Evidence from countries that continued using DDT showed that correct and timely use of indoor spraying can reduce malaria transmission by up to 90%. In the past, India was able to use DDT effectively to substantially cut the number of malaria cases and deaths.
It also was effective for insect control in crop and livestock production, institutions, homes, and gardens. DDT's quick success as a pesticide and broad use in the United States and other countries led to the development of resistance by many insect pest species.