Figure A1. Dengue virus (DENV) serotype 2 case distribution, Puerto Rico, 1987–2006. Maps of Puerto Rico are shown as examples of distribution of total of DENV-2 cases reported on the island during 4 different years representing clade II expansion (1987) (A), clades II/I mixing (1995) (B), low evolution of subclade IB (2001) (C), and resurgence of subclade IB (D). All maps represent the 78 municipalities of Puerto Rico. White, 0–1 DENV-2 identifications; gray, 2–5 DENV-2 identifications; black, >6 DENV-2 identifications. Maximum number of identifications in any 1 municipality was 17.