Demographical Distribution on the Incidence of Helicobacter pylori Infection in Jakarta: Obtaining Samples from 5 Municipalities - Syam, Ari Fahrial; Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine, University of Indonesia/Dr. Cipto Mangunkusumo General National Hospital, Jakarta (The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy, 2014)