Trends in malaria morbidity and mortality in Sri Lanka.

Trends since 1930 in malaria morbidity and mortality in Sri Lanka were analysed. The Malaria Control Programme, which began in 1945 with DDT spraying, was associated with a 100-fold reduction in morbidity and mortality over the following ten years, and gave way to the Malaria Eradication Programme in 1958. DDT spraying ceased in 1964 and a vivax malaria epidemic in 1968 returned to the island to 1952 morbidity levels, though with little mortality. After the discovery of DDT resistance in 1969, malathion spraying took over in 1973, and USAID-assisted control programme, involving case-detection and treatment, started in 1977. However, morbidity levels comparable to 1952 levels were observed in 1975 and 1986 when falciparum malaria morbidity levels were especially high. Mortality rates since 1960 have however remained lower than at any other previous time.