Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Ave., St. Paul, MN, 55108, USA.
Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Parasitol Res. 2024 Aug 15;123(8):300. doi: 10.1007/s00436-024-08319-6.
Fasciolosis, caused by the liver fluke Fasciola spp., is a significant parasitic disease of livestock and humans worldwide. Fasciola transmission and life cycle are highly dependent on climatic conditions, especially temperature and humidity. This dependency has gained significance in the context of ongoing climate change. This literature review examined evidence on the effects of temperature variability on the developmental stages of Fasciola spp. and the snail intermediate hosts. We reviewed free larval stages of Fasciola spp. development, as well as snail intermediate hosts, while investigating the climate-related factors influencing each stage. We found that Fasciola spp. egg hatching and development were inhibited below 10 °C and optimal between 20 and 30 °C, miracidia hatching time decreased with higher temperatures and cercarial shedding by snail hosts accelerated around 27 °C. Further, metacercarial viability declined at higher temperatures but was prolonged by higher humidity. Snail intermediate host growth rates peaked at 25 °C, and their susceptibility to Fasciola infection depends on temperature, underscoring its importance in transmission dynamics. Overall, the Fasciola life cycle and snail host development exhibit stage-specific temperature thresholds, indicating a complex relationship between temperature fluctuations and parasite transmission potential. This research highlights the key role of temperature and humidity on Fasciola spp. and snail development, shedding light on the potential consequences of climate change on their survival, development, and disease transmission. Data limitations, primarily from the scarcity of high-resolution climate-related experiments, should drive future research to enhance predictive models and deepen our understanding of the impact of climate change on this parasitic disease.
片形吸虫病是由片形科肝片吸虫引起的一种重要的人畜寄生虫病，在全球范围内广泛存在。片形吸虫的传播和生命周期高度依赖于气候条件，尤其是温度和湿度。在当前气候变化的背景下，这种依赖性变得尤为重要。本文献综述探讨了温度变化对片形科吸虫各发育阶段和中间螺宿主的影响。我们调查了影响每个阶段的气候相关因素，同时研究了片形科自由幼虫阶段的发育以及中间螺宿主。我们发现，片形科吸虫卵的孵化和发育在 10°C 以下受到抑制，在 20-30°C 之间最佳，毛蚴孵化时间随温度升高而缩短，而螺宿主的尾蚴脱落则在 27°C 左右加速。此外，囊蚴的生存能力随温度升高而下降，但湿度升高可延长其存活时间。中间螺宿主的生长速度在 25°C 时达到峰值，其对片形吸虫感染的易感性取决于温度，这突显了温度在传播动力学中的重要性。总的来说，片形吸虫的生命周期和中间螺宿主的发育表现出特定阶段的温度阈值，表明温度波动与寄生虫传播潜力之间存在复杂的关系。这项研究强调了温度和湿度对片形科吸虫和螺宿主发育的关键作用，揭示了气候变化对其生存、发育和疾病传播的潜在影响。数据的局限性，主要是由于缺乏与气候相关的高分辨率实验，应推动未来的研究，以增强预测模型并加深我们对气候变化对这种寄生虫病影响的理解。
