1. Department of Internal Medicine Faculty of Medicine Chulalongkorn University Bangkok, Thailand
2. Department of Preventive and Social Medicine Faculty of Medicine Chulalongkorn University Bangkok, Thailand
3. Department of International Health Johns Hopkins Bloomberg School of Public Health Baltimore, Maryland, USA
4. Department of Pathology Faculty of Medicine Chulalongkorn University Bangkok, Thailand
5. Department of Biochemistry Faculty of Medicine Chulalongkorn University Bangkok, Thailand