Diarrheal Disease Control by Improved Human Excreta Disposal

Abstract

THE EFFECT of fly control on the reduction of diarrheal disease has been demonstrated twice (1, 2). In south Georgia, Lindsay, Stewart, and Watt (2) observed that the prevalence of AShigella infections was reduced during fly control activities. As long as flies were easy to control with DDT and other insecticides, an effective diarrheal disease control procedure was available, but the development of insecticide-resistant flies necessitated a closer examination of the fly's role in the transmission of diarrheal disease in the hope of finding another control procedure. The exclusion of flies from their source of human enteric pathogens should prevent fly transmission of shigellosis. An experiment was therefore designed to measure the effect of excluding flies from contact with human excrement in an area where they had previously had ready access to such excrement. Flush toilets, watercarried sewage, and sewage treatment would have been the most effective method, but for the purposes of this study a cheap and easily effected alternative was necessary. An adaptation of the bored-hole latrine was used. This consisted of a hole 8 feet deep and 16 inches in diameter, covered with a concrete slab 4 feet square, with an aluminum riser, seat, and lid. The old privy structure was moved over the slab; if there had been no privy, the householder built a simple structure. (Details of design and construction are given on pp. 926-927.) This privy rehabilitation program was conducted in Boston, Ga. (1950 population, 1,035). Boston had been included in an early fly control study (2). Until fly resistance made their use ineffective, DDT, dieldrin, and chlordane had beeni used there as residual sprays and DDT, as a space spray.