RESUMO
In Singapore, after a major outbreak of dengue in 2005, another outbreak occurred in 2007. Laboratory-based surveillance detected a switch from dengue virus serotype 1 (DENV-1) to DENV-2. Phylogenetic analysis showed a clade replacement within DENV-2 cosmopolitan genotype, which accompanied the predominant serotype switch, and cocirculation of multiple genotypes of DENV-3.
Assuntos
Vírus da Dengue/genética , Dengue/epidemiologia , Vigilância da População , Aedes/virologia , Animais , Dengue/virologia , Vírus da Dengue/classificação , Vírus da Dengue/isolamento & purificação , Surtos de Doenças , Humanos , Insetos Vetores/virologia , Dados de Sequência Molecular , Controle de Mosquitos , Filogenia , RNA Viral/análise , RNA Viral/genética , Análise de Sequência de DNA , Sorotipagem , Singapura/epidemiologia , Proteínas do Envelope Viral/análise , Proteínas do Envelope Viral/genéticaRESUMO
Local transmission of chikungunya, a debilitating mosquito-borne viral disease, was first reported in Singapore in January 2008. After 3 months of absence, locally acquired Chikungunya cases resurfaced in May 2008, causing an outbreak that resulted in a total of 231 cases by September 2008. The circulating viruses were related to East, Central, and South African genotypes that emerged in the Indian Ocean region in 2005. The first local outbreak was due to a wild-type virus (alanine at codon 226 of the envelope 1 gene) and occurred in an area where Aedes aegypti mosquitoes were the primary vector. Strains isolated during subsequent outbreaks showed alanine to valine substitution (A226V) and largely spread in areas predominated by Ae. albopictus mosquitoes. These findings led to a revision of the current vector control strategy in Singapore. This report highlights the use of entomologic and virologic data to assist in the control of chikungunya in disease-endemic areas.