Issia Laura, Pietrokovsky Silvia, Sousa-Figueiredo José, Stothard J Russell, Wisnivesky-Colli Cristina
Unidad de Ecología de Reservorios y Vectores de Parásitos, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, C1428EHA Buenos Aires, Argentina.
Vet Parasitol. 2009 Nov 12;165(3-4):341-4. doi: 10.1016/j.vetpar.2009.07.011. Epub 2009 Jul 15.
Between autumn and spring 2006, a coprological survey was performed in two wildlife reserves located in the north of Argentine Patagonia to determine the prevalence of Fasciola hepatica and the number of parasite eggs per gram (epg) of feces in wild guanacos (Lama guanicoe), coypus (Myocastor coypus), and locally born and raised goats and sheep. Snails of the Family Lymnaeidae were collected in freshwater habitats, identified taxonomically and analyzed parasitologically. Prevalence of patent infection was 100% in sheep (n=69) and coypus (n=9), 84% in goats (n=20) and 0.5% in guanacos (n=224). No significant differences in epg were found among animals, but the median epg of coypus (160) and sheep (160) was higher than that of goats (80). For guanacos and goats, a negative binomial model estimating the population egg-count frequency could be fitted, while for coypus and sheep parasite egg-count frequencies trended toward a normal distribution, indicative of a more even, and much less aggregated distribution across sampled hosts. All snails (n=175) were Lymnaea truncatula and none of them was found infected. This is the first report of fascioliasis in free-ranging guanacos in Argentina. Coypu appears to be a major wildlife reservoir of F. hepatica, which was presumably introduced locally by livestock.
2006年秋至2007年春期间，在阿根廷巴塔哥尼亚北部的两个野生动物保护区开展了一项粪便学调查，以确定野生原驼（骆马属）、河狸鼠（河狸鼠属）以及当地出生并饲养的山羊和绵羊体内肝片吸虫的感染率及每克粪便中的寄生虫卵数（epg）。在淡水生境中采集椎实螺科的螺类，进行分类鉴定和寄生虫学分析。绵羊（n = 69）和河狸鼠（n = 9）的显性感染率为100%，山羊（n = 20）为84%，原驼（n = 224）为0.5%。动物之间的epg未发现显著差异，但河狸鼠（160）和绵羊（160）的epg中位数高于山羊（80）。对于原驼和山羊，可以拟合一个估计总体虫卵计数频率的负二项式模型，而对于河狸鼠和绵羊，寄生虫卵计数频率呈正态分布趋势，表明在抽样宿主中的分布更均匀且聚集程度更低。所有采集的螺类（n = 175）均为截形椎实螺，未发现感染情况。这是阿根廷野生原驼肝片吸虫病的首次报告。河狸鼠似乎是肝片吸虫的主要野生动物宿主，推测是由家畜在当地引入的。
