1. Department of Public Health and Occupational Medicine, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-Shi, Mie 514-8507, Japan
2. Foreign Relation Division, Cabinet of the Ministry of Health, Rue Simeuang, Ban Thatkhao, Sisattanack District, Vientiane Capital, Laos
3. Lao Tropical and Public Health Institute, Ministry of Health, Samsenthai Road, Ban Kaognot, Sisattanack District, Vientiane Capital, Laos
4. Department of Epidemiology and Preventive Medicine, Ehime University Graduate School of Medicine, 454 Shitsukawa, Toon-shi, Ehime 791-0295, Japan
5. Faculty of Child Education, Suzuka University, 663-222 Koriyama-Cho, Suzuka-Shi, Mie 510-0298, Japan
6. Epidemiology Centre for Disease Control and Prevention, Mie University Hospital, 2-174 Edobashi, Tsu-Shi, Mie 514-8507, Japan