title: Emergence and potential for spread of Chikungunya virus in Brazil.
abstract: BACKGROUND
  In December 2013, an outbreak of Chikungunya virus (CHIKV) caused by the Asian genotype was notified in the Caribbean. The outbreak has since spread to 38 regions in the Americas. By September 2014, the first autochthonous CHIKV infections were confirmed in Oiapoque, North Brazil, and in Feira de Santana, Northeast Brazil.
  
  
  METHODS
  We compiled epidemiological and clinical data on suspected CHIKV cases in Brazil and polymerase-chain-reaction-based diagnostic was conducted on 68 serum samples from patients with symptom onset between April and September 2014. Two imported and four autochthonous cases were selected for virus propagation, RNA isolation, full-length genome sequencing, and phylogenetic analysis. We then followed CDC/PAHO guidelines to estimate the risk of establishment of CHIKV in Brazilian municipalities.
  
  
  RESULTS
  We detected 41 CHIKV importations and 27 autochthonous cases in Brazil. Epidemiological and phylogenetic analyses indicated local transmission of the Asian CHIKV genotype in Oiapoque. Unexpectedly, we also discovered that the ECSA genotype is circulating in Feira de Santana. The presumed index case of the ECSA genotype was an individual who had recently returned from Angola and developed symptoms in Feira de Santana. We estimate that, if CHIKV becomes established in Brazil, transmission could occur in 94% of municipalities in the country and provide maps of the risk of importation of each strain of CHIKV in Brazil.
  
  
  CONCLUSIONS
  The etiological strains associated with the early-phase CHIKV outbreaks in Brazil belong to the Asian and ECSA genotypes. Continued surveillance and vector mitigation strategies are needed to reduce the future public health impact of CHIKV in the Americas.
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. marcionunesbrasil@yahoo.com.br.
authors.forename: Marcio Roberto Teixeira
authors.initials: MR
authors.lastname: Nunes
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK. nuno.faria@zoo.ox.ac.uk.
authors.forename: Nuno Rodrigues
authors.initials: NR
authors.lastname: Faria
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. janaina.mvasconcelos@yahoo.com.br.
authors.forename: Janaina Mota
authors.initials: JM
authors.lastname: de Vasconcelos
authors.affiliation: Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK. nick.golding@zoo.ox.ac.uk.
authors.forename: Nick
authors.initials: N
authors.lastname: Golding
authors.affiliation: Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK. moritz.kraemer@zoo.ox.ac.uk.
authors.forename: Moritz U G
authors.initials: MU
authors.lastname: Kraemer
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. layannafoliveira@gmail.com.
authors.forename: Layanna Freitas
authors.initials: LF
authors.lastname: de Oliveira
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. raimundaazevedo@iec.pa.gov.br.
authors.forename: Raimunda do Socorro da Silva
authors.initials: Rdo S
authors.lastname: Azevedo
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. daisydasilva@gmail.com.
authors.forename: Daisy Elaine Andrade
authors.initials: DE
authors.lastname: da Silva
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. elianapinto@iec.pa.gov.br.
authors.forename: Eliana Vieira Pinto
authors.initials: EV
authors.lastname: da Silva
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. spatroca@gmail.com.
authors.forename: Sandro Patroca
authors.initials: SP
authors.lastname: da Silva
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. valeriacarvalho@iec.pa.gov.br.
authors.forename: Valéria Lima
authors.initials: VL
authors.lastname: Carvalho
authors.affiliation: National Dengue Control Program, Brazilian Ministry of Health, Brasilia, DF, 70058-900, Brazil. giovanini.coelho@saude.gov.br.
authors.forename: Giovanini Evelim
authors.initials: GE
authors.lastname: Coelho
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. anacecilia@iec.pa.gov.br.
authors.forename: Ana Cecília Ribeiro
authors.initials: AC
authors.lastname: Cruz
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. suelirodrigues@iec.pa.gov.br.
authors.forename: Sueli Guerreiro
authors.initials: SG
authors.lastname: Rodrigues
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. joao.vianezjr@gmail.com.
authors.forename: Joao Lídio da Silva Gonçalves
authors.initials: JL
authors.lastname: Vianez
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. brunonunes@iec.pa.gov.br.
authors.forename: Bruno Tardelli Diniz
authors.initials: BT
authors.lastname: Nunes
authors.affiliation: Center for Technological Innovation, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. jedson.cardoso@iec.pa.gov.br.
authors.forename: Jedson Ferreira
authors.initials: JF
authors.lastname: Cardoso
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, Texas TX, 77555-0609, USA. rtesh@utmb.edu.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Tesh
authors.affiliation: Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK. simon.i.hay@gmail.com.|Fogarty International Center, National Institutes of Health, Bethesda, MD, 20892, USA. simon.i.hay@gmail.com.
authors.forename: Simon I
authors.initials: SI
authors.lastname: Hay
authors.affiliation: Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK. oliver.pybus@zoo.ox.ac.uk.
authors.forename: Oliver G
authors.initials: OG
authors.lastname: Pybus
authors.affiliation: Department of Arbovirology and Hemorrhagic Fevers, Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, 67030-000, Brazil. pedro.vasconcelos@globo.com.|Department of Pathology, Para State University, Belem, PA, 66087-670, Brazil. pedro.vasconcelos@globo.com.
authors.forename: Pedro Fernando da Costa
authors.initials: PF
authors.lastname: Vasconcelos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D065632:Chikungunya Fever / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology*; D002646:Chikungunya virus / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D011634:Public Health; D012306:Risk; D055815:Young Adult