title: Outbreak of urogenital schistosomiasis in Corsica (France): an epidemiological case study.
abstract: Schistosomiasis is a snail-borne parasitic disease endemic in several tropical and subtropical countries. However, in the summer of 2013, an unexpected outbreak of urogenital schistosomiasis occurred in Corsica, with more than 120 local people or tourists infected. We used a multidisciplinary approach to investigate the epidemiology of urogenital schistosomiasis in Corsica, aiming to elucidate the origin of the outbreak.
  
  
  
  We did parasitological and malacological surveys at nine potential sites of infection. With the snails found, we carried out snail-parasite compatibility experiments by exposing snails to schistosome larvae recovered from the urine of a locally infected Corsican patient. Genetic analysis of both mitochondrial (cox1) and nuclear (internal transcribed spacer) DNA data from the Schistosoma eggs or miracidia recovered from the infected patients was conducted to elucidate the epidemiology of this outbreak.
  
  
  
  We identified two main infection foci along the Cavu River, with many Bulinus truncatus snails found in both locations. Of the 3544 snails recovered across all sites, none were naturally infected, but laboratory-based experimental infections confirmed their compatibility with the schistosomes isolated from patients. Molecular characterisation of 73 eggs or miracidia isolated from 12 patients showed infection with Schistosoma haematobium, S haematobium-Schistosoma bovis hybrids, and S bovis. Further sequence data analysis also showed that the Corsican schistosomes were closely related to those from Senegal in west Africa.
  
  
  
  The freshwater swimming pools of the Cavu River harbour many B truncatus snails, which are capable of transmitting S haematobium-group schistosomes. Our molecular data suggest that the parasites were imported into Corsica by individuals infected in west Africa, specifically Senegal. Hybridisation between S haematobium and the cattle schistosome S bovis had a putative role in this outbreak, showing how easily and rapidly urogenital schistosomiasis can be introduced and spread into novel areas where Bulinus snails are endemic, and how hybridisation could increase the colonisation potential of schistosomes. Furthermore our results show the potential risk of schistosomiasis outbreaks in other European areas, warranting close monitoring and surveillance of all potential transmission foci.
  
  
  
  WHO, ANSES, RICET, and the Ministry of Health and Consumption.
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France. Electronic address: boissier@univ-perp.fr.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Boissier
authors.affiliation: INRA, Laboratoire de recherches sur le développement de l'élevage, Corte, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Grech-Angelini
authors.affiliation: Department of Life Sciences, Parasites and Vectors Division, Natural History Museum, London, UK; London Centre for Neglected Tropical Disease Research, London, UK.
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Webster
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Allienne
authors.affiliation: Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium; Laboratory of Biodiversity and Evolutionary Genomics, Biology, University of Leuven, Leuven, Belgium.
authors.forename: Tine
authors.initials: T
authors.lastname: Huyse
authors.affiliation: Departamento de Parasitologia, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Mas-Coma
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Eve
authors.initials: E
authors.lastname: Toulza
authors.affiliation: OCIC, ECOTER, Office de l'Environnement de la Corse, Corte, France; Unité de suivi entomologique et de politique de lutte anti vectorielle, Agence régionale de santé de Corse, Ajaccio, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Barré-Cardi
authors.affiliation: Department of Life Sciences, Parasites and Vectors Division, Natural History Museum, London, UK; London Centre for Neglected Tropical Disease Research, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Kincaid-Smith
authors.affiliation: Parasitology Laboratory, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Salamanca, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Oleaga
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Galinier
authors.affiliation: Equipe parasites et écosystèmes méditerranéens, UMR 6134 CNRS SPE Science pour l'environnement, Université de Corse Pascal Paoli, Corte, France.
authors.forename: Joséphine
authors.initials: J
authors.lastname: Foata
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Rognon
authors.affiliation: Service de Parasitologie-Mycologie, CHU Toulouse and Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS UMR5282, Université de Toulouse, Toulouse, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Berry
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Mouahid
authors.affiliation: Hôpital Sainte Marguerite, Hopitaux Sud de Marseille, Marseille, France.
authors.forename: Rémy
authors.initials: R
authors.lastname: Henneron
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Moné
authors.affiliation: French Institute for Public Health Surveillance (Institut de Veille Sanitaire, InVS), Saint-Maurice, France.
authors.forename: Harold
authors.initials: H
authors.lastname: Noel
authors.affiliation: Université de Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Université de Montpellier, Perpignan, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Mitta
mesh_terms: D000818:Animals; D002033:Bulinus / Q000469:parasitology; D004196:Disease Outbreaks; D016021:Epidemiologic Studies; D005243:Feces / Q000469:parasitology; D005602:France / Q000453:epidemiology; D006801:Humans; D006824:Hybridization, Genetic; D012548:Schistosoma haematobium / Q000235:genetics / Q000302:isolation & purification*; D012553:Schistosomiasis haematobia / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission*; D012675:Senegal; D012908:Snails / Q000469:parasitology