Peak shift and epidemiology in a seasonal host-nematode system
Peak shift and epidemiology in a seasonal host-nematode system
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DOI：
10.1098/rspb.2004.3050
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发表时间：
2005-06-07
影响因子：
4.7
通讯作者：
Hudson, PJ
中科院分区：
文献类型：
--
作者：
Cattadori, IM;Boag, B;Hudson, PJ
深入了解高等脊椎动物寄生虫-宿主关系的动态，需要了解两个重要特征：传播的性质和宿主获得性免疫的发展。一种占主导地位的假说认为，获得性免疫随着感染的累积暴露而发展，因此预测感染高峰强度与宿主年龄之间存在负相关关系。尽管之前的研究通过种群间的比较发现了支持这一假说的证据，但这些结果受到空间效应的干扰。在这项研究中，我们研究了26年来每月采集的兔子自然种群中反形毛圆线虫的感染动态。用体重作为年龄的替代指标，重建了兔的年龄结构，并对2-8月出生的每一只兔的寄主年龄-寄生虫强度关系进行了检验。年龄-强度曲线呈典型的凹形，峰值感染强度与寄主年龄呈显著负相关。雌性成虫在围产期的感染率明显升高，有繁殖能力的成年雌性比成年雄性和未繁殖雌性的感染强度更高。这些发现与宿主对寄生虫感染的获得性免疫反应的假设是一致的，支持了获得性免疫可以用累积接触感染来建模的原理。这些发现还表明，季节性可能是宿主-寄生虫相互作用的重要驱动因素。
Insight into the dynamics of parasite-host relationships of higher vertebrates requires an understanding of two important features: the nature of transmission and the development of acquired immunity in the host. A dominant hypothesis proposes that acquired immunity develops with the cumulative exposure to infection, and consequently predicts a negative relationship between peak intensity of infection and host age at this peak. Although previous studies have found evidence to support this hypothesis through between-population comparisons, these results are confounded by spatial effects. In this study, we examined the dynamics of infection of the nematode Trichostrongylus retortaeformis within a natural population of rabbits sampled monthly for 26 years. The rabbit age structure was reconstructed using body mass as a proxy for age, and the host age-parasite intensity relationship was examined for each rabbit cohort born from February to August. The age-intensity curves exhibited a typical concave shape, and a significant negative relationship was found between peak intensity of infection and host age at this peak. Adult females showed a distinct periparturient rise in T retortaeformis infection, with higher intensities in breeding adult females than adult males and non-breeding females. These findings are consistent with the hypothesis of an acquired immune response of the host to a parasite infection, supporting the principle that acquired immunity can be modelled using the cumulative exposure to infection. These findings also show that seasonality can be an important driver of host-parasite interactions.