Gotteland Cécile, Aubert Dominique, Gibert Philippe, Moinet Marie, Klein François, Game Yvette, Villena Isabelle, Gilot-Fromont Emmanuelle
1 Université de Lyon , Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France .
Vector Borne Zoonotic Dis. 2014 Jun;14(6):403-13. doi: 10.1089/vbz.2013.1304. Epub 2014 Apr 18.
Toxoplasmosis is characterized by a complex epidemiology. The risk of infection for humans depends on their contact with infective oocysts in a contaminated environment and on the amount of tissue cysts located within consumed meat. Unfortunately, the prevalence of tissue cysts is largely unknown for game species. Although herbivorous game species are a source of infection for humans, the level of infection found in wildlife can also be used to estimate environmental contamination. The aim of this study was to estimate the prevalence of Toxoplasma gondii infection and analyze its temporal dynamics in one population of chamois (Rupicapra rupicapra), one of mouflon (Ovis gmelini musimon), and two of roe deer (Capreolus capreolus) in France, surveyed during a period of 6 to 28 years. Taking into account individual risk factors, we specifically analyzed the relationship between T. gondii prevalence and meteorological conditions that may influence oocyst survival. Serum samples from 101 chamois, 143 mouflons, and 1155 roe deer were tested for antibodies against T. gondii using the modified agglutination test (MAT), an enzyme-linked immunosorbent assay (ELISA) assay, or both. Using MAT with a threshold of 1:6, seroprevalence was 14.7% in mouflon, 16.8% in chamois, and 43.7% in roe deer. In mouflon and roe deer, seroprevalence was positively correlated with age and/or body mass, in accordance with the hypothesis that antibodies have long-term persistence. In roe deer, seropositivity differed between the two populations and changed linearly over time between 1983 and 2010, increasing by a factor 1.75 every 10 years. Moreover, in this species, the highest prevalences were found during dry and cold years or during warm and moist years, depending on the population. Our results suggest that the risk for people to acquire infection through game meat increases over time, but with high variability according to the population of origin and meteorological conditions of the year.
弓形虫病具有复杂的流行病学特征。人类的感染风险取决于他们在受污染环境中与感染性卵囊的接触情况，以及食用肉类中所含组织包囊的数量。遗憾的是，野生动物物种中组织包囊的流行情况很大程度上尚不清楚。虽然食草野生动物物种是人类的感染源，但在野生动物中发现的感染水平也可用于估计环境污染情况。本研究的目的是估计法国一个岩羚羊（岩羚羊属）种群、一个摩弗伦羊（欧洲盘羊摩弗伦亚种）种群和两个狍（狍属）种群中弓形虫感染的流行率，并分析其时间动态，调查时间为6至28年。考虑到个体风险因素，我们特别分析了弓形虫流行率与可能影响卵囊存活的气象条件之间的关系。使用改良凝集试验（MAT）、酶联免疫吸附测定（ELISA）或两者对101只岩羚羊、143只摩弗伦羊和1155只狍的血清样本进行了抗弓形虫抗体检测。使用MAT且阈值为1:6时，摩弗伦羊的血清阳性率为14.7%，岩羚羊为16.8%，狍为43.7%。在摩弗伦羊和狍中，血清阳性率与年龄和/或体重呈正相关，这与抗体具有长期持续性的假设一致。在狍中，两个种群的血清阳性率不同，且在1983年至2010年期间随时间呈线性变化，每10年增加1.75倍。此外，在该物种中，根据种群不同，在干燥寒冷年份或温暖湿润年份发现的流行率最高。我们的结果表明，人们通过食用野味感染的风险随时间增加，但根据来源种群和当年的气象条件存在很大差异。
