Chen Lifan, Tan Zhiying, Kong Ping, Zhou Yanli, Zhou Liang
School of Arts and Sciences Shanghai University of Medicine and Health Sciences Shanghai China.
School of Health Science and Engineering University of Shanghai for Science and Technology Shanghai China.
Ecol Evol. 2024 Mar 1;14(3):e11082. doi: 10.1002/ece3.11082. eCollection 2024 Mar.
A central goal of disease ecology is to identify the factors that drive the spread of infectious diseases. Changes in vector richness can have complex effects on disease risk, but little is known about the role of vector competence in the relationship between vector richness and disease risk. In this study, we firstly investigated the combined effects of vector competence, interspecific competition, and feeding interference on disease risk through a two-vector, one-host SIR-SI model, and obtained threshold conditions for the occurrence of dilution and amplification effects. Secondly, we extended the above model to the case of vectors and assumed that all vectors were homogeneous to obtain analytic expressions for disease risk. It was found that in the two-vector model, disease risk declined more rapidly as interspecific competition of the high-competence vector increased. When vector richness increases, the positive effects of adding a high-competence vector species on disease transmission may outweigh the negative effects of feeding interference due to increased vector richness, making an amplification effect more likely to occur. While the addition of a highly competitive vector species may exacerbate the negative effects of feeding interference, making a dilution effect more likely to occur. In the -vector model, the effect of increased vector richness on disease risk was fully driven by the strength of feeding interference and interspecific competition, and changes in vector competence only quantitatively but not qualitatively altered the vector richness-disease risk relationship. This work clarifies the role of vector competence in the relationship between vector richness and disease risk and provides a new perspective for studying the diversity-disease relationship. It also provides theoretical guidance for vector management and disease prevention strategies.
疾病生态学的一个核心目标是确定推动传染病传播的因素。病媒丰富度的变化可能对疾病风险产生复杂影响，但对于病媒传播能力在病媒丰富度与疾病风险关系中的作用知之甚少。在本研究中，我们首先通过一个双病媒、单宿主的SIR - SI模型，研究了病媒传播能力、种间竞争和取食干扰对疾病风险的综合影响，并获得了稀释和放大效应发生的阈值条件。其次，我们将上述模型扩展到多个病媒的情况，并假设所有病媒都是同质的，以获得疾病风险的解析表达式。研究发现，在双病媒模型中，随着高传播能力病媒种间竞争的增加，疾病风险下降得更快。当病媒丰富度增加时，添加一个高传播能力病媒物种对疾病传播的积极影响可能超过因病媒丰富度增加导致的取食干扰的负面影响，从而更有可能产生放大效应。而添加一个高竞争力病媒物种可能会加剧取食干扰的负面影响，从而更有可能产生稀释效应。在多病媒模型中，病媒丰富度增加对疾病风险的影响完全由取食干扰强度和种间竞争驱动，病媒传播能力的变化仅在数量上而非质量上改变了病媒丰富度与疾病风险的关系。这项工作阐明了病媒传播能力在病媒丰富度与疾病风险关系中的作用，为研究多样性与疾病关系提供了新的视角。它还为病媒管理和疾病预防策略提供了理论指导。
