[1] HENRY M JACKSON FDN,ROCKVILLE,MD 20850
[2] JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,BALTIMORE,MD 21205
[3] ROYAL THAI MINIST PUBL HLTH,DEPT COMMUNICABLE DIS CONTROL,CHIANG MAI 50200,THAILAND
[4] CHIANG MAI UNIV,RES INST HLT SCI,CHIANG MAI 50200,THAILAND