Data gathering procedure

Access to the villages was granted by the district government officers. Village headmen were contacted and provided brief information regarding the study, including a date for a future meeting. During the meeting with the village headman, all essential information related to the study was provided, and the researchers asked to obtain a list of village members who met the study criteria. Researchers returned to the villages again after receiving the list of villagers who met the study criteria. An appointment was made 3 days in advance of data collection, including requesting participants fasted (nothing per oral (NPO)) for 12 h. prior to blood specimen collection. On the day of data collection, all participants who met the study criteria were provided the complete information related to the study in both Thai and the local language with the help of village health volunteers fluent in both Thai and the local languages. After verifying that they met the criteria, the participants were asked to complete the informed consent form before a 5 mL blood specimen was collect, followed by a 15-min interview to complete the questionnaire. Blood specimens were properly stored and transferred to the Mae Fah Laung Medical Laboratory Center for laboratory testing on the same day.