Laboratório de Biologia Parasitária, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Agent-Based Modelling Laboratory, York University, Toronto, ON, Canada.
Parasitology. 2022 Jul;149(8):1078-1084. doi: 10.1017/S0031182022000579. Epub 2022 May 16.
is the main causative agent of intestinal schistosomiasis which affects millions of people worldwide. At the larval stage, miracidia are released into bodies of water where they utilize their motility to successfully infect their intermediate host, snails. Here, we revisit the motility and survival of miracidia throughout its life span. Briefly, miracidia motility was monitored at 30-min and 60-min intervals under the presence/absence of natural/artificial light. Based on a subjective evaluation of activity, body shape and transparency, 6 categories of miracidia activity were established from its fully active stage to its immobile larva stage. The estimated life span of miracidia was 5.8 and 3.5 h in the experiments with 60-min and 30-min observation intervals, respectively. Death was defined by an absence of cilia and body movement. When mobility was used as a proxy for infectivity, infective miracidia were detected at 2.5 and 4.5 h, respectively. The present miracidia motility and survival re-evaluation supports parameters optimization for computational modelling of schistosomiasis transmission dynamics. Target control interventions, especially at late stages next to transmission interruption, may greatly benefit from improved modelling studies.
血吸虫是世界范围内数百万人感染的肠道血吸虫病的主要病原体。在幼虫阶段，尾蚴被释放到水体中，利用其运动成功感染其中间宿主——蜗牛。在这里，我们重新审视了尾蚴在其整个生命周期中的运动和存活情况。简要地说，在自然光和人工光的存在/不存在的情况下，每隔 30 分钟和 60 分钟监测尾蚴的运动。根据对活动、体型和透明度的主观评估，将尾蚴从完全活跃阶段到不动幼虫阶段分为 6 个活动类别。在观察间隔分别为 60 分钟和 30 分钟的实验中，尾蚴的估计寿命分别为 5.8 和 3.5 小时。死亡的定义是纤毛和身体运动的缺失。当运动被用作感染力的替代指标时，分别在 2.5 和 4.5 小时检测到感染性尾蚴。本研究重新评估了尾蚴的运动和存活情况，为血吸虫病传播动力学的计算模型优化提供了参数。目标控制干预措施，特别是在传播中断后的后期阶段，可能会极大地受益于改进的建模研究。
