Cryptosporidium movement in water: impact of eutrophication and climate change on the zoonotic disease agent

该项目将是第一个跟踪隐孢子虫卵囊进入威尔士河岸生态系统水生食物链的命运。隐孢子虫是一种直到20世纪70年代中期才被发现的人类病原体; 1993年，密尔沃基有40万人在水处理失败后感染，从那时起，整个发达国家的大规模爆发（最近的瑞典，2010年）使寄生虫一直处于公众的视线中。受感染的宿主每天释放多达109个卵囊，发现单个卵囊会迫使关闭和失去饮用水供应（例如，2015年英格兰西北部，30万家庭受到影响）。在威尔士农村地区，不同的污染源尚不清楚，但很可能来自农村社区的养羊业。这些多重污染源很难诊断和监测，而且由于复杂方法的成本，几乎不可能消除。与感染剂量相比，卵囊的大量过量生产（只有10个卵囊可以开始感染）表明，在自然环境中，大多数卵囊被生物去除，可能是通过放牧和悬浮喂养无脊椎动物和原生生物。这些相互作用可能受到富营养化（与土地使用和气候变化有关）的不利影响，增加了隐孢子虫在发展中国家和发达国家“蓝色大理石”情况下的重要性。

This project will be the first to follow the fate of Cryptosporidium oocysts as they enter aquatic food chains in Welsh riparian ecosystems. Cryptosporidium is a human pathogen unknown until the mid-1970s; in 1993 0.4 million people were infected in Milwaukee following a water treatment failure, and since then, large outbreaks throughout the developed world (most recently Sweden, 2010) have kept the parasite in the public eye. Infected hosts release up to 109 oocysts per day, and the discovery of a single oocyst forces closure and loss of drinking water supplies (e.g. NW England 2015, 0.3 million homes affected). In rural Wales, the different sources of contamination are unknown, but are likely to arise from sheep farming in rural communities. These multiple sources of contamination are difficult to diagnose and monitor, and almost impossible to eliminate due to costs of complex methodologies. The huge excess production of oocysts compared to the infective dose (only 10 oocysts can start an infection) suggests that in the natural environment, most oocysts are removed biotically, probably by grazing and suspension feeding invertebrates and protists. These interactions may be adversely affected by eutrophication (connected with land use and climate change), increasing the importance of Cryptosporidium in both the developing world and in 'Blue Marble' situations within the developed world.