The study took place between September 2000 and June 2001 in Khon Kaen province, in northeast Thailand. Khon Kaen consists of 25 districts and 31 large urban municipalities. The provincial population was 1,733,434 in 2002. The main ethnic group in Khon Kaen is the Esaan Thai (subgroup Laos-Wieng). Two locations in Khon Kaen were selected for this study, Baan Toom an urban community in the Khon Kaen Municipality (population of 376,915) and Baan Moon Nark a rural village in Khok Pho Chai district (population of 25,890).