Spatial distribution of Toxoplasma gondii oocysts in soil in a rural area: Influence of cats and land use
Spatial distribution of Toxoplasma gondii oocysts in soil in a rural area: Influence of cats and land use
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DOI：
10.1016/j.vetpar.2014.08.003
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发表时间：
2014-10-15
影响因子：
2.6
通讯作者：
Villena, Isabelle
中科院分区：
文献类型：
--
作者：
Gotteland, Cecile;Gilot-Fromont, Emmanuelle;Villena, Isabelle
弓形虫病是世界上最流行的人畜共患病之一，由弓形虫引起。T.弓形虫通过摄入含有缓殖子的肉类或通过被卵囊污染的土壤，食物或水感染人类。越来越多的人认识到卵囊污染土壤是人类感染的主要来源，但很少直接量化。本文研究了土壤中T.在法国东部的一个农村地区，在2.25公里（2）的面积上发现了一种弓形虫。本文报道了该虫的频率和空间分布。分析了土壤中弓形虫与影响污染格局的因素：猫的频率和空间分布以及土地利用的关系。根据分层随机抽样方案，收集了243个土壤样品。T.使用基于浓度和定量PCR的最新敏感方法进行弓形虫卵囊。通过在每个采样点分析四次重复来提高灵敏度。T.弓形虫检出率为29.2%。土壤污染随着距离猫的活动范围（家庭和农场）的核心区域的距离增加而减少。然而，它仍然很高，在研究地点的外围，超出了最大的猫的家园范围的边界，并没有涉及到土地使用。这种污染模式有力地支持了集中猫种群的居住区作为卵囊诱导的人类和动物感染的风险来源的作用。此外，土壤污染并不局限于猫密度高的地区，这表明环境污染的空间尺度很大，这可能是由T。弓形虫卵囊通过雨水冲刷或其他机制传播。(C)2014爱思唯尔有限公司版权所有。
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. (C) 2014 Elsevier B.V. All rights reserved.