This project will investigate the evolution of host-pathogen dynamics in human populations. The investigators will focus on dietary iron, which is vital for life, but also presents hazards, including its availability to pathogens as well as an individual host's own cells. Hosts have evolved multiple mechanisms to withhold iron from infectious agents, and infectious agents, such as bacteria, have evolved a diverse array of mechanisms to acquire iron from their hosts, resulting in an evolutionary "arms race" over iron. The project will advance fundamental knowledge about this "arms race" in a human population with high pathogen load, to understand how diet, iron nutrition, infection risk, and growth and development are related, and how humans may have adapted to high pathogen environments. The research findings may also inform public health efforts to address iron nutrition and deficiency. This international collaboration will include both field and laboratory training opportunities for students at the undergraduate and graduate levels, including groups under-represented in science. <br/><br/>This project evaluates the impact of iron status on immunity and infection among children in a population with high rates of iron deficiency and infectious disease. Over the course of one year, participating children will be evaluated monthly for measures of diet, growth and development, iron intake, immune function and infection. The relative importance of diets as causes of iron deficiency and anemia will be described. The prevalence of impaired cell-mediated immunity and incidence of infectious diseases will be compared across iron status groups. In this manner, this study will work toward disentangling the complex interactions between diet, growth and development, iron nutrition, immunity, and infectious disease.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.