Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
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Infect. Genet. Evol. · Jul 2012
Molecular investigations of chikungunya virus during outbreaks in Orissa, Eastern India in 2010.
Chikungunya virus (CHIKV), an arthritogenic alphavirus, is transmitted to humans by mosquitoes of genus Aedes, mainly Aedes aegypti and Aedes albopictus. The resurgence of CHIKV in different parts of India is a point of major public health concern. In 2010, chikungunya outbreaks with high epidemic magnitude were recorded in coastal areas of Orissa, Eastern India, affecting more than 15,000 people coupled with severe arthralgia and prolonged morbidites. ⋯ Phylogenetic analysis revealed that the CHIKV strains involved in the outbreak belonged to the Indian Ocean Lineage (IOL) group within the East, Central and South African (ECSA) genotype. Genetic characterization of envelope glycoprotein (E1 and E2) genes revealed that all the CHIKV isolates from Orissa had the E1-A226V mutation that enhances viral dissemination and transmissibility by A. albopictus mosquitoes along with E2-L210Q and E2-I211T mutations, which play an epistatic role with E1-A226V mutation in adaptation of CHIKV to A. albopictus by increasing its midgut infectivity, thereby favoring its vectorial capacity. Our results showed the involvement of A. albopictus vector in the recent outbreaks in Orissa and circulation of IOL strains of ECSA genotype of CHIKV with E1-A226V, E2-L210Q and E2-I211T mutations in vectors and patients serum.