Figure 1.

Dengue fever (DF) outbreaks in Taiwan during 2014–2015. (A) Phylogenetic tree analyses of Taiwanese 2014 (the right) and 2015 (the left) dengue serotype 1 and 2 outbreak-associated isolates. The nucleotide sequences of complete E-genes of DENV strains were aligned, edited and analyzed using ClustalW software (http://bioedit.software.informer.com/7.2/). The phylogenetic analysis was performed using MEGA version 5. Consensus neighbor-joining trees were obtained from 1000 bootstrap replicates.⁸ The red-filled circles and blue-filled squares indicate DENV-2 isolated from Kaohsiung and Tainan in the 2015 severe DF outbreak. The black-outlined and black-filled squares indicate the 2014 outbreak-associated DENV-1 isolates and 2015 DENV-1 epidemic strains in Kaohsiung city. The gray-filled diamonds in both phylogenetic trees indicate previous Taiwanese DENV epidemic strains. (B) The accumulative dengue infection cases in the past decade (left) and reported cases monthly in 2014–2015 (right) in Taiwan are shown. The association of dengue case numbers with temperature and precipitation is also illustrated. The asterisk (*) indicates the time of the gas explosion in Kaohsiung city.