Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
Equine Vet J. 2021 Mar;53(2):349-355. doi: 10.1111/evj.13313. Epub 2020 Jul 7.
Equid herpesvirus type 1 (EHV-1) is ubiquitous in equine populations causing respiratory disease, and complications including late-term abortion and neurological disease. Eradication of EHV-1 from housing environments that typically contain unsealed wood and porous bedding materials can be challenging. However, consideration should be given to take advantage of the viral envelope's susceptibility to environmental conditions.
To determine environmental persistence of EHV-1 on materials and in environmental conditions commonly found in equine facilities. We hypothesised that environmental conditions and materials would limit environmental persistence of EHV-1 in horse housing environments.
Experimental study.
Standard inoculum of EHV-1 strain OH03 was applied to leather, polyester-cotton fabric, two bedding materials (pinewood shavings and wheat straw) and polystyrene (plastic), and placed under three different environmental conditions (4°C, indoors and outdoors). Virus titration and quantitative PCR (qPCR) were performed at six time points between 0 and 48 hours and the number of plaque-forming units (PFUs) was determined.
Viable EHV-1 was recovered up to 48 hours from all material-environmental condition combinations, with persistence decreasing over time. In general, outdoor environment had the greatest impact, irrespective of material tested, followed by indoor environment and 4°C. On average, wood shavings had the greatest impact on persistence, followed by leather, straw, fabric and polystyrene.
The inoculum used in this study was not in a milieu consistent with nasal secretions. As such, virus particles may have been more sensitive to the materials and/or environmental conditions evaluated.
Environmental factors had variable effects on environmental persistence. Although there were significant reductions in PFUs within the first 3 hours, irrespective of environment-material evaluated, viable virus was still recovered at 48 hours likely representing a transmission risk. Barrier precautions should be used to prevent spread of EHV-1 from unrecognised environmental reservoirs.
马疱疹病毒 1 型（EHV-1）在马群中普遍存在，可引起呼吸道疾病，以及包括晚期流产和神经疾病在内的并发症。根除通常含有未密封木材和多孔寝具材料的住房环境中的 EHV-1 可能具有挑战性。然而，应该考虑利用病毒包膜对环境条件的敏感性。
确定 EHV-1 在马厩环境中常见的材料和环境条件下的环境持久性。我们假设环境条件和材料会限制 EHV-1 在马厩环境中的环境持久性。
实验研究。
将 EHV-1 菌株 OH03 的标准接种物应用于皮革、聚酯棉织物、两种寝具材料（木屑和麦秸）和聚苯乙烯（塑料），并置于三种不同的环境条件（4°C、室内和室外）下。在 0 至 48 小时的六个时间点进行病毒滴定和定量 PCR（qPCR），并确定噬菌斑形成单位（PFU）的数量。
在所有材料-环境条件组合中，均可在 48 小时内回收有活力的 EHV-1，且随着时间的推移，其持久性逐渐降低。一般来说，无论测试的材料如何，室外环境的影响最大，其次是室内环境和 4°C。平均而言，木屑对持久性的影响最大，其次是皮革、稻草、织物和聚苯乙烯。
本研究中使用的接种物与鼻腔分泌物不一致。因此，病毒颗粒可能对评估的材料和/或环境条件更敏感。
环境因素对环境持久性有不同的影响。尽管在最初的 3 小时内，无论评估的环境-材料如何，PFU 都有显著减少，但在 48 小时内仍可回收有活力的病毒，这可能代表着传播风险。应采取隔离预防措施，防止 EHV-1 从未被识别的环境储库传播。
