Biodiversity is commonly believed to reduce risk of vector-borne zoonoses. However, researchers already showed that the effect of biodiversity on disease transmission is not that straightforward. This study focuses on the effect of biodiversity, specifically on the effect of the decoy process (additional hosts distracting vectors from their focal host), on reducing infections of vector-borne diseases in humans. Here, we consider the specific case of Chagas disease and use mathematical population models to observe the impact on human infection of the proximity of chickens, which are incompetent hosts for the parasite but serve as a preferred food source for vectors. We consider three cases as the distance between the two host populations varies: short (when farmers bring chickens inside the home to protect them from predators), intermediate (close enough for vectors with one host to detect the presence of the other host type), and far (separate enclosed buildings such as a home and hen-house). Our analysis shows that the presence of chickens reduces parasite prevalence in humans only at an intermediate distance under the condition that the vector birth rate from feeding on chickens is sufficiently low.

中文翻译：

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诱饵和稀释：无能宿主对南美锥虫病流行的影响

人们普遍认为生物多样性可以降低媒介传播的人畜共患病风险。然而，研究人员已经表明，生物多样性对疾病传播的影响并不是那么简单。本研究侧重于生物多样性的影响，特别是诱饵过程（额外宿主将媒介从其焦点宿主中转移）对减少人类媒介传播疾病感染的影响。在这里，我们考虑了恰加斯病的具体案例，并使用数学种群模型来观察鸡附近对人类感染的影响，鸡是寄生虫的无能宿主，但却是载体的首选食物来源。我们考虑三种情况，因为两个宿主种群之间的距离不同：短（当农民将鸡带入家中以保护它们免受捕食者的侵害时），中间（足够接近一个宿主的载体以检测另一种宿主类型的存在）和远（独立的封闭建筑物，如家和鸡舍）。我们的分析表明，在以鸡为食的媒介出生率足够低的情况下，鸡的存在仅在中等距离内降低了人类寄生虫的流行率。