Mondher Bouden^1,2, Bernard Moulin^1,2 and Pierre Gosselin^2,3,4

¹Department of Computer Sciences and Software Engineering, Laval University, Quebec, G1V 0A6, Canada

²Centre for Research in Geomatics, Laval University, Quebec, G1V 0A6, Canada

³Institut national de santé publique du Québec (INSPQ), 945 avenue Wolfe, Quebec, G1V 5B3, Canada

⁴Centre hospitalier universitaire de Québec (CHUQ), 2705, boulevard Laurier, Quebec, G1V 4G2, Canada

An Open Access article. International Journal of Health Geographics 2008,
7:35.

 

Abstract

Background

Since 1999, the expansion of the West Nile virus (WNV) epizooty has
led public health authorities to build and operate surveillance systems
in North America. These systems are very useful to collect data, but
cannot be used to forecast the probable spread of the virus in coming
years. Such forecasts, if proven reliable, would permit preventive
measures to be put into place at the appropriate level of expected risk
and at the appropriate time. It is within this context that the
Multi-Agent GeoSimulation approach has been selected to develop a
system that simulates the interactions of populations of mosquitoes and
birds over space and time in relation to the spread and transmission of
WNV. This simulation takes place in a virtual mapping environment
representing a large administrative territory (e.g. province, state)
and carried out under various climate scenarios in order to simulate
the effects of vector control measures such as larviciding at scales of
1/20 000 or smaller.

Results

After setting some hypotheses, a conceptual model and system
architecture were developed to describe the population dynamics and
interactions of mosquitoes (genus Culex) and American crows,
which were chosen as the main actors in the simulation. Based on a
mathematical compartment model used to simulate the population
dynamics, an operational prototype was developed for the Southern part
of Quebec (Canada). The system allows users to modify the parameters of
the model, to select various climate and larviciding scenarios, to
visualize on a digital map the progression (on a weekly or daily basis)
of the infection in and around the crows’ roosts and to generate graphs
showing the evolution of the populations. The basic units for
visualisation are municipalities.

Conclusion

In all likelihood this system might be used to support short term
decision-making related to WNV vector control measures, including the
use of larvicides, according to climatic scenarios. Once fully
calibrated in several real-life contexts, this promising approach opens
the door to the study and management of other zoonotic diseases such as
Lyme disease.