Fig. 3: Risk of onward transmission from entomological data.

Estimated mean basic reproduction number (R0) for DENV (top) and CHIKV (bottom) in Italy at the beginning of August during the outbreak years, assuming Ae. albopictus as the primary vector species. Estimates are provided at a 100 m × 100 m spatial resolution and are shown only for areas with a population density of at least ten inhabitants per hectare and where the estimated R0 exceeds 0.1. Values are displayed as proportional to the population size to highlight potential epidemic risks and represent the average estimate of 500 model runs. Maps also show the locations and sizes of historically observed outbreaks.