水体中隐孢子虫卵囊的检出及其活力分析

从水中检测隐孢子虫卵囊是评价水源传播人类隐孢子虫病风险的第一步，从水中检出的卵囊的活力需要进行测定才能估计水源爆发的真正风险，应用聚丙烯盒式过滤器和美国环保局（USEPA）1622过滤方法的囊式过滤器（Gelman,Michigan,USA)，分别过滤了当地（法国鲁昂）的环境水和供给水，并用免疫磁分离技术（IMS）进行分离。用免疫荧光检测法（IFA）从浓缩的水样中检测到了隐孢子虫卵囊。环境水中的卵囊浓度是每升水中0.12-2.7个卵囊；供给水中的卵囊浓度是每升水中0.03-0.06个卵囊，用新生小鼠模型初步评价了检出卵囊的感染力。结果证明了隐孢子虫卵囊在环境中尤其是水中的广泛分布；同时表明，评估水源传播的隐孢子虫病的风险时，不仅要从水中检出卵囊，而且要测定检出的卵囊的活力。表1参22。

DETECTION OF CRYPTOSPORIDIUM OOCYSTS FROM WATERS AND VIABILITY ASSAY

Detection of Cryptosporidium spp. oocysts from waters is the first step for the evaluation of the risk of waterborne cryptosporidiosis for human. Viability of oocysts isolated from waters must be evaluated to estimate a real risk of waterborne outbreaks. Using polypropylene cartridge filters and the capsule filters (Gelman, Michigan, USA) of the US EPA (Environmental Protection Agency) 1622 filtration method, local environmental waters and distribution waters from the city of Rouen, France were filtered respectively following by immunomagnetic separation (IMS). Cryptosporidium oocysts were detected in the concentrated water samples by IFA (Immunofluorescence assay). The densities of oocysts were 0.12~2.7 oocysts per liter for the environmental waters and 0.03~0.06 oocysts per liter for the distribution waters. Infectivity of the obtained oocysts was evaluated by a neonatal mice model. Results proved the wide distributions of Cryptosporidum oocysts in the environment especially in waters, and indicated that not only detection of oocysts from waters but also viability of oocysts should be considered for the evaluation of the risk of waterborne human cryptosporidiosis.