The study, the first of its kind in modern times, was carried out by the National School of Tropical Medicine at Baylor College of Medicine in conjunction with Alabama Center for Rural Enterprise (ACRE), a nonprofit group seeking to address the root causes of poverty. In a survey of people living in Lowndes County, an area with a long history of racial discrimination and inequality, it found that 34% tested positive for genetic traces of Necator americanus.
To control the disease, thousands of individuals were treated, decreasing prevalence to 39%. After these interventions, there were increases in school enrolment, attendance, and literacy, and those within the treated cohort had substantial gains in long-term incomes. However, because of posttreatment reinfection and widespread transmission, hookworm infection and disease continued to persist in the southern United States, especially in areas of extreme poverty. According to a study in the 1950s, rural Alabama still suffered from a high prevalence of hookworm infection in schoolchildren, with some counties having 60% infection. With improved sanitation and waste disposal infrastructure, in association with aggressive economic development in the southern United States, the prevalence of hookworm infection decreased (paper, p. 2, citations omitted).