Rodo, X. Universitat de Barcelona, 93-4111438
Pascual, M. Center of Marine Biotechnology, University of Maryland, 410 - 234 8896
CHOLERA DYNAMICS AND RAINFALL VARIABILITY: AN ON-OFF RELATIONSHIP DRIVEN BY ENSO?
The role of climatic and environmental variables in cholera dynamics has become an important current issue motivated in part by growing concerns over the potential effects of global climate change. The discovery of an aquatic reservoir of Vibrio cholerae has also highlighted the potential significance of environmental factors to disease incidence. To date, however, only weak associations between cholera incidence and environmental variables have been obtained with standard statistical analyses (such as linear-lag correlation). One possible explanation for such low associations is that the relationship between variables is discontinuous as a consequence of thresholds in environmental effects. We examine this possibility for the relationship of cholera to rainfall in Bangladesh where the disease is endemic. We apply a recently developed method for detecting/identifying scale-dependent correlations, which describes how correlation coefficients vary as a function of the particular window of time examined. Results indicate that the relationship of cholera dynamics to rainfall is discontinuous, with time intervals during which the two variables are completely de-coupled alternating with those during which rainfall negatively affects disease incidence. The timing of these changes in rainfall influence appears related to ENSO. This result supports a role of ENSO on cholera dynamics.
Day: Thursday, Feb. 4
Time: 09:15 - 09:30am
Location: Sweeney Center