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two mothers and children


CAGED: Campylobacter Genomics and Environmental Enteric Dysfunction

Principal Investigator (PI) and Lead Institution

Dr. Arie Hendrik Havelaar, University of Florida

Collaborator Institutions and Co-PIs


Research has shown that young children who eat chicken eggs grow better and gain life-long benefits. Our research in Ethiopia tests the benefits of improved poultry production by smallholders aiming to produce more eggs for their children. We also examine the advantages of protecting their children from chicken droppings by using coops, which should further improve health and growth of the children.

Our research targets a major threat to children who encounter chicken droppings: bacteria called Campylobacter (camp-ee-low-back-ter). These bacteria increase the likelihood of a syndrome of chronic gut inflammation in children, called environmental enteric dysfunction (EED). EED plays a major role in the vicious cycle of diseases and poverty, and it may cause up to 40% of stunting worldwide. In Ethiopia, we are exploring solutions to the apparent linkages between chicken droppings, the children who contract Campylobacter, and the stunting that undermines their potential.  

Initial Study

Prior to a full trial, formative research will assess villages in eastern Ethiopia for the prevalence of stunting, of EED, and of Campylobacter in children and domestic animals. Genetic studies will indicate if 1-year old children are contracting infections predominantly from chickens. We will also test how well people adopt chicken coops and how much this practice affects chicken droppings and the presence of Campylobacter in the children’s homes. After successfully completing this formative research in year one, the CAGED study will proceed to the full trial.

Long-term Study

Over a five-year period, the CAGED study will test two hypotheses:

  • Do new practices that limit exposure to chicken droppings reduce Campylobacter in young children?
  • Does less Campylobacter in children improve their health, by reducing chronic gut inflammation and increasing their growth?

The study uses a cluster randomized controlled trial, a common technique for medical experiments, which studies people in groups that are randomly assigned to a treatment.   

The three treatments types of full, partial, or control (no treatment) will be randomly assigned to neighborhoods across the Haramaya District in Eastern Ethiopia, and families with young children will be identified. Selected families in the full treatment arm will receive 10 vaccinated chickens, mobile chicken coops, poultry feed and animal health care. These households will also receive extensive training on human nutrition and animal management. To assure that all chickens are housed properly, the neighboring families of the full treatment arm will also receive 5 chickens in mobile coops. Families in the partial treatment arm will receive the same intervention as those in the full treatment arm, except for the mobile poultry houses (their chickens will be allowed to scavenge freely). Finally, families in the control arm will be practicing traditional chicken husbandry, with scavenging chickens of traditional breeds, which commonly are kept in the home overnight.

Technical Advisory Group: This group will guide the project and assess the formative research in year one.

  • Vivek Kapur, Penn State University, Chair
  • Nick Juleff, Bill & Melinda Gates Foundation
  • Eric Fèvre, University of Liverpool, UK & ILRI, Nairobi, Kenya
  • Nigel French, Massey University, Palmerston North, New Zealand
  • Aulo Gelli, International Food Policy Research Institute, Washington DC
  • Andy Jones, University of Michigan, Ann Arbor, MI
  • Supriya Kumar, Bill & Melinda Gates Foundation
  • James Platts-Mills, University of Virginia, Charlottesville, VA

Learn More

This study is funded by the Bill & Melinda Gates Foundation as part of the Equip project.

Photo credits: S. McKune

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Feed the Future Innovation Lab for Livestock Systems

This work was funded in whole or part by the United States Agency for International Development (USAID) Bureau for Food Security under Agreement # AID-OAA-L-15-00003 as part of Feed the Future Innovation Lab for Livestock Systems. Additional funding was received from Bill & Melinda Gates Foundation. Any opinions, findings, conclusions, or recommendations expressed here are those of the authors alone.