Heterospecific competitors and seasonality can affect host physiology and behavior: key factors in disease transmission
Heterospecific competitors and seasonality can affect host physiology and behavior: key factors in disease transmission
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DOI：
10.1002/ecs2.3494
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发表时间：
2021-06-01
期刊：
影响因子：
2.7
通讯作者：
Luis, Angela D.
中科院分区：
文献类型：
--
作者：
Eleftheriou, Andreas;Kuenzi, Amy J.;Luis, Angela D.
生态和环境因素可影响传染病的传播。它们可以通过对宿主易感性和感染暴露的影响来实现这一点，这分别由宿主生理和行为控制。为了更好地为疾病控制提供信息，需要更多关于外在因素如何影响决定传播的生理和行为过程的信息。我们调查了如何异源竞争对手和季节性可能会影响主机的易感性和种内接触率使用直接传播的疾病系统，北美鹿鼠（Peromyscus maniculatus）-辛诺布尔汉坦病毒（SNV）系统。在美国蒙大拿州西部的草原上，鹿鼠与占优势的田鼠（Microtus spp.）和鼩（Sorex spp.）体验季节性的温和气候。较高的SNV传播主要发生在春季/夏季，此时生理和行为的变化可能是有影响力的贡献者。我们假设：（1）田鼠，在较小程度上，鼩，将诱导慢性应激，抑制免疫力，并可能改变鹿鼠的接触率;（2）在春季/夏季，鹿鼠可能会经历慢性应激，抑制免疫力，和更高的接触率，这可能有助于解释报告的季节性在SNV传播。两年多来，我们在蒙大拿州西部的四个网格中捕获了小型哺乳动物。对鹿小鼠的粪便和血液进行采样，并评估疤痕数量、人口统计学和身体状况评分（BCS）。我们用粪便皮质酮代谢物（FCM）、中性粒细胞/淋巴细胞（N/L）比值和BCS评估应激生理学，用白色血细胞（WBC）计数评估免疫力，用瘢痕数量评估接触率。我们发现，鼩密度与应激反应FCM呈负相关，提示慢性应激。此外，尽管存在复杂的相互作用，但鼩 鼱和田鼠的密度与BCS呈负相关，但与疤痕数量存在差异。N/L比值在春季/夏季较高，而WBC计数在夏季较低，分别提示慢性应激和免疫抑制。我们的研究结果表明，（1）异源竞争者可能通过应激生理学和接触率对疾病传播产生不同的影响，（2）慢性应激，免疫抑制和较高的接触率可能有助于解释为什么以前在蒙大拿州的春季/夏季报告了较高的SNV传播。我们的发现可能会扩展到其他直接传播的疾病系统。
Ecological and environmental factors can influence the transmission of infectious diseases. They can accomplish this via effects on host susceptibility and exposure to infection, which are governed by host physiology and behavior, respectively. To better inform disease control, more information is needed about how extrinsic factors affect physiological and behavioral processes that determine transmission. We investigated how heterospecific competitors and seasonality may influence host susceptibility and intraspecific contact rates using a directly transmitted disease system, the North American deer mouse (Peromyscus maniculatus)-Sin Nombre hantavirus (SNV) system. In grasslands of western Montana, USA, deer mice compete with dominant voles (Microtus spp.) and shrews (Sorex spp.) and experience a seasonal temperate climate. Higher SNV transmission occurs primarily during spring/summer, when changes in physiology and behavior may serve as influential contributors. We hypothesized that (1) voles, and to a lesser extent shrews, will induce chronic stress, suppress immunity, and may change contact rates of deer mice; and (2) during spring/summer, deer mice may experience chronic stress, suppressed immunity, and higher contact rates, which may help explain the reported seasonality in SNV transmission. Over two years, we trapped small mammals at four grids in western Montana. Deer mice were sampled for feces and blood and evaluated for scar numbers, demography, and body condition scores (BCSs). We evaluated stress physiology with fecal corticosterone metabolites (FCMs), neutrophil/lymphocyte (N/L) ratios and BCSs, immunity with white blood cell (WBC) counts, and contact rates with scar numbers. We found that shrew density was negatively associated with stress response FCMs, suggestive of chronic stress. Additionally, although complex interactions existed, shrew and vole densities were negatively associated with BCSs, but differentially with scar numbers. N/L ratios were higher in spring/summer, whereas WBC counts were lower in summer, suggestive of chronic stress and suppressed immunity, respectively. Our results suggest that (1) heterospecific competitors may differentially influence disease transmission via stress physiology and contact rates, and that (2) chronic stress, suppressed immunity, and higher contact rates may help explain why higher SNV transmission has been previously reported during spring/summer in Montana. Our findings may extend to other directly transmitted disease systems.