Context and objectives
Bluetongue is a non-contagious infectious disease transmitted by biting midges (Culicoides species). The main vector is Culicoides imicola but other species belong the Culicoides obsoletus complex. The disease causes high mortality in sheep, whilst cattle are host but rarely show symptoms for the serotypes found in the Mediterrenean basin. The midges are very small and are suspected to spread over long distances by wind. This hypothesis has mainly been tested qualitatively and not quantitatively with the exception of Bishop (2001) and Alba et al (2004).
The objectives of the projects were twofold. The first objective was to determine the distribution of the possible vectors based on modelling. The aim was to contrast several modelling techniques as well as to determine what the minimum sampling size necessary for modelling should be.
The second objective was to characterise the possible spread of the vector by wind on a quantitative basis.
Expected scientific results
The wind trajectories show a high correlation with the different stages in the epidemics in Greece and Bulgaria. For each of the three years, we could find that based on the different serotypes of bluetongue, underlying wind patterns might explain the evolution of the epidemics.