Dengue, dengue haemorrhagic fever (DHF) and dengue shock syndrome remain important public health problems in Thailand with approximately 100 cases of DHF per 100,000 population occurring in 2003 (Division of Epidemiology, 2004). The first DHF outbreak was recognised in Bangkok and the surrounding areas in 1958 and the incidence of DHF has increased cycli- cally ever since. In 1978, the Ministry of Public Health established the dengue prevention and control programs, carried out nationwide by integrating the control program into the Primary Health Care system (Chunsuttiwat and Wasakarawa, 1994; Wangroongsarb, 1998). In 1999, the King project for dengue prevention and control program were introduced in Thailand. The program aims to increase knowledge of DHF disease and prevention as well as encouraging people to carry out the larval control in households