RAPID: Evaluating the potential for SARS-CoV-2 spillback infections of native North American wildlife

SARS-CoV-2起源于蝙蝠，可能在感染人类之前通过另一种动物传播。其目的是确定两种北美本土野生动物物种是否可以感染SARS-CoV-2，这是COVID-19的病原体，迄今为止尚未进行评估。臭鼬和浣熊与其他已知易感染这种病毒的物种密切相关，并且在人类环境中非常丰富，经常食用人类垃圾。这两个物种也经常在野生动物研究和康复环境中处理，从而造成病毒可能从人身上回流到它们身上的情况。此外，这项研究将调查臭鼬与臭鼬和浣熊与浣熊之间的传播是否可能，需要预测如果这种病毒蔓延到我们的本土野生动物中会发生什么;最坏的情况是这些物种成为人类病毒的宿主。臭鼬和浣熊将接种两剂SARS-CoV-2，代表它们可能遇到的环境或与人密切接触时的剂量。接种后将采集鼻和粪便样本，并使用两种检测方法进行检测。还将定期收集血液，以确定这些物种是否产生抗病毒抗体。除了迅速向野生动物管理机构传播这一信息，介绍和出版结果外，这项工作还将培训三名研究生和两名本科生，内容涉及畜牧业、实验感染、以及各种实验室分析。本研究的目的是确定两种代表易感性和生态机会的可能性很高的北美本土野生动物物种-臭鼬和浣熊-容易感染SARS-Cov-2。目前的系统发育证据表明，动物宿主的溢出事件引发了COVID-19大流行，因此，了解动物物种的易感性至关重要。研究人员将评估临床结果、病毒脱落的持续时间和途径以及血清转化和病理学，以了解：1）这些常见和丰富的、生活区周围的哺乳动物野生动物物种的潜在储存状态，2）病毒从人类传播到这些物种的可能性。研究结果将指导积极主动的行动，以管理人类、家畜和野生动物之间的接触，这对抗击持续的COVID-19大流行至关重要。动物将从圈养饲养员处获得，并圈养在BSL 3机构中。每种物种的三对鼻内接种两种剂量的SARS-CoV-2（103和105空斑形成单位）之一。为了确定直接接触传播，在接种后第1天，我们将向每对接种动物中添加一只动物。接种后，将采集用于qrtPCR和病毒分离的鼻拭子和直肠拭子以及接种和直接接触动物的血样，直至21天。由兽医每天监测所有动物的临床体征，并人道处死，从而进行完整的尸检。该RAPID奖项由BIO综合有机系统部门的生理和结构系统集群颁发，使用冠状病毒援助，救济和经济安全（CARES）法案的资金。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

SARS-CoV-2 originated from a bat, likely passing through another animal before it infected people. The objective is to determine if two North American native wildlife species can be infected with SARS-CoV-2, the causative agent of COVID-19, which to date has not been evaluated. Skunks and raccoons are closely related to other species that are known to be susceptible with this virus, and are highly abundant in human environments, frequently consuming human refuse. Both species are also handled frequently in wildlife research and rehabilitation settings—creating situations where spillback of the virus from people to them is likely. Further, this study will investigate whether skunk-to-skunk and racoon-to-raccoon transmission is possible, needed to forecast what would happen if this virus spilled into our native wildlife; the worst case scenario is that these species become reservoirs of the virus for people. Skunks and raccoons will be inoculated with two doses of SARS-CoV-2 that represent doses they might encounter the environment, or when in close contact with people. Nasal and fecal samples will be collected after inoculation and tested using two detection methods. Blood will also be collected at intervals to determine if these species create antibodies against the virus. In addition to rapidly disseminating this information to wildlife management agencies, presenting and publishing the results, this work will train three graduate and two undergraduate students on animal husbandry, experimental infections, and various laboratory analyses.The objective of this study is to identify if two North American native wildlife species that represent a high likelihood of susceptibility and ecological opportunity—skunks and raccoons—are susceptible to infection with SARS-Cov-2. Current phylogenetic evidence indicates a spillover event from an animal host prompted the COVID-19 pandemic, thus, understanding susceptibility of animal species is paramount. Researchers will assess clinical outcome, duration and route of virus shedding, and seroconversion and pathology to understand the: 1) potential reservoir status of these common and abundant, peridomestic, mammalian wildlife species and, 2) likelihood of virus spillover from humans to these species. Results will guide proactive actions to manage contact between humans, domestic animals and wildlife—crucial to combat the ongoing COVID-19 pandemic. Animals will be acquired from a captive breeder and housed in BSL3 facility. Three pairs of each species will be intranasally inoculated with one of two doses of SARS-CoV-2 (103 and 105 plaque forming units). To determine direct contact transmission, at Day 1 post-inoculation, we will add one animal to each pair of inoculated animals. Post-inoculation, nasal and rectal swabs for qrtPCR and virus isolation and blood samples from both inoculated and direct contact animals will be collected up to 21 days. All animals will be monitored for clinical signs daily by a veterinarian and humanely euthanized, whereby a complete post-mortem examination will be conducted. This RAPID award is made by the Physiological and Structural Systems Cluster in the BIO Division of Integrative Organismal Systems, using funds from the Coronavirus Aid, Relief, and Economic Security (CARES) Act.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.