title: [Yellow fever: reemerging in the state of Sao Paulo, Brazil, 2009].
abstract: OBJECTIVE
  To describe the investigation of a sylvatic yellow fever outbreak in the state of Sao Paulo and the main control measures undertaken.
  
  
  METHODS
  This is a descriptive study of a sylvatic yellow fever outbreak in the Southwestern region of the state from February to April 2009. Suspected and confirmed cases in humans and in non-human primates were evaluated. Entomological investigation in sylvatic environment involved capture at ground level and in the tree canopy to identify species and detect natural infections. Control measures were performed in urban areas to control Aedes aegypti . Vaccination was directed at residents living in areas with confirmed viral circulation and also at nearby cities according to national recommendation.
  
  
  RESULTS
  Twenty-eight human cases were confirmed (39.3% case fatality rate) in rural areas of Sarutaiá, Piraju, Tejupá, Avaré and Buri. The deaths of 56 non-human primates were also reported, 91.4% were Allouatta sp. Epizootics was confirmed in two non-human primates in the cities of Itapetininga and Buri. A total of 1,782 mosquitoes were collected, including Haemagogus leucocelaenus , Hg. janthinomys/capricornii , and Sabethes chloropterus, Sa. purpureus and Sa. undosus . Yellow fever virus was isolated from a group of Hg. Leucocelaenus from Buri. Vaccination was carried out in 49 cities, with a total of 1,018,705 doses. Nine serious post-vaccination adverse events were reported.
  
  
  CONCLUSIONS
  The cases occurred between February and April 2009 in areas with no recorded yellow fever virus circulation in over 60 years. The outbreak region occurred outside the original recommended vaccination area with a high percentage of susceptible population. The fast adoption of control measures interrupted the human transmission within a month and the confirmation of viral circulation in humans, monkeys and mosquitoes. The results allowed the identification of new areas of viral circulation but further studies are required to clarify the dynamics of the spread of this disease.
authors.forename: Melissa
authors.initials: M
authors.lastname: Mascheretti
authors.forename: Ciléa H
authors.initials: CH
authors.lastname: Tengan
authors.forename: Helena Keiko
authors.initials: HK
authors.lastname: Sato
authors.forename: Akemi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Renato Pereira
authors.initials: RP
authors.lastname: de Souza
authors.forename: Marina
authors.initials: M
authors.lastname: Maeda
authors.forename: Roosecelis
authors.initials: R
authors.lastname: Brasil
authors.forename: Mariza
authors.initials: M
authors.lastname: Pereira
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Tubaki
authors.forename: Dalva M V
authors.initials: DM
authors.lastname: Wanderley
authors.forename: Carlos Magno Castelo Branco
authors.initials: CM
authors.lastname: Fortaleza
authors.forename: Ana Freitas
authors.initials: AF
authors.lastname: Ribeiro
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D021821:Communicable Diseases, Emerging / Q000453:epidemiology* / Q000662:veterinary; D009033:Culicidae / Q000145:classification*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007303:Insect Vectors / Q000145:classification*; D008297:Male; D008875:Middle Aged; D015004:Yellow Fever / Q000453:epidemiology* / Q000662:veterinary; D055815:Young Adult