Fig. 4

Spatial distribution of Breeding Percentage (BP) and transformed dengue case burden in 2003 and 2013. Left panels: values of BP are color-coded, with difference shades of green indicating BPs < 20%, yellow shades indicating BPs between 20% and 40%, and orange through dark red indicating BPs ≥ 40%. Residential grids with BP 0% in 2003 were highlighted in gray and outlined in black in the 2013 map. In 2003, areas with higher BP were exclusively in the eastern part of the island. By 2013, Ae. aegypti has expanded into the northern and western part of the island. The spatial expansion of Ae. aegypti is also illustrated by areas that turn from a BP of 0% to having a BP of > 0%. Furthermore, areas that had relatively higher BPs in 2003 also registered higher levels of BPs in 2013, as visualized by the color gradient. Right panels: transformed dengue case burden in residential grids in 2003 and 2013 are represented by colors, with green being the least dengue burden and dark red being the highest burden. Vertical comparisons illustrate the spatial expansion of Ae. aegypti and dengue transmission. Horizontal comparisons reveal a likely association between BP and dengue transmission