Molecular epidemiological study of dengue virus type 1 in Taiwan

Abstract

Taiwan has experienced several major outbreaks of dengue (DEN) virus since 1981. The predominant virus type involved has been dengue virus type one (DEN-1), which first appeared in 1987. To understand the molecular epidemiology of this virus, 15 strains of DEN-1 isolated during 1987-1991 and 1994-1995, including 11 epidemic strains, two sporadic strains, and two imported strains have been studied. Fragments of 490 nucleotides (nt) from the E/NS1 junction were amplified by reverse transcription-polymerase chain reaction and the nt sequences were determined. Of the 490 nt of the E/NS1 junction, 240 nt (nt 2282-2521) were aligned and compared. Nucleotide substitutions were found at 54 positions among 15 isolates. Most nt changes were synonymous substitutions, and only three amino acid changes were found. A total of 61 strains isolated worldwide were analyzed by the Neighbor-joining method, and separated phylogenetically into three distinct genotypes, I-III. Genotype I comprised isolates from Japan and Hawaii collected in the 1940s. Genotype II included most strains isolated from Asia in 1977-1995. Genotype III consisted of isolates from three continents in 1964-1995: Asia, the Americas, and Africa. Genotype III was divided further into two subgenotypes, IIIA and IIIB. Most recent isolates from Taiwan, except for the sporadic strain isolated in 1995, were similar genetically and have been classified as Genotype II.

Altered T helper 1 reaction but not increase of virus load in patients with dengue hemorrhagic fever

“…Another important finding identified in this study is that the first large DHF outbreak of DEN‐2 in Taiwan occurred in an adult patient population. A previous DEN‐1 outbreak in Kaohsiung [37] did not have any DHF case reported and another small series of DEN‐3 outbreak reported sporadic DHF cases in Tainan, Taiwan [38]. All the DHF patients in this outbreak were adult patients.…”

Use of a Short Fragment of the C-Terminal E Gene for Detection and Characterization of Two New Lineages of Dengue Virus 1 in India

“…Three (2,15,24) to five (7, 29) different genotypes of DENV-1 have been proposed. Our analysis of complete E gene sequences confirmed the presence of five genotypes and the clustering of sequences below the genotype level that correlate with the geographical origin and/or time of isolation and appear to represent distinct lineages with strong bootstrap support (Fig.…”

Spatiotemporal Dynamics and Epistatic Interaction Sites in Dengue Virus Type 1: A Comprehensive Sequence-Based Analysis

“…The RNA was eluted in 50μl of RNase free water and stored at -80°C until use. Reverse transcription (RT) and polymerase chain reaction (PCR) were performed as previously described [31,32]. Briefly, fragments of PCR products were amplified with the primer sets as shown in Table S2.…”