In 2001, a study in urban Khon Kaen showed that DHF was ranked at 9 out of 13 diseases, coming after amphetamine addiction, diabetes mellitus, joint pains, accidents, back pain, leptospirosis, liver cancer and cold (J.H. Bryan, unpublished data). The perception of severity and susceptibility of DHF is significant during an outbreak when people were strongly motivated to undertake control activities at home. However, DHF is not new, people have been living with it for many years and believe that DHF is curable, and health services are reliable. Most participants felt control over the threat, and this reduces their perception of its severity and their susceptibility.