Surveillance of food and waterborne diseases in Thailand, 1979-1984

National surveillance of foodborne diseases in Thailand has revealed an increasing incidence of from 29/100,000 population in 1979 to 74/100,000 in 1984. A total of 158,482 cases and 241 deaths were reported during this 6 year period. In each year, foodborne diseases occurred regularly in April-June. The highest mean annual reported rates were from the North-eastern region, followed by the Central region and the Northern region. Because of inadequate investigations, only 7% (10,567) of the total cases had known specific aetiology. Of these 10,567 cases, the majority (7788, 73%) were caused by micro-organisms which included bacteria (46%), parasites (12%), and viruses (15%), the remaining (2779, 27%) were caused by poisonous plants (19%), animals (1%), and chemicals (7%). In recent years surveillance has increasingly served as a means to control the outbreak. However, due to many limitations, the surveillance data presented here probably do not represent an accurate picture of the whole problem. Two very important factors identified are under-reporting and inadequate case and outbreak investigations.