The Jacob Marschak Interdisciplinary Colloquium on Mathematics in the Behavioral Sciences at UCLA

Young Research Library Conference Room 23167 | April 30, 2015 at 3-4:30 pm


Climate Forcing and Infectious Disease Dynamics in Changing Human Landscapes

Speaker: Mercedes Pascual, Professor of Ecology and Evolution at the University of Chicago and External Faculty at the Santa Fe Institute
Host: James Lloyd-Smith, Associate Professor of Ecology and Evolutionary Biology, UCLA

Many water-borne and vector-borne infections, including cholera and malaria, exhibit pronounced changes in the size of seasonal epidemics from year-to-year. They also exhibit longer term changes in the form of decadal trends. Although the biology of the transmission systems of these pathogens implies a sensitivity to climate variables, the role of climate variability and climate change in their temporal patterns has been the subject of protracted debate. The central challenge I will address has been to elucidate the drivers of trends and cycles in the context of the nonlinear population dynamics of the disease and of concurrent changes in other factors, such as drug resistance, economic development, and intervention measures. This talk presents insights from case studies on both cholera and malaria: from the rural environments of the highlands of East Africa and the semi-deserts of Northwest India, to the urban setting of the megacity of Dhaka, Bangladesh. Dynamical approaches are illustrated that rely on long retrospective records and mathematical models of transmission. A clear role of climate forcing is demonstrated despite other aspects of change. This role of climate is particularly important in regions of high seasonality and low transmission, found for malaria at the edge of persistence and its spatial distribution. Simple dichotomies do not apply to the question of whether climate matters. I close with some implications of our findings for the future of climate-sensitive diseases.

Dr. Pascual is a theoretical ecologist interested in the population dynamics of infectious diseases, their response to changing environments, and their interplay with pathogen diversity. She also studies the structure and dynamics of the large ecological networks of species interactions in ecosystems known as food webs. Dr. Pascual received her Ph.D. degree from the joint program of the Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology. She was awarded a U.S. Department of Energy Alexander Hollaender Distinguished Postdoctoral Fellowship for studies at Princeton University and a Centennial Fellowship in the area of Global and Complex Systems by the James S. McDonnell Foundation. She is a fellow of the American Association for the Advancement of Science, an investigator of the Howards Hughes Medical Institute, and a recipient of the Robert H. MacArthur award of the Ecological Society of America. Photo courtesy ICDDR, B.