The outbreaks of many infectious diseases display pronounced seasonal and interannual (year to year) variation. To date, investigations of the role of environmental factors including climatic ones, have not significantly progressed beyond simple correlative analyses. This project develops quantitative approaches to address the role of climate and other environmental factors in the population dynamics of infectious diseases, particularly those with temporary (short-lived) immunity and free-living infectious stages. The work focuses on cholera in its main endemic region (NE India and Bangladesh), but also other regions of Asia (Vietnam) and Africa (Mozambique). Its ultimate aim is to develop quantitative scenarios for cholera under climate change, by combining results on disease-environmental couplings with climate models.The applicability of the developed quantitative approaches to other diseases (particularly malaria and other vector borne pathogens) will be examined.
The global climate is changing. The most likely avenues for impacts on disease dynamics are through concomitant changes in the seasonal environmental variables that drive transmission, and through changes in the dominant (interannual) modes of variability (e.g. ENSO) that are observed in the current climate. Neither mechanism can be understood without a solid understanding of how climate variability has influenced disease patterns in the past. Extensive spatial and temporal cholera records provide an opportunity to address such understanding for an infectious disease remaining a public health problem around the globe, particularly in Asia but also Africa, for which the role of the environment is an important open question.
