Spatial clustering pre and post-treatment for schistosomiasis and geohelminths

描述（由申请人提供）：本项目的最终目标是确定不同因素在血吸虫病和土传蠕虫（STH）感染和再感染中的相对作用，以改善目前控制这些寄生虫的策略。血吸虫病和性病是广泛的寄生虫感染，对社会经济发展造成巨大损失。估计有20亿人受到这些寄生虫的影响。研究多重感染的程度以及它们在感染易感性和疾病结局方面对彼此的影响，对于考虑联合使用化疗和疫苗接种的控制计划非常重要。由于可用于控制的资源往往是有限的，因此必须了解血吸虫病在微观水平上的分布，以针对高危人群制定最佳干预策略。我们相信，空间的方法可以导致识别宿主的遗传，免疫和行为特征，环境和其他因素，决定感染和疾病在人群中的模式之间的复杂的相互作用。因此，本研究拟检验三个基本假设：1）S. PZQ和阿苯达唑治疗后曼氏和STH感染和再感染不是随机的，而是在个人、家庭和社区水平上的异质性; 2）上述寄生虫的空间分布与人口统计学、免疫学、遗传学社会经济和人类行为参数和3）治疗计划将对位于距离潜在传播地点不同距离的群体和家庭产生不同的影响，具有不同的传输潜力。治疗计划后的地理空间感染集群将与感染前的集群显著不同。在检验这些假设的过程中，我们将比较治疗前和治疗后一年的个人和家庭层面蠕虫的空间分布，并与我们已经掌握的流行率、感染强度、人口统计学、社会经济学、水接触模式、遗传和免疫因素等数据进行分析。我们还将使用相同的方法在第二次治疗后2年收集与这些变量相关的数据。在这项试点研究中使用的方法，包括多寄生虫感染和化疗干预再感染的建模工作，可能会在其他农村地区进行测试。

DESCRIPTION (provided by applicant): This project has the ultimate goal of determining the relative contribution of different factors in infection and reinfection of schistosomiasis and soil transmitted helminths (STH) to improve current strategies for control of these parasites. Schistosomiasis and STH are widespread parasitic infections posing an enormous toll on the socioeconomic development. An estimated 2 billion people are affected by those parasites. Studies of the extent of multiple infections and the impact they have on each other in terms of both susceptibility to infection and disease outcomes are important for control programs that consider the use of chemotherapy and vaccination jointly. As resources available for control are often limited, it is essential to know the distribution of schistosomiasis at the micro-level to devise optimal intervention strategies for targeting high- risk population. We believe that a spatial approach can lead to identification of complex interactions among host genetic, immunological, and behavioral characteristics, the environment, and other factors that determine the pattern of infection and disease in human populations. Therefore the proposed project will test 3 general hypothesis: 1 )that spatial distributions of S. mansoni and STHs infections and reinfection following PZQ and albendazol treatment are not random but heterogeneous at the individual, household and community levels; 2)that spatial distribution of the above parasites is associated with demographic, immunological, genetic, socioeconomic and human behavior parameters and 3)that the treatment program will have a varying impact across groups and households located at different distances from potential transmission sites and from sited with different transmission potential. The geospatial clusters of infection after the treatment program will be significantly different from the pre-infection clusters. In the process of testing these hypothesis we will compare the spatial distribution of helminths individually and at households evels before treatment and one year after treatment and analyzed with data we already have of prevalence, ntensity of infection, demographic, socioeconomic, water contact patterns, genetic and immunological actors. We will also collect data related to those variables 2 years after the second treatment using the same methods. The approach used in this pilot study, including modeling efforts of multi-parasite infection and re-infection with a chemotherapy intervention, may be tested in other rural areas.