Research

Pigs, which thrive on cheap and abundant nutritional sources and grow quickly, are one of the most important sources of food and income for the world’s poorest populations. But pigs also serve as the reservoir for the pork tapeworm, Taenia solium. Humans develop an intestinal infestation a er consuming undercooked pork where the tapeworm has encysted, shedding thousands of eggs in their stool which are, in turn, consumed by pigs, beginning the cycle anew.

When humans consume the eggs of the pork tapeworm directly, the tapeworm leaves the gastrointestinal tract and can migrate throughout
the body. A serious condition known as neurocysticercosis develops when the parasite enters the brain leading to destruction of tissue. Millions of people living in low-income communities in Latin America, Africa, and Asia are infected and develop a range of symptoms including headaches, seizures, and strokes. In school-aged children, cognitive de cits caused by brain involvement negatively impacts academic performance. By curtailing children’s cognitive potential and reducing productivity in affected communities, T. soliumcontributes to a cycle of poverty.

Environmental contamination plays an integral role in sustaining T. solium infection. Small holder farmers depend on free-range pig raising, allowing their livestock to forage throughout the surrounding environment, and poor populations lack safeguards to keep their environment free of contamination with human stool and T. solium eggs: relying on open sewers, lacking latrines and defecating in the open, and fertilizing their crops using untreated human stool.

We have established study sites across Tibetan steppe communities in Western Sichuan, China, where poor smallholder farmers raise free-range pigs, allowing them to range throughout villages, surrounding fields, and mountain environs. Our work has shown that levels of disease in these communities are very high. Behaviors that lead to environmental contamination such as open defecation, lack of proper toilets and sewage systems, and use of untreated human stool as fertilizer on crops are widespread.

Using disease burden studies combined with behavioral and environmental surveys, we are designing, piloting, and evaluating interventions. These interventions combine pig vaccination, treatment of human tapeworm carriers, educational measures to enforce behavioral change, improved methods of sewage handling and treatment, and strategies to decrease environmental contamination with human stool.

Our close working relationship with our Chinese collaborators allows us to adapt interventions to local communities in discussion with local veterinarians, community leaders, and government authorities. We plan to design interventions around local products, encouraging the growth of local markets. We hope that clear positive improvements in human health, farm productivity, and environmental conditions will create a clear incentive for communities to continue interventions over the long term.

Our close working relationship with our Chinese collaborators allows us to adapt interventions to local communities in discussion with local veterinarians, community leaders, and government authorities. We plan to design interventions around local products, encouraging the growth of local markets. We hope that clear positive improvements in human health, farm productivity, and environmental conditions will create a clear incentive for communities to continue interventions over the long term.