Plowright Raina K, Peel Alison J, Streicker Daniel G, Gilbert Amy T, McCallum Hamish, Wood James, Baker Michelle L, Restif Olivier
Montana State University, Department of Microbiology and Immunology, Bozeman, Montana, United States of America.
Center for Infectious Disease Dynamics, Pennsylvania State University, State College, Pennsylvania, United States of America.
PLoS Negl Trop Dis. 2016 Aug 4;10(8):e0004796. doi: 10.1371/journal.pntd.0004796. eCollection 2016 Aug.
Progress in combatting zoonoses that emerge from wildlife is often constrained by limited knowledge of the biology of pathogens within reservoir hosts. We focus on the host-pathogen dynamics of four emerging viruses associated with bats: Hendra, Nipah, Ebola, and Marburg viruses. Spillover of bat infections to humans and domestic animals often coincides with pulses of viral excretion within bat populations, but the mechanisms driving such pulses are unclear. Three hypotheses dominate current research on these emerging bat infections. First, pulses of viral excretion could reflect seasonal epidemic cycles driven by natural variations in population densities and contact rates among hosts. If lifelong immunity follows recovery, viruses may disappear locally but persist globally through migration; in either case, new outbreaks occur once births replenish the susceptible pool. Second, epidemic cycles could be the result of waning immunity within bats, allowing local circulation of viruses through oscillating herd immunity. Third, pulses could be generated by episodic shedding from persistently infected bats through a combination of physiological and ecological factors. The three scenarios can yield similar patterns in epidemiological surveys, but strategies to predict or manage spillover risk resulting from each scenario will be different. We outline an agenda for research on viruses emerging from bats that would allow for differentiation among the scenarios and inform development of evidence-based interventions to limit threats to human and animal health. These concepts and methods are applicable to a wide range of pathogens that affect humans, domestic animals, and wildlife.
对抗源自野生动物的人畜共患病方面的进展，常常受到对储存宿主内病原体生物学了解有限的制约。我们聚焦于与蝙蝠相关的四种新兴病毒的宿主 - 病原体动态：亨德拉病毒、尼帕病毒、埃博拉病毒和马尔堡病毒。蝙蝠感染向人类和家畜的溢出，通常与蝙蝠种群内病毒排泄高峰同时发生，但驱动此类高峰的机制尚不清楚。当前关于这些新兴蝙蝠感染的研究主要有三种假说。其一，病毒排泄高峰可能反映由宿主种群密度和接触率的自然变化驱动的季节性流行周期。如果康复后产生终身免疫，病毒可能在局部消失，但通过迁移在全球持续存在；无论哪种情况，一旦出生补充了易感群体，就会发生新的疫情爆发。其二，流行周期可能是蝙蝠体内免疫力下降的结果，通过波动的群体免疫使病毒在局部传播。其三，高峰可能由持续感染的蝙蝠通过生理和生态因素的组合间歇性排毒产生。这三种情况在流行病学调查中可能产生相似的模式，但预测或管理每种情况导致的溢出风险的策略将有所不同。我们概述了一项针对源自蝙蝠的病毒的研究议程，该议程将有助于区分这些情况，并为制定基于证据的干预措施提供信息，以限制对人类和动物健康的威胁。这些概念和方法适用于广泛影响人类、家畜和野生动物的病原体。
