[Internal seminar] Dengue as a complex system: case studies in Delhi, Bangkok and “artifical cities”
By Eric Daudé, Somsakun Maneerat, Alexandre Cebeillac and Renaud Misselin
Thursday 11 December 2014, 03:00pm – 06:00pm
CSH conference room
Places, social’s functioning and practices influence aspects of health in population groups. Using geographic data of past or ongoing epidemics, spatial analysis methods help to identify socio-environmental processes affecting geographic heterogeneity in health indicators. With the help of Geographic Information Systems (GIS), it is possible to perform territorial diagnostics of health indicators and to follow their progression in a monitoring perspective. When data are partially available or even the processes on health phenomena and population future health statuses are still to be tested and predicted, researchers use models, especially geosimulation. With agent-based models, different populations of agents interact in heterogeneous environments and lead to specific dynamics, according to the scenarios/parameters tested by the researchers. In the same agent-based model different kinds of agents can coexist: human beings, mosquitoes, viruses and spatial units. The transmission of this vector-borne disease involves the mosquito Aedes aegypti as vector, the humans as hosts, the four serotypes of virus (DEN-1, DEN-2, DEN-3, and DEN-4) as pathogenic agent and environments that can either constrain or favor the mosquito life and/or the virus transmission cycle. Each of these elements is dynamic and contributes to the epidemic risk. The fluctuations in mosquito populations, the mobility of people, the introduction of a new virus strain and meteorological variations are in interaction and may have an impact on the emergence of the disease in a given place. Local context and past dynamics as well act as important elements of future dynamics. Thus, geosimulation enables investigating the relative weight of the different factors according to multiple scenarios. Furthermore, based on initial conditions which depict observed situations, different possible evolutions of the system can be inferred.