Conclusions: Promises and Pitfalls
Fulfilling the mandate of World Health Assembly resolution 54.19 will require the regular treatment of hundreds of millions of children over decades. The obstacles in this undertaking are formidable, and success will depend on the ability of countries to identify or create reliable and sustained infrastructures for this purpose. A focus on using preexisting school systems may be key to achieving this goal. The treatment of schoolchildren for A. lumbricoides, T. trichiura, and schistosome infections achieves large externalities that reduce infection in other vulnerable age groups. However, the different epidemiology of hookworm raises concerns about the risks to preschool children and women of reproductive age who remain untreated. Providing regular treatment to these populations appears to be a less cost-effective option, largely because of the absence of a preexisting infrastructure. This situation presents a strong argument for developing a hookworm vaccine that could be used to protect these vulnerable groups. It has yet to be seen whether the emergence of BZA drug resistance is a genuine concern that could derail global deworming efforts in much the same way that resistance to DDT and chloroquine has affected the ambitions for global malaria control. It is possible that the specific dynamics of helminth populations will provide sufficient genetic flow to maintain susceptibility in much the same way that insecticides remain the effective staple of global agribusiness. Until new technologies become available, anthelmintic chemotherapy for school-age children remains the most practical and substantive means to control STH and schistosome infections in the developing world.
