title: The global distribution of Crimean-Congo hemorrhagic fever.
abstract: BACKGROUND
  Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne infection caused by a virus (CCHFV) from the Bunyaviridae family. Domestic and wild vertebrates are asymptomatic reservoirs for the virus, putting animal handlers, slaughter-house workers and agricultural labourers at highest risk in endemic areas, with secondary transmission possible through contact with infected blood and other bodily fluids. Human infection is characterized by severe symptoms that often result in death. While it is known that CCHFV transmission is limited to Africa, Asia and Europe, definitive global extents and risk patterns within these limits have not been well described.
  
  
  METHODS
  We used an exhaustive database of human CCHF occurrence records and a niche modeling framework to map the global distribution of risk for human CCHF occurrence.
  
  
  RESULTS
  A greater proportion of shrub or grass land cover was the most important contributor to our model, which predicts highest levels of risk around the Black Sea, Turkey, and some parts of central Asia. Sub-Saharan Africa shows more focalized areas of risk throughout the Sahel and the Cape region.
  
  
  CONCLUSIONS
  These new risk maps provide a valuable starting point for understanding the zoonotic niche of CCHF, its extent and the risk it poses to humans.
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK jane.messina@zoo.ox.ac.uk.
authors.forename: Jane P
authors.initials: JP
authors.lastname: Messina
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Pigott
authors.affiliation: Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Golding
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Duda
authors.affiliation: Department of Pediatrics, Harvard Medical School and Children's Hospital Informatics Program, Boston Children's Hospital, Boston, MA, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Brownstein
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Weiss
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Harry
authors.initials: H
authors.lastname: Gibson
authors.affiliation: Livestock Systems and Environment (LSE), International Livestock Research Institute (ILRI),Nairobi, Kenya.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Robinson
authors.affiliation: Biological Control and Spatial Ecology, Université Libre de Bruxelles, Brussels, Belgium Fonds National de la Recherche Scientifique, Brussels, Belgium.
authors.forename: Marius
authors.initials: M
authors.lastname: Gilbert
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: G R
authors.initials: GR
authors.lastname: William Wint
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Nuttall
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Gething
authors.affiliation: Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Monica F
authors.initials: MF
authors.lastname: Myers
authors.affiliation: Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Dylan B
authors.initials: DB
authors.lastname: George
authors.affiliation: Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK Fogarty International Center, National Institutes of Health, Bethesda, MD, USA Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
authors.forename: Simon I
authors.initials: SI
authors.lastname: Hay
mesh_terms: D000003:Abattoirs; D000822:Animal Husbandry; D000818:Animals; D001096:Arachnid Vectors / Q000821:virology*; D004196:Disease Outbreaks / Q000517:prevention & control*; D000067565:Farmers; D005843:Geography; D014943:Global Health; D003225:Hemorrhagic Fever Virus, Crimean-Congo / Q000472:pathogenicity*; D006479:Hemorrhagic Fever, Crimean / Q000097:blood / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D009784:Occupational Diseases / Q000517:prevention & control* / Q000821:virology; D016273:Occupational Exposure / Q000517:prevention & control*; D010802:Phylogeny; D013987:Ticks / Q000821:virology
keywords: Crimean-Congo hemorrhagic fever; Crimean-Congo hemorrhagic fever virus; Ecological niche modeling; Infectious diseases; Tick-borne diseases; Vector-borne diseases