ABSTRACT
A health impact evaluation of the Rural Sanitation Pilot Project in Mohale's Hoek district; Lesotho; was conducted from October 1987 to September 1988. A clinic-based case-control design was used to investigate the impact of improved sanitation on diarrhoea morbidity in young children. The results indicate that under-5-year-olds from households with a latrine may experience 24 percent fewer episodes of diarrhoea than such children from households without a latrine (odds ratio = 0.76; 95 percent confidence interval; 0.58-1.01). The impact of latrines on diarrhoea was greater in those households that used more water; practised better personal hygiene; and where the mothers had a higher level of education or worked outside the home. In common with studies conducted in Malawi; Philippines; and Sri Lanka; little evidence was found that the relationship between latrine ownership and diarrhoea was confounded by socioeconomic status or environmental variables. For a sample of cases and controls; data on exposure status (presence or absence of a latrine) that were collected by interview at the clinics agreed closely with those obtained by observation during a home visit