The CDC helped lead a hugely successful campaign against the disease. The insides of thousands of homes across the South were sprayed with DDT; sources of standing water were drained or sprayed with pesticides; supplies were boosted of the drug chloroquine, which at that time was highly effective against malaria (the parasite in many parts of the world has now grown resistant to it).
Within five years of the CDC's founding, malaria was essentially wiped out in the United States.
But the agency and other organizations that led the fight, such as the Tennessee Valley Authority and the Rockefeller Foundation, only deserve partial credit. At least as big a factor as the drugs and DDT was a change in economic circumstances, as well as agricultural reforms. By the time the CDC got involved in 1946, malaria was already fading fast.
Margaret Humphreys, a history professor at Duke University and author of "Malaria: Poverty, Race and Public Health in the United States," says that one of the most important factors in the eradication of malaria was the economic policy of the New Deal.
Under the New Deal, beginning in the early 1930s farmers were paid to leave their land fallow; this forced Southern farmworkers, who were the most common victims of malaria at the time because of their constant work in the fields and their proximity to big mosquito populations, to move to towns to look for other jobs. New Deal loans to farmers, which allowed them to buy tractors and other equipment that meant less demand for labor, also helped stop the spread of the disease.
Rural, poor and sick
Malaria, particularly in the United States, is largely a rural disease. Towns and cities have a smaller mosquito population because standing water is drained to make way for development; rural areas don't often have the tax base to pay for extensive drainage.
The nation's growing prosperity after World War II also played a key role, helping to create the modern infrastructure that is now so effective against malaria. Even as simple an improvement as screens on a house's doors and windows — a rarity in the rural Southern shotgun shacks of the 1930s but increasingly common after the war — helped sound the death knell for the malaria parasite in the United States.
So what's the lesson here for Africa? Simply put, it's that the best way to fight malaria there is to fight poverty. Usually, international aid experts put it the other way — the best way to fight poverty in Africa is to fight malaria.
These statements aren't mutually exclusive, of course. Essentially, efforts put into increasing prosperity will tend to reduce malaria, and vice versa. The best approach, then, would be to do both.