UMMISCO, IRD / Sorbonne Université, Bondy, France.
MIVEGEC, IRD, CNRS, Université Montpellier, Montpellier, France.
PLoS Negl Trop Dis. 2018 May 10;12(5):e0006483. doi: 10.1371/journal.pntd.0006483. eCollection 2018 May.
Multi-species interactions can often have non-intuitive consequences. However, the study of parasite interactions has rarely gone beyond the effects of pairwise combinations of species, and the outcomes of multi-parasite interactions are poorly understood. We investigated the effects of co-infection by four gastrointestinal helminth species on the development of cerebral malaria among Plasmodium falciparum-infected patients. We characterized associations among the helminth parasite infra-community, and then tested for independent (direct) and co-infection dependent (indirect) effects of helminths on cerebral malaria risk. We found that infection by Ascaris lumbricoides and Trichuris trichiura were both associated with direct reductions in cerebral malaria risk. However, the benefit of T. trichiura infection was halved in the presence of hookworm, revealing a strong indirect effect. Our study suggests that the outcome of interactions between two parasite species can be significantly modified by a third, emphasizing the critical role that parasite community interactions play in shaping infection outcomes.
多物种相互作用通常会产生非直观的后果。然而，寄生虫相互作用的研究很少超出物种两两组合的影响，多寄生虫相互作用的结果也知之甚少。我们研究了四种胃肠道寄生虫感染对疟原虫感染患者脑疟发展的影响。我们描述了寄生虫群落内的关联，然后测试了寄生虫对脑疟风险的独立（直接）和共感染依赖（间接）影响。我们发现，感染蛔虫和鞭虫都与直接降低脑疟风险有关。然而，在存在钩虫的情况下，感染鞭虫的益处减半，这表明存在强烈的间接影响。我们的研究表明，两种寄生虫之间相互作用的结果可以被第三种寄生虫显著改变，这强调了寄生虫群落相互作用在塑造感染结果方面的关键作用。
