Identifying Environmental Factors for Soil Transmitted and Food Borne Helminth Diseases in Border Regions of Northern Thailand

人类寄生虫感染（蠕虫病）损害健康和农业生产力，对泰国等中低收入国家产生重大影响。特别是在整个东南亚，城市地区的扩张和来自公共卫生项目不发达国家的人口流动增加了疾病的传播。本项目将调查环境对蠕虫病传播的影响。许多新出现的蠕虫病通过人与动物之间接触的增加、粮食生产系统的集约化和一体化以及迁移范围的扩大与环境有关。因此，有效控制和治疗许多蠕虫疾病将受益于更好地将临床、兽医和农业组成部分纳入环境驱动的研究战略。泰国被列为“中高收入”国家。然而，由于寄生虫病的性质，流行地点受到包括柬埔寨、老挝和缅甸在内的边境国家的严重影响，这些国家都被列为“最不发达”国家。我们的研究小组最近利用高度敏感的分子诊断法确定了泰国三个边境地区的基线人类感染率。过去在泰国等社区对蠕虫感染的低估以及我们以前在菲律宾的工作为政府政策的制定提供了不完整的信息。拟议的项目将利用已经建立的人类流行数据[3]，重点关注泰国北部流行地区的特定地点和寄生虫种类，以便确定疾病传播的环境因素。其中一类寄生虫，土壤传播蠕虫（STH），需要严重的环境污染才能有效传播疾病。约有15亿或四分之一的世界人口感染了STH，包括主要种类的蛔虫、鞭虫和钩虫。在土壤或未清洗的蔬菜中发现的寄生虫卵是感染的主要来源。同样，食源性疾病，包括致癌的Opisthorchis，是通过食用未煮熟的鱼而感染的，并且与水源以及蜗牛和鱼宿主之间的相互作用有关。该学生将在泰国花费大量时间，收集土壤、蔬菜和水生样本，使用传统的显微镜和最近开发的分子分析进行诊断。将使用空间模型（GIS地理信息系统）对疾病的环境焦点进行分层，以展示食物和地理在寄生虫疾病传播中的重要性。地球观测数据将用于建立气候和其他相关环境因素的地理信息系统层，并使干预战略能够根据未来可能的变化进行评估。确定疾病传播的环境因素将有助于建立预测模型，以便更好地制定明智的政府控制政策。[10]张建军，张建军，张建军，张建军。中国外来人畜共患寄生虫感染的研究进展。中华寄生虫病杂志，2016,31 (1):391 -397Gordon CA, McManus DP, Acosta LP, Olveda RM, Williams GM, Ross AG, Gray DJ， Gobert GN：多重实时PCR监测人类肠道蠕虫揭示了菲律宾北萨马岛广泛存在的多寄生现象。中华寄生虫病杂志，2015,45(7):477-483Adisakwattana P, Yoonuan T, Phuphisut O, Poodeepiyasawat A, Homsuwan N, Gordon CA, McManus DP, Atkinson LE, Mousley A， Gobert GN：使用qPCR诊断与传统显微镜方法相结合，泰国边境地区临床蠕虫病的患病率升高。中国寄生虫病杂志，2020,13(1):416。

Parasitic worm infections (helminthiases) of humans greatly impact low to medium income countries such as Thailand, by undermining health and agricultural productivity. Particularly across Southeast Asia, the expansion of urban areas and the movement of people from countries with less developed public health programs, have increased disease transmission. This project will investigate environmental influences on helminth disease transmission. Many emerging helminthiases are linked to the environment through increased contact between humans and animals, the intensification and integration of food production systems, and the expansion of migration [1]. Therefore, effective control and treatment of many helminth diseases would benefit from better integration of clinical, veterinary and agricultural components embedded in an environmentally-driven research strategy.Thailand is classified as an 'Upper Middle Income' Country. However due the nature of helminth diseases endemic sites are significantly impacted by border countries including Cambodia, Laos and Myanmar, all of which are classified as 'Least Developed' Countries. Our research team has recently established baseline human infection rates in three Thailand border regions, using highly sensitive molecular diagnostics. In the past the under-estimation of helminth infections in communities such as Thailand and our previous work in the Philippines [2], provides incomplete information for the development of government policy.The proposed project will use already established human prevalence data [3] to focus on specific locations and parasite species in endemic regions of Northern Thailand, so that environmental components of disease transmission can be identified. One class of parasites, soil transmitted helminths (STH), requires significant environmental contamination for effective disease transmission. Approximately 1.5 billion or quater of the world's population are infected by STH, including the main species of Ascaris, Trichuris and hookworm. Parasite eggs found in the soil or unwashed vegetables are the primary source of infection. Similarly, food borne diseases, including the cancer-causing Opisthorchis, are contracted by consuming uncooked fish, and are linked to water sources, and the interaction between snail and fish hosts. The student will spend considerable time in Thailand, collecting soil, vegetable and aquatic samples for diagnostics using traditional microscopy and more recently developed molecular analysis. Environmental foci of disease will be stratified using spatial modelling (GIS geographical information system) to demonstrating the importance of food and geography, in helminth disease transmission. Earth observation data will be used to build GIS layers of climatic and other relevant environmental factors, and enable intervention strategies to be assessed against likely future changes. Identification of environmental components of disease transmission will lead to predictive models for better informed government control policies. [1] Gordon CA, McManus DP, Jones MK, Gray DJ, Gobert GN: The Increase of Exotic Zoonotic Helminth Infections: The Impact of Urbanization, Climate Change and Globalization. Adv Parasitol 2016, 91:311-397.[2] Gordon CA, McManus DP, Acosta LP, Olveda RM, Williams GM, Ross AG, Gray DJ, Gobert GN: Multiplex real-time PCR monitoring of intestinal helminths in humans reveals widespread polyparasitism in Northern Samar, the Philippines. Int J Parasitol 2015, 45(7):477-483.[3] Adisakwattana P, Yoonuan T, Phuphisut O, Poodeepiyasawat A, Homsuwan N, Gordon CA, McManus DP, Atkinson LE, Mousley A, Gobert GN: Clinical helminthiases in Thailand border regions show elevated prevalence levels using qPCR diagnostics combined with traditional microscopic methods. Parasit Vectors 2020, 13(1):416.