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 72500 , Vietnam
3. Department of Gastroenterology, Children's Hospital 2 , Ho Chi Minh City, 14 Ly Tu Trong Str., Dist 1, 71000 , Vietnam
4. Depar , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 71500 , Vietnam
5. tment of Epidemiology, Faculty of Public Health, Pham Ngoc Thach University of Medicine , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 71500 , Vietnam
6. Pham Ngoc Thach University of Medicine , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 72500 , Vietnam
7. Department of Family Medicine, Faculty of Medicine, Pham Ngoc Thach University of Medicine , Ho Chi Minh City, 2 Duong Quang Trung Str., Dist 10, 72500 , Vietnam