The impact and social ecology of bacterial zoonoses in northern Tanzania

众所周知，人畜共患病病原体--可导致疾病从动物传染给人类的病原体--是人类新出现疾病的主要原因，但在甲型流感H5N1和SARS冠状病毒等备受瞩目的新出现人畜共患病的阴影下，在局部地区流行的人畜共患病往往被忽视。然而，人们越来越认识到，许多这些地方性人畜共患病在公共卫生和牲畜健康方面造成了巨大的疾病负担，这些双重影响导致受影响最严重的边缘化社区的贫困循环永久化。在这项研究的所在地坦桑尼亚北部，由三种人畜共患病(钩端螺旋体病、Q热和布鲁氏菌病)引起的人类疾病导致的住院人数是疟疾的11倍。然而，对于动物宿主之间的传播模式、哪些宿主物种对人类疾病负有责任，或者在不同环境中人类疾病风险的关键行为决定因素，人们几乎一无所知。这项研究的目的是量化这三种人畜共患病在不同社区(位于城镇边缘、农业景观和牧区)的影响，并对环境和社会关系对疾病风险的影响产生预测性的了解。具体地说，它们涉及动物之间以及动物与人类之间的感染和传播模式，传播的生态和社会决定因素，以及疾病传播的文化、社会、行为、经济和环境层面。这项工作的结果直接适用于与畜牧业生产相关的公共卫生和经济发展的政策和实践。

It is well recognized that zoonotic pathogens - agents which can lead to diseases that are transmitted from animal to human populations - predominate as the cause of emerging human diseases, but in the shadow of the high-profile emerging zoonoses, such as Influenza A H5N1 and SARS corona virus, zoonoses that are prevalent in localised areas have often been overlooked. However, awareness is growing that many of these localised zoonoses are responsible for a substantial burden of disease both in terms of public health and livestock health, and that these dual impacts contribute to perpetuating cycles of poverty in the marginalized communities that are most affected. In northern Tanzania, the location of this research, human diseases caused by three zoonotic diseases (leptospirosis, Q-fever and brucellosis) result in 11 times as many hospital admissions as malaria. However, almost nothing is known about transmission patterns among animal hosts, which host species are responsible for human disease, or the key behavioural determinants of human disease risk in different settings. The aim of this research is to quantify the impacts of these three zoonoses in different communities (located at the edge of town, in agricultural landscapes and in pastoral areas) and to develop a predictive understanding of the impact of environmental and social relationships on disease risk. Specifically, they address infection and transmission patterns between animals and from animals to humans, ecological and social determinants of transmission, and the cultural, social, behavioural and economic and environmental dimensions of disease communication. The results of this work are directly applicable to policy and practice that is relevant to both public health and economic development related to livestock production.