Time limitation and the role of research in the worldwide attempt to eradicate malaria.

The U.S. Congress established an intense, time-limited, worldwide malaria eradication program in 1958 and assigned operational responsibility to the U.S. Agency for International Development (and its predecessors). When the program was terminated on schedule in 1963, approximately $400 million had been consumed and malaria prevalence had greatly been reduced. Transmission began to increase thereafter. The open-ended WHO global eradication effort began in 1955 ended in 1969 and consumed approximately $15 million during the 1958-1963 period of progress, mainly provided by the United States. Intensified anti-malaria interventions continued after Congress discontinued direct support. Although malariological research was discouraged during the period of time limitation, it was embraced as the conceptual basis for the open-ended period of intervention that followed. This effort saved many lives but expended our ability to intervene against future epidemics and reduced human herd immunity. To avoid the "great gamble" inherent in any ambitious intervention against this disease, future programs should be designed to seek incremental, local antimalaria gains.