Implications of Heterogeneous Biting Exposure and Animal Hosts on Trypanosomiasis brucei gambiense Transmission and Control.
Implications of Heterogeneous Biting Exposure and Animal Hosts on Trypanosomiasis brucei gambiense Transmission and Control.
复制标题
异质叮咬暴露和动物宿主对布氏冈比亚锥虫病传播和控制的影响。
DOI：
10.1371/journal.pcbi.1004514
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发表时间：
2015-10
影响因子：
4.3
通讯作者：
Chitnis N
中科院分区：
文献类型：
--
作者：
Stone CM;Chitnis N
冈比亚型昏睡病是一种被忽视的热带疾病，被认为是人类传染病。然而，这种寄生虫在人群中以相当罕见的水平持续存在，因此已经假定存在动物宿主。澄清动物宿主宿主对通过干预中断昏睡病传播的可行性的影响是一个紧迫的问题。我们开发了一个数学模型，允许人类接触采采蝇的异质性，动物种群的传播感染的能力不同，以调查两种已建立的技术的有效性，筛查和治疗高危人群，和病媒控制。重要的是，在这两种假设下，在高传播地区支持采用人体筛查和病媒控制的综合办法。然而，加强病媒控制更有可能消除传播，而加强人体筛查则缩短了消除时间。非人类动物宿主在HAT传播中发挥了重要作用，但作用不同，这取决于它们是否作为宿主。如果它们不是水库，敏感性分析表明，它们的吸引力可能会成为采采蝇叮咬的水槽。这些结果强调了了解昏睡病的生态和环境背景在优化综合干预措施中的重要性，特别是在中等和低传播强度环境中。昏睡病是一种主要袭击撒哈拉以南非洲贫困人口的疾病，已作为一个公共卫生问题被定为消除的目标。尽管经过数十年的控制行动，这种疾病仍然是个谜，并且能够在低患病率的人群中持续存在。这里研究两种机制，可以让持久性在这样的水平。人类对采采蝇的异质暴露被模拟为人类通勤到高媒介容量区域的子集。此外，非人类动物也可作为储库种属。我们开发，参数化，并调查了昏睡病传播的模型，以深入了解这些假设对消除使用筛选和治疗的人类和病媒控制的前景的影响。补充使用病媒控制增加了消除的可能性，并缩短了达到消除的持续时间。当动物确实有助于传播时，或者当人类对筛查行动的覆盖率和遵守率较低时，例如由于无法接触到最有接触风险的人类，这一点更加明显。这些结果可以为公共卫生官员提供关于何时考虑用额外措施补充人类治疗的见解，从而改善消除这种疾病的前景。
The gambiense form of sleeping sickness is a neglected tropical disease, which is presumed to be anthroponotic. However, the parasite persists in human populations at levels of considerable rarity and as such the existence of animal reservoirs has been posited. Clarifying the impact of animal host reservoirs on the feasibility of interrupting sleeping sickness transmission through interventions is a matter of urgency. We developed a mathematical model allowing for heterogeneous exposure of humans to tsetse, with animal populations that differed in their ability to transmit infections, to investigate the effectiveness of two established techniques, screening and treatment of at-risk populations, and vector control. Importantly, under both assumptions, an integrated approach of human screening and vector control was supported in high transmission areas. However, increasing the intensity of vector control was more likely to eliminate transmission, while increasing the intensity of human screening reduced the time to elimination. Non-human animal hosts played important, but different roles in HAT transmission, depending on whether or not they contributed as reservoirs. If they did not serve as reservoirs, sensitivity analyses suggested their attractiveness may instead function as a sink for tsetse bites. These outcomes highlight the importance of understanding the ecological and environmental context of sleeping sickness in optimizing integrated interventions, particularly for moderate and low transmission intensity settings. Sleeping sickness, a disease that strikes predominantly poor populations in sub-Saharan Africa, has been targeted for elimination as a public health problem. Despite decades of control operations the disease remains enigmatic and is capable of persisting in populations at low levels of prevalence. Two mechanisms are investigated here that could allow persistence at such levels. Heterogeneous exposure of humans to tsetse is modelled as a subset of humans commuting to areas of high vectorial capacity. Additionally, non-human animals may act as reservoir species. We developed, parameterized, and investigated a model of sleeping sickness transmission to gain insight into the impact of these assumptions on the prospects of elimination using screening and treatment of humans and vector control. Supplemental use of vector control increased the probability of elimination and decreased the duration until elimination was achieved. This was more pronounced when animals did contribute to transmission, or when coverage and compliance of humans with screening operations was lower, for instance due to an inability to reach the humans at greatest risk of exposure. These results can provide insights to public health officials as to when to consider supplementing human treatment with additional measures, and thereby improve the prospects of elimination of this disease.