title: Spatial distribution of Toxoplasma gondii oocysts in soil in a rural area: Influence of cats and land use.
abstract: Toxoplasma gondii is the protozoan parasite responsible for toxoplasmosis, one of the most prevalent zoonoses worldwide. T. gondii infects humans through the ingestion of meat containing bradyzoites or through soil, food or water contaminated with oocysts. Soil contamination with oocysts is increasingly recognized as a major source of infection for humans, but has rarely been quantified directly. In this study, we investigated the spatial pattern of soil contamination with T. gondii over an area of 2.25 km(2) in a rural area of eastern France. The frequency and spatial distribution of T. gondii in soil was analyzed in relation with the factors that could influence the pattern of contamination: cats' frequency and spatial distribution and land use. According to a stratified random sampling Scheme 243 soil samples were collected. The detection of T. gondii oocysts was performed using a recent sensitive method based on concentration and quantitative PCR. Sensitivity was improved by analyzing four replicates at each sampling point. T. gondii was detected in 29.2% of samples. Soil contamination decreased with increasing distance from the core areas of cat home ranges (households and farms). However, it remained high at the periphery of the study site, beyond the boundaries of the largest cat home ranges, and was not related to land use. This pattern of contamination strongly supports the role of inhabited areas which concentrate cat populations as sources of risk for oocyst-induced infection for both humans and animals. Moreover, soil contamination was not restricted to areas of high cat density suggesting a large spatial scale of environmental contamination, which could result from T. gondii oocysts dissemination through rain washing or other mechanisms.
authors.affiliation: Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Bâtiment Mendel, Université Lyon 1, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France; Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France; Université de Reims Champagne-Ardenne, CERFE, 08240 Boult-aux-bois, France. Electronic address: cecile.gotteland@gmail.com.
authors.forename: Cécile
authors.initials: C
authors.lastname: Gotteland
authors.affiliation: Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Bâtiment Mendel, Université Lyon 1, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France; Université de Lyon, VetAgro-Sup Campus Vétérinaire, 1 Avenue Bourgelat, F-69280 Marcy l'Etoile, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Gilot-Fromont
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Aubert
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France; Université de Reims Champagne-Ardenne, CERFE, 08240 Boult-aux-bois, France.
authors.forename: Marie-Lazarine
authors.initials: ML
authors.lastname: Poulle
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Dupuis
authors.affiliation: Université de Limoges, Laboratoire de Parasitologie-Mycologie, INSERM UMR 1094, 2 rue du Dr Marcland, 87025 Limoges, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Dardé
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France; Université de Reims Champagne-Ardenne, CERFE, 08240 Boult-aux-bois, France.
authors.forename: Marie-Amélie
authors.initials: MA
authors.lastname: Forin-Wiart
authors.affiliation: Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Bâtiment Mendel, Université Lyon 1, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France; Laboratoire Biostatistique-Santé, Service de Biostatistique, 162 Avenue Lacassagne, 69424 Lyon Cedex 03, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Rabilloud
authors.affiliation: Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, Bâtiment Mendel, Université Lyon 1, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France; Laboratoire Biostatistique-Santé, Service de Biostatistique, 162 Avenue Lacassagne, 69424 Lyon Cedex 03, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Riche
authors.affiliation: Université de Reims Champagne-Ardenne, Laboratoire de Parasitologie-Mycologie, EA 3800, UFR de Médecine, SFR Cap Santé FED 4231, 51 rue Cognacq-Jay, F-51096 Reims, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Villena
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D002415:Cats; D003710:Demography; D004787:Environmental Pollution; D005243:Feces / Q000469:parasitology; D005602:France / Q000453:epidemiology; D006801:Humans; D033661:Oocysts; D015995:Prevalence; D012987:Soil / Q000469:parasitology*; D014122:Toxoplasma / Q000235:genetics / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D014867:Water / Q000469:parasitology
chemical_list: D012987:Soil; D014867:Water
keywords: Domestic cat; Environmental contamination; Land use; Oocyst; Spatial distribution; Toxoplasma gondii