title: Zika virus in Gabon (Central Africa)--2007: a new threat from Aedes albopictus?
abstract: BACKGROUND
  Chikungunya and dengue viruses emerged in Gabon in 2007, with large outbreaks primarily affecting the capital Libreville and several northern towns. Both viruses subsequently spread to the south-east of the country, with new outbreaks occurring in 2010. The mosquito species Aedes albopictus, that was known as a secondary vector for both viruses, recently invaded the country and was the primary vector involved in the Gabonese outbreaks. We conducted a retrospective study of human sera and mosquitoes collected in Gabon from 2007 to 2010, in order to identify other circulating arboviruses.
  
  
  RESULTS
  Sample collections, including 4312 sera from patients presenting with painful febrile disease, and 4665 mosquitoes belonging to 9 species, split into 247 pools (including 137 pools of Aedes albopictus), were screened with molecular biology methods. Five human sera and two Aedes albopictus pools, all sampled in an urban setting during the 2007 outbreak, were positive for the flavivirus Zika (ZIKV). The ratio of Aedes albopictus pools positive for ZIKV was similar to that positive for dengue virus during the concomitant dengue outbreak suggesting similar mosquito infection rates and, presumably, underlying a human ZIKV outbreak. ZIKV sequences from the envelope and NS3 genes were amplified from a human serum sample. Phylogenetic analysis placed the Gabonese ZIKV at a basal position in the African lineage, pointing to ancestral genetic diversification and spread.
  
  
  CONCLUSIONS
  We provide the first direct evidence of human ZIKV infections in Gabon, and its first occurrence in the Asian tiger mosquito, Aedes albopictus. These data reveal an unusual natural life cycle for this virus, occurring in an urban environment, and potentially representing a new emerging threat due to this novel association with a highly invasive vector whose geographic range is still expanding across the globe.
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon.
authors: Gilda
authors: G
authors: Grard
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon ; MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France.
authors: Mélanie
authors: M
authors: Caron
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon ; MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France.
authors: Illich Manfred
authors: IM
authors: Mombo
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon ; Ministère de la Santé Publique, Libreville, Gabon.
authors: Dieudonné
authors: D
authors: Nkoghe
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon.
authors: Statiana
authors: S
authors: Mboui Ondo
authors: MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France ; URES, CIRMF, Franceville, Gabon.
authors: Davy
authors: D
authors: Jiolle
authors: MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France.
authors: Didier
authors: D
authors: Fontenille
authors: MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France ; URES, CIRMF, Franceville, Gabon.
authors: Christophe
authors: C
authors: Paupy
authors: UMVE, Centre International de Recherches Médicales de Franceville, Franceville, Gabon ; MIVEGEC, Institut de Recherche pour le Développement (IRD-224, CNRS-5290, Universités de Montpellier 1 & 2), Montpellier, France.
authors: Eric Maurice
authors: EM
authors: Leroy
mesh_terms: D000330:Aedes / Q000821:virology*; D000818:Animals; D021821:Communicable Diseases, Emerging / Q000821:virology*; D005681:Gabon / Q000453:epidemiology; D006801:Humans; D010802:Phylogeny; D012189:Retrospective Studies; D000071244:Zika Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000071243:Zika Virus Infection / Q000453:epidemiology / Q000821:virology*