School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Ireland.
Vet Parasitol. 2011 Feb 10;175(3-4):287-92. doi: 10.1016/j.vetpar.2010.10.010. Epub 2010 Oct 29.
The population dynamics and prevalence of Fasciola hepatica in Galba truncatula were investigated on the Teagasc hill sheep farm in Country Mayo, Ireland from August 2006 until March 2008. Galba truncatula (n=974) were collected at fortnightly intervals in 4 snail habitats on the farm, their relative density and mean monthly rainfall and temperature were recorded. Snail abundance was associated with rainfall and temperature. G. truncatula abundance was generally low during winter 2006/2007 (December 2006-February 2007), mid spring and summer 2007 (April-July) and late autumn and winter 2007/2008 (October 2007-February 2008). Overall, two peaks in G. truncatula abundance were evident during the study period, an early spring (March) and late summer/autumn (late August-October) peak. Seasonal differences were observed in the prevalence of F. hepatica in G. truncatula, the greatest prevalence was evident in 2007 during the summer (25%) and autumn (16%). Two seasonal transmission peaks, as evident by the presence of mature infections in snails, one in summer/autumn and the other in late winter/early spring. Not unsurprising, cercariae (28%) and rediae (29%) were the predominant developmental stages observed in mature and pre-adult snails respectively. Worthy of note in this study, cercariae were also evident in pre-adult snails. The present study highlights the influence of milder temperatures and wetter conditions on both snail and fluke development. If the trend in mild and wet weather conditions continues, there is the potential for an increase in the number of G. truncatula habitats and ultimately the prevalence of fasciolosis in grazing livestock in Ireland.
2006 年 8 月至 2008 年 3 月，在爱尔兰梅奥郡的 Teagasc 山地绵羊农场，我们调查了肝片吸虫在圆扁蜷（Galba truncatula）体内的种群动态和流行情况。每隔两周，我们在农场的 4 个螺栖息地收集圆扁蜷（n=974），记录它们的相对密度以及每月的平均降雨量和温度。螺的丰度与降雨量和温度有关。2006/2007 年冬季（2006 年 12 月至 2007 年 2 月）、早春和夏季（2007 年 4 月至 7 月）以及晚秋和冬季（2007/2008 年 10 月至 2008 年 2 月），圆扁蜷的数量普遍较低。总体而言，在研究期间，圆扁蜷的数量有两个高峰期，一个是早春（3 月），另一个是夏末/秋季（8 月底至 10 月）。在圆扁蜷体内，肝片吸虫的流行情况存在季节性差异，2007 年夏季（25%）和秋季（16%）的流行率最高。两个季节性传播高峰，即通过螺体内成熟感染的存在而明显，一个高峰在夏季/秋季，另一个高峰在冬末/早春。不出所料，尾蚴（28%）和雷蚴（29%）是成熟和幼螺中分别观察到的主要发育阶段。值得注意的是，在本研究中，尾蚴也存在于幼螺中。本研究强调了温和的温度和潮湿条件对螺和吸虫发育的影响。如果温和湿润天气的趋势持续下去，那么爱尔兰放牧牲畜中圆扁蜷栖息地的数量以及肝片吸虫病的流行率有可能增加。
