title: Molecular characterization of chikungunya virus circulating in urban and rural areas of West Bengal, India after its re-emergence in 2006.
abstract: BACKGROUND
  In the state of West Bengal, chikungunya virus (CHIKV) has re-emerged in 2006 after its last occurrence in 1963-1965 in this state. The virus rapidly affected almost every district of this state, with high morbidity. Based on complete sequences of structural region of CHIKV genome, we determined the molecular characterization of the virus circulating in this state from 2006-2012.
  
  
  METHODS
  CHIKV was isolated from 20 acute CHIKV RT-PCR positive serum samples in C6/36 mosquito cell line. These samples were collected from 20 patients with a clinical history of ≤2 days of fever and chikungunya-like illness. Those patients were residing in some outbreak areas in the state of West Bengal during 2006-2012. Isolation was confirmed through RT-PCR and sequencing.
  
  
  CONCLUSIONS
  Two sub-lineages of East-central-southern African (ECSA) genotype of CHIKV strains were circulating simultaneously in this state during the study period; one type was circulating in rural areas of the state from 2006 whereas another type was isolated from the metropolitan city of Kolkata in 2011 and 2012. The mutational pattern of those CHIKV strains suggests that the transmission of the viruses might be facilitated by different species of Aedes mosquitoes. Our results represent an important first step towards understanding the circulating strains of CHIKV in the state of West Bengal with the geographical variation.
authors.affiliation: ICMR Virus Unit, GB4, 1st floor, ID & BG Hospital, Dr. S.C. Banerjee Road, Beliaghata, Kolkata, India.
authors.forename: Debjani
authors.initials: D
authors.lastname: Taraphdar
authors.affiliation: ICMR Virus Unit, GB4, 1st floor, ID & BG Hospital, Dr. S.C. Banerjee Road, Beliaghata, Kolkata, India shyamalendu.chatterjee1@gmail.com.
authors.forename: Shyamalendu
authors.initials: S
authors.lastname: Chatterjee
mesh_terms: D065632:Chikungunya Fever / Q000453:epidemiology / Q000821:virology*; D002646:Chikungunya virus / Q000235:genetics* / Q000302:isolation & purification*; D021821:Communicable Diseases, Emerging / Q000453:epidemiology / Q000821:virology*; D004196:Disease Outbreaks; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D009154:Mutation; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000032:analysis; D012424:Rural Population; D014505:Urban Population
chemical_list: D012367:RNA, Viral
keywords: Chikungunya virus; India; Molecular characterization; West Bengal