title: Seasonal and regional dynamics of M. ulcerans transmission in environmental context: deciphering the role of water bugs as hosts and vectors.
abstract: BACKGROUND
  Buruli ulcer, the third mycobacterial disease after tuberculosis and leprosy, is caused by the environmental mycobacterium M. ulcerans. Various modes of transmission have been suspected for this disease, with no general consensus acceptance for any of them up to now. Since laboratory models demonstrated the ability of water bugs to transmit M. ulcerans, a particular attention is focused on the transmission of the bacilli by water bugs as hosts and vectors. However, it is only through detailed knowledge of the biodiversity and ecology of water bugs that the importance of this mode of transmission can be fully assessed. It is the objective of the work here to decipher the role of water bugs in M. ulcerans ecology and transmission, based on large-scale field studies.
  
  
  RESULTS
  The distribution of M. ulcerans-hosting water bugs was monitored on previously unprecedented time and space scales: a total of 7,407 water bugs, belonging to large number of different families, were collected over one year, in Buruli ulcer endemic and non endemic areas in central Cameroon. This study demonstrated the presence of M. ulcerans in insect saliva. In addition, the field results provided a full picture of the ecology of transmission in terms of biodiversity and detailed specification of seasonal and regional dynamics, with large temporal heterogeneity in the insect tissue colonization rate and detection of M. ulcerans only in water bug tissues collected in Buruli ulcer endemic areas.
  
  
  CONCLUSIONS
  The large-scale detection of bacilli in saliva of biting water bugs gives enhanced weight to their role in M. ulcerans transmission. On practical grounds, beyond the ecological interest, the results concerning seasonal and regional dynamics can provide an efficient tool in the hands of sanitary authorities to monitor environmental risks associated with Buruli ulcer.
authors.affiliation: Groupe d'Etude des Interactions Hôte-Pathogène, Université d'Angers, Angers, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Marion
authors.forename: Sara
authors.initials: S
authors.lastname: Eyangoh
authors.forename: Edouard
authors.initials: E
authors.lastname: Yeramian
authors.forename: Julien
authors.initials: J
authors.lastname: Doannio
authors.forename: Jordi
authors.initials: J
authors.lastname: Landier
authors.forename: Jacques
authors.initials: J
authors.lastname: Aubry
authors.forename: Arnaud
authors.initials: A
authors.lastname: Fontanet
authors.forename: Christophe
authors.initials: C
authors.lastname: Rogier
authors.forename: Viviane
authors.initials: V
authors.lastname: Cassisa
authors.forename: Jane
authors.initials: J
authors.lastname: Cottin
authors.forename: Agnès
authors.initials: A
authors.lastname: Marot
authors.forename: Matthieu
authors.initials: M
authors.lastname: Eveillard
authors.forename: Yannick
authors.initials: Y
authors.lastname: Kamdem
authors.forename: Pierre
authors.initials: P
authors.lastname: Legras
authors.forename: Caroline
authors.initials: C
authors.lastname: Deshayes
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Saint-André
authors.forename: Laurent
authors.initials: L
authors.lastname: Marsollier
mesh_terms: D000818:Animals; D054312:Buruli Ulcer / Q000635:transmission; D002163:Cameroon; D004195:Disease Models, Animal; D004199:Disease Vectors; D005260:Female; D005843:Geography; D020062:Heteroptera / Q000382:microbiology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D019911:Mycobacterium ulcerans / Q000302:isolation & purification*; D012463:Saliva / Q000382:microbiology; D012621:Seasons