title: Ecological niche modelling of Hemipteran insects in Cameroon; the paradox of a vector-borne transmission for Mycobacterium ulcerans, the causative agent of Buruli ulcer.
abstract: BACKGROUND
  The mode of transmission of the emerging neglected disease Buruli ulcer is unknown. Several potential transmission pathways have been proposed, such as amoebae, or transmission through food webs. Several lines of evidence have suggested that biting aquatic insects, Naucoridae and Belostomatidae, may act as vectors, however this proposal remains controversial.
  
  
  METHODS
  Herein, based on sampling in Cameroon, we construct an ecological niche model of these insects to describe their spatial distribution. We predict their distribution across West Africa, describe important environmental drivers of their abundance, and examine the correlation between their abundance and Buruli ulcer prevalence in the context of the Bradford-Hill guidelines.
  
  
  RESULTS
  We find a significant positive correlation between the abundance of the insects and the prevalence of Buruli ulcer. This correlation changes in space and time, it is significant in one Camerounese study region in (Akonolinga) and not other (Bankim). We discuss notable environmental differences between these regions.
  
  
  CONCLUSIONS
  We interpret the presence of, and change in, this correlation as evidence (though not proof) that these insects may be locally important in the environmental persistence, or transmission, of Mycobacterium. ulcerans. This is consistent with the idea of M. ulcerans as a pathogen transmitted by multiple modes of infection, the importance of any one pathway changing from region to region, depending on the local environmental conditions.
authors.affiliation: Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs : Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, BP 64501, 34394 Montpellier Cedex 5, France. kevin.carolan@ird.fr.
authors.forename: Kevin
authors.initials: K
authors.lastname: Carolan
authors.forename: Solange Meyin A
authors.initials: SM
authors.lastname: Ebong
authors.forename: Andres
authors.initials: A
authors.lastname: Garchitorena
authors.forename: Jordi
authors.initials: J
authors.lastname: Landier
authors.forename: Daniel
authors.initials: D
authors.lastname: Sanhueza
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Texier
authors.forename: Laurent
authors.initials: L
authors.lastname: Marsollier
authors.forename: Philipe Le
authors.initials: PL
authors.lastname: Gall
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Guégan
authors.forename: Danny
authors.initials: D
authors.lastname: Lo Seen
mesh_terms: D000818:Animals; D054312:Buruli Ulcer / Q000453:epidemiology / Q000635:transmission*; D002163:Cameroon / Q000453:epidemiology; D017753:Ecosystem; D062305:Geographic Mapping; D006430:Hemiptera; D006801:Humans; D007303:Insect Vectors / Q000382:microbiology; D019911:Mycobacterium ulcerans / Q000302:isolation & purification*