The ecology of infectious disease: Effects of host diversity and community composition on Lyme disease risk
The ecology of infectious disease: Effects of host diversity and community composition on Lyme disease risk
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DOI：
10.1073/pnas.0233733100
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发表时间：
2003-01-21
影响因子：
11.1
通讯作者：
Keesing, F
中科院分区：
文献类型：
--
作者：
LoGiudice, K;Ostfeld, RS;Keesing, F
随着人类对生态系统影响的增加，生态系统的生物多样性和群落组成对其功能产生影响的程度是一个日益紧迫的问题。我们提出的证据支持脊椎动物生物多样性的一种新功能，即缓冲人类接触莱姆病蜱的风险。我们测试了稀释效应模型，该模型预测蜱宿主群落中的高物种多样性通过稀释最有能力的疾病储存库（无处不在的白足鼠（白足鼠））的影响来降低媒介感染率。随着生境因破碎化或其他人为力量而退化，东道社区的一些成员消失了。因此，物种贫乏的社区往往有老鼠，但很少有其他宿主，而物种丰富的社区有老鼠，加上许多其他潜在的宿主。我们证明，最常见的非小鼠宿主是莱姆病螺旋体的相对较差的水库，并应通过喂养，但很少感染，蜱减少疾病的流行。通过考虑几乎每一种宿主物种对幼虫蜱虫喂养和感染数量的贡献，我们表明，随着新的宿主物种被添加到一个departamate社区，若虫感染率，一个关键的风险因素，下降。我们识别重要的“稀释宿主”（例如，松鼠），其特征在于高蜱虫负荷、低储集能力和高种群密度，以及“救援宿主”（例如，当鼠密度低时，它们能够保持高疾病风险。我们的研究表明，保护脊椎动物的生物多样性和群落组成可以降低莱姆病的发病率。
The extent to which the biodiversity and community composition of ecosystems affect their functions is an issue that grows ever more compelling as human impacts on ecosystems increase. We present evidence that supports a novel function of vertebrate biodiversity, the buffering of human risk of exposure to Lyme-disease-bearing ticks. We tested the Dilution Effect model, which predicts that high species diversity in the community of tick hosts reduces vector infection prevalence by diluting the effects of the most competent disease reservoir, the ubiquitous white-footed mouse (Peromyscus leucopus). As habitats are degraded by fragmentation or other anthropogenic forces, some members of the host community disappear. Thus, species-poor communities tend to have mice, but few other hosts, whereas species-rich communities have mice, plus many other potential hosts. We demonstrate that the most common nonmouse hosts are relatively poor reservoirs for the Lyme spirochete and should reduce the prevalence of the disease by feeding, but rarely infecting, ticks. By accounting for nearly every host species' contribution to the number of larval ticks fed and infected, we show that as new host species are added to a depauperate community, the nymphal infection prevalence, a key risk factor, declines. We identify important "dilution hosts" (e.g., squirrels), characterized by high tick burdens, low reservoir competence, and high population density, as well as "rescue hosts" (e.g., shrews), which are capable of maintaining high disease risk when mouse density is low. Our study suggests that the preservation of vertebrate biodiversity and community composition can reduce the incidence of Lyme disease.