Professor Angela McLean, Director of the Institute for Emergent Infections of Humans

Abstract: Emerging infections are more than just a current biological fashion. The bitter ongoing experience of AIDS and the looming threat of pandemic influenza teach us that the control of emerging infectious diseases is a problem we have not yet solved. Emerging infections are defined as infections that are newly discovered, newly detected or increasing in their spread. One subset, those infections that have recently spread into humans, is called “the novel emerging infections”.

I will describe interdisciplinary work from The Institute for Emergent Infections of Humans that addresses a central question in the study of novel emerging infections. That question is “when new kinds of pathogens evolve within single infected people what are the consequences for the wider community?” This is a key question because a new variant of a pathogen that grows well inside one person may grow poorly in other people so that infections are subject to constantly shifting selection pressures. The question thus concerns a process in which evolution (within-host adaptation) and ecology (between-host transmission) are inextricably intertwined and operate on identical timescales so must be considered simultaneously.