title: Zika virus infection, associated microcephaly, and low yellow fever vaccination coverage in Brazil: is there any causal link?
abstract: BACKGROUND
  Since the end of 2014, Zika virus (ZIKV) infection has been rapidly spreading in Brazil.
  
  
  METHODS
  To analyze the possible association of yellow fever vaccine with a protective effect against ZIKV-related microcephaly, the following spatial analyses were performed, using Brazilian municipalities as units: i) yellow fever vaccination coverage in Brazilian municipalities in individuals aged 15-49; ii) reported cases of microcephaly by municipality; and iii) confirmed cases of microcephaly related to ZIKV, by municipality. SaTScan software was used to identify clusters of municipalities for high risk of microcephaly.
  
  
  RESULTS
  There were seven significant high risk clusters of confirmed microcephaly cases, with four of them located in the Northeast where yellow fever vaccination rates were the lowest. The clusters harbored only 2.9% of the total population of Brazil, but 15.2% of confirmed cases of microcephaly.
  
  
  CONCLUSIONS
  We hypothesize that pregnant women in regions with high yellow fever vaccination coverage may pose their offspring to lower risk for development of microcephaly. There is an urgent need for systematic studies to confirm the possible link between low yellow fever vaccination coverage, Zika virus infection and microcephaly.
authors.affiliation: Federal University of Ceará, Fortaleza, CE, Brazil. pamplona.luciano@gmail.com.
authors.forename: Luciano Pamplona
authors.initials: LP
authors.lastname: De Góes Cavalcanti
authors.forename: Pedro Luiz
authors.initials: PL
authors.lastname: Tauil
authors.forename: Carlos Henrique
authors.initials: CH
authors.lastname: Alencar
authors.forename: Wanderson
authors.initials: W
authors.lastname: Oliveira
authors.forename: Mauro Martins
authors.initials: MM
authors.lastname: Teixeira
authors.forename: Jorg
authors.initials: J
authors.lastname: Heukelbach
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006801:Humans; D008831:Microcephaly / Q000453:epidemiology* / Q000517:prevention & control*; D008875:Middle Aged; D011247:Pregnancy; D018570:Risk Assessment; D062206:Spatial Analysis; D019371:Topography, Medical; D014611:Vaccination / Q000706:statistics & numerical data*; D015004:Yellow Fever / Q000517:prevention & control*; D022341:Yellow Fever Vaccine / Q000008:administration & dosage*; D055815:Young Adult; D000071243:Zika Virus Infection / Q000150:complications* / Q000453:epidemiology*
chemical_list: D022341:Yellow Fever Vaccine