Entomologic and virologic investigation of Chikungunya, Singapore

• Published in: Emerging infectious diseases Vol. 15; no. 8; pp. 1243 - 1249
• Main Authors: Ng, Lee-Ching, Tan, Li-Kiang, Tan, Cheong-Huat, Tan, Sharon S Y, Hapuarachchi, Hapuarachchige C, Pok, Kwoon-Yong, Lai, Yee-Ling, Lam-Phua, Sai-Gek, Bucht, Göran, Lin, Raymond T P, Leo, Yee-Sin, Tan, Boon-Hian, Han, Hwi-Kwang, Ooi, Peng-Lim S, James, Lyn, Khoo, Seow-Poh
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01.08.2009; Centers for Disease Control and Prevention
• Subjects: Aedes - virology; Aedes aegypti; Alphavirus Infections - epidemiology; Alphavirus Infections - transmission; Alphavirus Infections - virology; Amino Acid Substitution; Animals; Base Sequence; Biological products industry; Chikungunya; chikungunya virus; Chikungunya virus - genetics; Chikungunya virus - isolation & purification; Communicable Diseases, Emerging - epidemiology; Communicable Diseases, Emerging - transmission; Communicable Diseases, Emerging - virology; Disease Outbreaks; Disease transmission; DNA Primers - genetics; DNA, Viral - genetics; entomology; Genes, env; Genetic aspects; Humans; Insect Vectors - virology; Molecular Epidemiology; Mosquitoes; Phylogeny; sequencing; Singapore - epidemiology; surveillance; Viral Envelope Proteins - genetics; virology; Singapore; ISEW, Singapore; ISW, Indian Ocean
• ISSN: 1080-6040; 1080-6059
• DOI: 10.3201/eid1508.081486

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.