The epidemiology of the parasites Giardia, Cryptosporidium and Entamoeba - The wastewater discharge nexus.

目前正在调查易北河和莱茵河中三种重要寄生虫的原因和分布。虽然水媒介吸引了大量的研究工作，但这些危及生命的微生物的水媒传播仍然构成严重的公共卫生风险。在正在进行的调查中，使用微生物学和分子技术分析了97种多形蚌和河蚌的原生动物寄生虫的存在。在检出的贻贝样本中，53%的溶组织大肠杆菌和30%的贾第鞭毛虫中检出隐孢子虫。因此，越来越多的证据支持污水处理厂（WWTPs）排放与河道中原生动物寄生虫的发生和分布之间存在联系。这种“联系”是本次调查的重点。到目前为止，研究只能对污水处理厂对水体和娱乐场所的微生物污染的贡献提供部分答案，强调需要显著扩展已知的流行病学方法并将其作为生物监测工具加以利用。这项工作的目的主要有两个方面：1)建立废水排放与寄生虫传播之间的联系；2)促进基础研究工作，使人们能够正确理解这些生物体的动态，这对于制定预防疾病暴发的战略至关重要。在流行病学研究中，重要的是要考虑到所有可能干扰生物学结果的因素。众所周知，寄生和疾病动力学受到环境条件的强烈影响。温度、营养和盐度等因素对贻贝-原生动物相互作用和病原体最终传播的影响需要进行调查，因为波动可能对疾病暴发产生深远影响。这项工作的第一阶段以莱茵河为目标，产生了有趣的数据，需要通过原始项目计划中预见的复制工作进行验证和验证。因此，下一阶段的工作将包括对易北河进行密集采样，并分析汉堡污水处理厂的原始数据。这项研究将对这三种病原体的流行病学有一个完整的了解。它们是如何进入环境、侵入和传播的。这项研究将为了解原生动物疾病如何从个体扩大到群体和社区提供线索。此外，研究结果将有助于开发一种有效的工具，以贻贝为选择的生物模型，用于水体的卫生生物监测。此外，调查结果将与卫生部传染病控制司有关，该司为保护公众健康制定了病原体的水质标准。

Work is on-going to investigate the causes and distribution of three important parasites: in the Elbe and Rhine rivers. Whereas the water medium has attracted considerable research efforts, waterborne transmission of these life-threatening microorganisms still constitutes a serious public health risk. In the on-going investigation, 97 mussels of Dreissena polymorpha and Corbicula fluminea have been analysed for the presence of protozoan parasites using microbiological and molecular techniques. Cryptosporidium spp have been detected in 53% E. histolytica in 30% Giardia spp in 48% of the mussels sample examined. Thus evidence is accumulating in support of a link between wastewater treatment plants (WWTPs) discharge and the occurrence and distribution of protozoan parasites in river courses. This ‘nexus’ is the focus of this investigation. Up to now, research has only been able to provide partial answers to the contribution of WWTPs to microbial pollution of water bodies and recreational sites, underscoring the need for a significant expansion of known epidemiological approaches and their harnessing as bio-monitoring tools. The purpose of this work is mainly two-fold: 1) to establish the link between the wastewater discharges and the spread of parasites; 2) to catalyze basic research effort that enables a correct understanding of the dynamics of these organisms, which is vital for the development of prevention strategies against disease outbreaks.In epidemiological studies, it is important to take into account all factors that could interfere with biological results. Parasitism and disease dynamics are known to be strongly influenced by environmental conditions. Effects of factors such as temperature, nutrients and salinity on the mussel-protozoa interaction and the ultimate transmission of the pathogens need to be investigated as fluctuations can have far-reaching implications on disease outbreaks.The first phase of this work which targeted the Rhine river has generated interesting data that needs to be verified and validated through replicated work as foreseen in the original project plan. Thus the next phase in the work will involve an intensive sampling of the Elbe river and analysis of raw data from Hamburg WWTPs.This study will generate a complete understanding of the epidemiology of the three pathogens. How they: enter the environment, invade and are transmitted. The study will provide leads as to how protozoa diseases scale up from individuals to populations and communities. Furthermore, findings of the study will contribute to on-going efforts to develop an effective tool, with Mussel as the choice biological model, for sanitary biomonitoring of water bodies. In addition, findings will have relevance to the Ministry of Health’s department of infectious disease control, which establishes water-quality standards for pathogens to protect public health.