McMichael Lee, Edson Daniel, Smith Craig, Mayer David, Smith Ina, Kopp Steven, Meers Joanne, Field Hume
University of Queensland, School of Veterinary Science, Gatton, Queensland, Australia.
Biosecurity Queensland, Department of Agriculture and Fisheries, Brisbane, Queensland, Australia.
PLoS One. 2017 Aug 2;12(8):e0182171. doi: 10.1371/journal.pone.0182171. eCollection 2017.
Pteropid bats (flying-foxes) are the natural reservoir of Hendra virus, an emergent paramyxovirus responsible for fatal infection in horses and humans in Australia. Pteropus alecto (the Black flying-fox) and the paraphyletic P. conspicillatus (the Spectacled flying-fox) appear to be the primary reservoir hosts. Previous studies have suggested that physiological and ecological factors may underpin infection dynamics in flying-foxes, and subsequent spillover to horses and in turn humans. We sought to examine temporal trends in urinary cortisol concentration in wild Australian flying-fox populations, to elucidate the putative relationship between Hendra virus infection and physiological stress. Pooled and individual urine samples were non-invasively collected from under roosting flying-foxes at two latitudinally disparate regions in the eastern Australian state of Queensland. Hendra virus detection, and (in individual urine samples) sex and species determination were PCR-based. Urinary cortisol measurement used a validated enzyme immunoassay. We found no direct correlation between increased urinary cortisol and Hendra virus excretion, but our findings do suggest a biologically plausible association between low winter temperatures and elevated cortisol levels in P. alecto in the lower latitude Southeast Queensland roosts. We hypothesize an indirect association between low winter temperatures and increased Hendra virus infection and excretion, mediated by the physiological cost of thermoregulation. Our findings and our approach are directly relevant to elaboration of the disease ecology of Nipah virus and other emerging henipaviruses in bats. More broadly, they inform investigation of emerging disease infection dynamics across the wildlife/livestock/human interface.
狐蝠是亨德拉病毒的天然宿主，亨德拉病毒是一种新出现的副粘病毒，可在澳大利亚导致马和人类致命感染。黑狐蝠（Pteropus alecto）和并系物种眼镜狐蝠（P. conspicillatus）似乎是主要的宿主。先前的研究表明，生理和生态因素可能是狐蝠感染动态的基础，并随后传播给马，进而传播给人类。我们试图研究澳大利亚野生狐蝠种群尿液皮质醇浓度的时间趋势，以阐明亨德拉病毒感染与生理应激之间的假定关系。从澳大利亚昆士兰州东部两个纬度不同地区的栖息狐蝠下方非侵入性地收集混合尿液样本和个体尿液样本。基于聚合酶链反应（PCR）进行亨德拉病毒检测，以及（在个体尿液样本中）性别和物种鉴定。尿液皮质醇测量采用经过验证的酶免疫测定法。我们发现尿液皮质醇增加与亨德拉病毒排泄之间没有直接相关性，但我们的研究结果确实表明，在昆士兰州东南部较低纬度栖息地的黑狐蝠中，冬季低温与皮质醇水平升高之间存在生物学上合理的关联。我们假设冬季低温与亨德拉病毒感染和排泄增加之间存在间接关联，这是由体温调节的生理成本介导的。我们的研究结果和方法与阐明蝙蝠中尼帕病毒和其他新兴亨尼帕病毒的疾病生态学直接相关。更广泛地说，它们为跨野生动物/家畜/人类界面的新发疾病感染动态研究提供了信息。
