title: Infectious keratoconjunctivitis in wild Caprinae: merging field observations and molecular analyses sheds light on factors shaping outbreak dynamics.
abstract: BACKGROUND
  Infectious keratoconjunctivitis (IKC) is an ocular infectious disease caused by Mycoplasma conjunctivae which affects small domestic and wild mountain ruminants. Domestic sheep maintain the pathogen but the detection of healthy carriers in wildlife has raised the question as to whether M. conjunctivae may also persist in the wild. Furthermore, the factors shaping the dynamics of IKC outbreaks in wildlife have remained largely unknown. The aims of this study were (1) to verify the etiological role of M. conjunctivae in IKC outbreaks recorded between 2002 and 2010 at four study sites in different regions of France (Pyrenees and Alps, samples from 159 Alpine ibex Capra ibex, Alpine chamois Rupicapra rupicapra and Pyrenean chamois Rupicapra pyrenaica); (2) to establish whether there existed any epidemiological links between the different regions through a cluster analysis of the detected strains (from 80 out of the 159 animals tested); (3) to explore selected pathogen, host and environmental factors potentially influencing the dynamics of IKC in wildlife, by joining results obtained by molecular analyses and by field observations (16,609 animal observations). All of the samples were tested for M. conjunctivae by qPCR, and cluster analysis was based on a highly variable part of the lppS gene.
  
  
  RESULTS
  We documented infections with M. conjunctivae in epidemic and endemic situations, both in symptomatic and asymptomatic animals. The identified M. conjunctivae strains were site-specific and persisted in the local wild population for at least 6 years. In epidemic situations, peaks of cases and disease resurgence were associated with the emergence of new similar strains in a given area. Social interactions, seasonal movements and the landscape structure such as natural and anthropogenic barriers influenced the spatio-temporal spread of IKC. Adults were more affected than young animals and host susceptibility differed depending on the involved strain.
  
  
  CONCLUSIONS
  Our study indicates that IKC is a multifactorial disease and that M. conjunctivae can persist in wildlife populations. The disease course in individual animals and populations is influenced by both host and mycoplasma characteristics, and the disease spread within and among populations is shaped by host behavior and landscape structure.
authors.affiliation: Centre for Fish and Wildlife Health (FIWI), Vetsuisse Faculty, University of Bern, Bern, Switzerland.|Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Gelormini
authors.affiliation: Laboratoire Vétérinaire des Hautes Alpes, Gap, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Gauthier
authors.affiliation: Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Edy M
authors.initials: EM
authors.lastname: Vilei
authors.affiliation: Parc National des Pyrénées, Tarbes, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Crampe
authors.affiliation: Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Joachim
authors.initials: J
authors.lastname: Frey
authors.affiliation: Centre for Fish and Wildlife Health (FIWI), Vetsuisse Faculty, University of Bern, Bern, Switzerland. marie-pierre.ryser@vetsuisse.unibe.ch.
authors.forename: Marie-Pierre
authors.identifier: http://orcid.org/0000-0003-1062-870X
authors.initials: MP
authors.lastname: Ryser-Degiorgis
mesh_terms: D000375:Aging; D000818:Animals; D000835:Animals, Wild; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D005602:France / Q000453:epidemiology; D015511:Goat Diseases / Q000453:epidemiology / Q000473:pathology*; D006041:Goats; D007639:Keratoconjunctivitis, Infectious / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D008297:Male; D013997:Time Factors
keywords: Chamois; Disease spread; Ibex; Molecular epidemiology; Mycoplasma conjunctivae; Ocular disease; Persistence; Resurgence