Department of Forestry and Environmental Resources, North Carolina State University, , Raleigh, NC 27607, USA, Department of Biological Sciences and Keck Behavioral Biology Group, North Carolina State University, , Raleigh, NC 27607, USA.
Proc Biol Sci. 2013 Sep 25;280(1771):20131847. doi: 10.1098/rspb.2013.1847. Print 2013 Nov 22.
Species loss can result in the subsequent loss of affiliate species. Though largely ignored to date, these coextinctions can pose threats to human health by altering the composition, quantity and distribution of zoonotic parasites. We simulated host extinctions from more than 1300 host-parasite associations for 29 North American carnivores to investigate changes in parasite composition and species richness. We also explored the geography of zoonotic parasite richness under three carnivore composition scenarios and examined corresponding levels of human exposure. We found that changes in parasite assemblages differed among parasite groups. Because viruses tend to be generalists, the proportion of parasites that are viruses increased as more carnivores went extinct. Coextinction of carnivore parasites is unlikely to be common, given that few specialist parasites exploit hosts of conservation concern. However, local extirpations of widespread carnivore hosts can reduce overall zoonotic richness and shift distributions of parasite-rich areas. How biodiversity influences disease risks remains the subject of debate. Our results make clear that hosts vary in their contribution to human health risks. As a consequence, so too does the loss (or gain) of particular hosts. Anticipating changes in host composition in future environments may help inform parasite conservation and disease mitigation efforts.
物种的消失可能导致相关物种的随后消失。尽管这些共灭绝在很大程度上被忽视了，但它们通过改变人畜共患寄生虫的组成、数量和分布，可能对人类健康构成威胁。我们模拟了来自 1300 多个宿主-寄生虫关联的超过 29 种北美的食肉动物的宿主灭绝，以研究寄生虫组成和物种丰富度的变化。我们还探讨了在三种食肉动物组成情景下的人畜共患病寄生虫丰富度的地理分布，并检查了相应的人类暴露水平。我们发现，寄生虫组合的变化在不同的寄生虫群体之间存在差异。由于病毒往往是多面手，随着更多的食肉动物灭绝，寄生虫中病毒的比例增加。考虑到很少有专门的寄生虫利用受保护的宿主，食肉动物寄生虫的共灭绝不太可能很常见。然而，广泛的食肉动物宿主的局部灭绝可能会降低整体人畜共患病的丰富度，并改变寄生虫丰富地区的分布。生物多样性如何影响疾病风险仍然是一个争论的话题。我们的结果清楚地表明，宿主在对人类健康风险的贡献方面存在差异。因此，特定宿主的损失（或获得）也是如此。预测未来环境中宿主组成的变化可能有助于告知寄生虫保护和疾病缓解工作。
