The work environment often contained standing water, sometimes knee-deep, and the larvae were capable of surviving several weeks in the water, allowing them to infect many of the workers. In 1897, it was established that the skin was the principal avenue of infection and the biological life cycle of the hookworm was clarified. Eradication programmes
In 1899, American zoologist Charles Wardell Stiles identified progressive pernicious anemia seen in the southern United States as being caused by the hookworm A. duodenale. Testing in the 1900s revealed very heavy infestations in school-age children. In Puerto Rico, Dr. Bailey K. Ashford, a US Army physician, organized and conducted a parasite treatment campaign, which cured approximately 300,000 people (one-third of the Puerto Rican population) and reduced the death rate from this anemia by 90 percent during the years 1903–04. On October 26, 1909, the Rockefeller Sanitary Commission for the Eradication of Hookworm Disease was organized as a result of a gift of US$1 million from John D. Rockefeller, Sr. The five-year program was a remarkable success and a great contribution to the United States public health, instilling public education, medication, field work and modern government health departments in eleven southern states. The hookworm exhibit was a prominent part of the 1910 Mississippi state fair. The commission found that an average of 40% of school-aged children were infected with hookworm. Areas with higher levels of hookworm infection prior to the eradication program experienced greater increases in school enrollment, attendance, and literacy after the intervention.
School-based programs are extremely cost-effective as schools already have an available, extensive, and sustained infrastructure with a skilled workforce that has a close relationship with the community. With little training from a local health system, teachers can easily administer the drugs which often cost less than US$0.50 per child per year.Recently, many people have begun to question if the school-based programs are necessarily the most effective approach. An important concern with school-based programs is that they often do not reach children who do not attend school, thus ignoring a large number of at-risk children. A 2008 study by Massa et al. continued the debate regarding school-based programs. They examined the effects of community-directed treatments versus school-based treatments in the Tanga Region of Tanzania. A major conclusion was that the mean infection intensity of hookworm was significantly lower in the villages employing the community-directed treatment approach than the school-based approach. The community-directed treatment model used in this specific study allowed villagers to take control of the childs treatment by having villagers select their own community drug distributors to administer the antihelminthic drugs. Additionally, villagers organized and implemented their own methods for distributing the drugs to all children. The positive results associated with this new model highlight the need for large-scale community involvement in deworming campaigns. Public health education
Many mass deworming programs also combine their efforts with a public health education. These health education programs often stress important preventative techniques such as: washing your hands before eating, and staying away from water/areas contaminated by human feces.