Malaria in the Americas: a model of reemergence.

Malaria in the Americas is a reemerging health issue. In 1969, the World Health Organization shifted policy from malaria eradication to malaria control. With this shift, vector control (house spraying with dichlorodiphenyltrichloroethane [DDT]) was deemphasized. Since that time, house spray rates have decreased and malaria rates have increased. Using malaria data collected since 1959 by the Pan American Health Organization, this relationship was examined with an ecological regression model. Malaria control was found to be a function of policy, disease burden, and vector control (R2 = 0.75, p < 0.001). Policy must address both disease burden and vector control. Treatment of disease burden is unquestioned; however, vector control is debated. An argument for the judicious and enlightened resumption of house spraying with DDT is presented.