An observational study of DDT house spraying in a rural area of Thailand.

The study investigated factors affecting public co-operation in DDT house spraying which is the most important malaria control measure in Thailand. A spraying round in a rural village in an eastern province was observed by two field workers disguised as members of the DDT spraying team. Emphasis was placed on the operational practices of spraying teams and their interactions with the villagers whose houses were to sprayed with insecticides. Villagers' unco-operative attitude to their perception of insecticides as a danger to the health of children, pregnant women and domestic animals, and unsightliness caused by whitish DDT deposits on the house walls. To some extent, lack of knowledge or disbelief in the benefit of DDT house spraying also precipitated non-co-operation. The effects of these inhibiting factors varied with villagers' socioeconomic status. More importantly, the study revealed defects in the management and supervision of the spraying operation as possible causes of low coverage of DDT house spray. Lack of health education efforts in the conduct of the spraying operation and the failures of spraymen to develop good relations with the community contributed further to the villagers' limited co-operation. The success of insecticide house spraying as a malaria control measure depends on the community as well as the malaria workers.