The epidemiology of trachoma in southern Malawi.

A population-based prevalence survey of ocular disease was conducted in the Lower Shire River Valley of Malawi in 1983. A total of 5,436 children less than 6 years of age and 1,664 persons greater than or equal to 6 years were examined. The prevalence of inflammatory trachoma peaked in the 1-2-year-old age group at 48.7% and declined rapidly with age to less than 5% by age 15. The prevalence of cicatricial trachoma was low in young children and climbed gradually with age to greater than 40% among those greater than or equal to 50 years. Risk factors for inflammatory disease in young children included low socioeconomic status of the family, long walking distance to the household's primary source of water, absence of a latrine in the family compound, and presence of trachoma among siblings. Indices of crowding practices were not associated with inflammatory disease. An apparent inverse association of facewashing and inflammatory trachoma in children did not hold up when adjusted for other risk factors.