Raoul F, Deplazes P, Nonaka N, Piarroux R, Vuitton D A, Giraudoux P
Department of Biology and Ecophysiology, Institute for Environmental Sciences and Technology, WHO Collaborating Centre for Prevention and Treatment of Human Echinococcoses, University of Franche-Comte, Besançon, France.
Int J Parasitol. 2001 Dec;31(14):1579-88. doi: 10.1016/s0020-7519(01)00280-6.
The aim of this study was to estimate the relevance of Echinococcus multilocularis coproantigen detection in fox faeces collected in the field to identify different levels of endemicity for Echinococcus multilocularis on a large scale (n x 10 km(2)). Six study sites were selected in a high endemicity area and two study sites in a low endemicity area in eastern France on the basis of landscape composition. Sampling was undertaken in the winters of 1996-97, 1997-98 and 1998-99. At each site, (i) necropsy and intestine examination was undertaken on a sample of shot foxes (total number of foxes, 222), and (ii) fox faeces were collected in the field along road verges, and scored for degradation status (total number of faeces, 625). Fox faeces were also sampled in a control area (n=30) in western France in the summer of 1998. Intestines were examined according to the sedimentation method. Echinococcus multilocularis coproantigens were detected by using two ELISA tests: EM-ELISA and EmA9-ELISA. The necropsy prevalence in high and low endemicity areas was 63.3% and 19.4%, respectively, and the distribution of adult worms in the fox population was highly overdispersed (75.5% of the total biomass was harboured by 11.6% of foxes). Using the two ELISA tests, there was no difference in the detection of E. multilocularis coproantigens in field faeces, regardless of the degradation status. The medians of EM- and EmA9-ELISA OD values of field faeces in high endemicity area were significantly higher than in low endemicity area (P<0.001 for both ELISA). The distribution of EM-ELISA OD values in low endemicity area was significantly higher (P=0.002) than in the control area. Moreover, for the two ELISA, the observed ELISA OD value distributions in high endemicity area, low endemicity area and control area seemed representative of the distribution of adult worms in fox populations. These results indicate that E. multilocularis coproantigen detection in field faeces could serve for large-scale surveillance, as an alternative to necropsy.
本研究的目的是评估在野外收集的狐狸粪便中检测多房棘球绦虫粪抗原，对于大规模（n×10 km²）确定多房棘球绦虫不同流行程度的相关性。基于景观构成，在法国东部的一个高流行区选择了6个研究地点，在一个低流行区选择了2个研究地点。在1996 - 1997年、1997 - 1998年和1998 - 1999年冬季进行采样。在每个地点，（i）对一部分被射杀狐狸（狐狸总数为222只）进行尸检和肠道检查，（ii）沿着路边在野外收集狐狸粪便，并对其降解状态进行评分（粪便总数为625份）。1998年夏季，还在法国西部的一个对照区采集了狐狸粪便样本（n = 30）。按照沉淀法检查肠道。使用两种酶联免疫吸附测定（ELISA）试验检测多房棘球绦虫粪抗原：EM - ELISA和EmA9 - ELISA。高流行区和低流行区的尸检患病率分别为63.3%和19.4%，狐狸种群中成虫的分布高度过度分散（11.6%的狐狸携带了75.5%的总虫体生物量）。使用这两种ELISA试验，无论粪便降解状态如何，野外粪便中多房棘球绦虫粪抗原的检测结果没有差异。高流行区野外粪便的EM - ELISA和EmA9 - ELISA光密度（OD）值中位数显著高于低流行区（两种ELISA均P < 0.001）。低流行区EM - ELISA OD值的分布显著高于对照区（P = 0.002）。此外，对于这两种ELISA，在高流行区、低流行区和对照区观察到的ELISA OD值分布似乎代表了狐狸种群中成虫的分布情况。这些结果表明，野外粪便中多房棘球绦虫粪抗原检测可作为尸检的替代方法，用于大规模监测。
