Application of geographic information technology in determining risk of eastern equine encephalomyelitis virus transmission

Geographic information system (GIS) technology and remote sensing were used to identify landscape features determining risk of eastern equine encephalomyelitis virus (EEE) transmission as defined by the abundance of Culiseta melanura (the enzootic vector) and 6 putative epidemic-epizootic vectors in Massachusetts. Landsat Thematic Mapper data combined with aerial videography data were used to generate a map of landscape elements at epidemic-epizootic foci in southeastern Massachusetts. Geographic information system technology was used to determine the proportion of landscape elements surrounding 15 human and horse case sites where abundance data were collected for Culiseta melanura, Aedes canadensis, Aedes vexans, Culex salinarius, Coquillettidia perturbans, Anopheles quadrimaculatus, and Anopheles punctipennis. The relationships between vector abundance and landscape proportions were analyzed using stepwise linear regression. Stepwise regression indicated wetlands as the most important major class element, which accounted for up to 72.5% of the observed variation in the host-seeking populations of Ae. canadensis, Ae. vexans, and Cs. melanura. Moreover, stepwise linear regression demonstrated deciduous wetlands to be the specific wetland category contributing to the major class models. This approach of utilizing GIS technology and remote sensing in combination with street mapping can be employed to identify deciduous wetlands in neighborhoods at risk for EEE transmission and to plan more efficient schedules of pesticide applications targeting adults.