Molecular and Virological Analyses of Dengue Virus Responsible for Dengue Outbreak in East Timor in 2005

Abstract

A severe dengue outbreak occurred in East Timor in 2005. The dengue virus genome was detected by TaqMan RT-PCR in 40 serum samples, as follows: dengue virus type-3 (DENV-3) in 37 samples, DENV-2 in 2 samples, and DENV-1 in one sample. One DENV-1 genome, one DENV-2 genome, and 5 DENV-3 genomes were sequenced, and these specimens were aligned with the previously determined envelope (E) gene sequences. The DENV-1 strain belonged to genotype IV and was close to those previously isolated in Indonesia and Australia. The DENV-2 strain belonged to genotype I and was close to those previously isolated in Indonesia, Australia, the Far East, and India in 1993-2001. The DENV-3 strain belonged to genotype I and was close to those previously isolated in Indonesia. The results indicate that the dengue outbreak was caused mainly by DENV-3, with DENV-1 and DENV-2 as minor serotypes, and suggest that these strains of 3 serotypes of DENV entered East Timor from neighboring countries, co-circulated, and caused the dengue outbreak in 2005.