Chapter six, “The Struggle Against Hookworm Disease,” examines the early campaigns of the Rockefeller Foundation to reduce transmission of the widespread helminthic infection. Launched in the southern United States and then extended southward in the western hemisphere and into the eastern hemisphere, the anti-hookworm campaigns became the very first global health initiative. Although the campaigns utilized chemical therapies to reduce the intestinal worm load, their primary focus was on changing defecation habits, to encourage better sanitation. The campaigns failed to meet their goals, underscoring the limitations of mass drug treatment and the difficulties of changing entrenched defecation practices and the use of human waste as fertilizer.