Quantitative monitoring of Aedes albopictus in Emilia-Romagna, Northern Italy: cluster investigation and geostatistical analysis

摘要

The Aedes albopictus (Skuse) (Diptera Culicidae) control program currently applied in the Emilia-Romagna region (Northern Italy) is based on the use of ovitraps as a tool for mosquito population density estimation. During the favourable season 2008 (May-October), 2,741 ovitraps were activated in the urban areas of 242 municipalities according to standard criteria and were checked weekly. The universal kriging interpolation was used to estimate the seasonal abundance of the species at unsampled locations, and spatial cluster analysis was used to identify particular areas that had statistically significant high or low mosquito density. The overall data pattern was highly clustered and autocorrelated, and the choropleth and LISA cluster maps showed high egg density in the North, North-East and in the South-West areas of the region. The cross-validation statistics and results showed that the predicted values were reasonable for map production. The characterization of large geographic areas with high or low abundance of Ae. albopictus may provide information both on the environmental variables that promote species dispersion, and on the epidemic diseases risk, essential to develop effective disease surveillance programs, particularly for Chikungunya and Dengue.