Concurrent isolation of chikungunya virus and dengue virus from a patient with coinfection resulting from a trip to Singapore

Abstract

We report two cases of imported infection in patients who had returned to Taiwan from Singapore: one was coinfected with chikungunya virus and dengue virus type 2, and the other was infected with the same dengue virus. Both viruses were successfully isolated from the coinfected case by using antibody neutralization and a plaque purification technique.

FIG. 1.

Phylogenetic analysis of the complete envelope 1 (E1) gene (1,317 nucleotides [nt]) of a chikungunya virus (CHIKV) isolate from a patient who had returned from Singapore coinfected with CHIKV and dengue virus. The sequence obtained in this study is designated by boldface type. CHIKV strains with the E1-A226V mutation are indicated. Viruses are identified by virus/country/strain/year of isolation/GenBank accession number. The analysis was performed using MEGA 4 software, with the neighbor-joining (maximum-composite-likelihood) method. Bootstrap support values of >60 are shown (1,000 replicates). The scale bar on the left indicates the number of nucleotide substitutions per site.

FIG. 2.

Phylogenetic analysis of the complete envelope gene (1,485 nt) of dengue virus type 2 isolates from two patients (case 1 and case 2) who had returned from Singapore. Sequences obtained in this study are designated by boldface type. Viruses are identified by virus/country/strain/year of isolation/GenBank accession number. The analysis was performed using MEGA 4 software, with the neighbor-joining (maximum-composite-likelihood) method. Bootstrap support values of >75 are shown (1,000 replicates). The scale bar on the left indicates the number of nucleotide substitutions per site.