The emergence of the microvariant genotype of Ostreid herpesvirus 1 (OsHV-1 μVar) has caused mass mortalities of Pacific oysters Crassostrea gigas, resulting in significant economic losses in Europe, New Zealand and Australia. There is variability in the occurrence and severity of disease caused by OsHV-1, with the disease incompletely described by the known complex interactions between host, environment and pathogen. There is a need to evaluate the role of anthropogenic factors on this disease expression due to the number of interactions between humans and oysters. A controlled in vivo laboratory infection model was used to assess changes to the susceptibility of 6 mo old Pacific oysters to OsHV-1 challenge after pre-exposure to combinations of stressors. Pre-exposure of oysters to a concentration of the pesticide imidacloprid consistent with the higher range of environmental contamination in some estuaries had no impact on their survival or OsHV-1 viral load. Oysters pre-exposed to air for 24 h prior to OsHV-1 challenge by cohabitation were more resilient to infection. Moderate physical handling that simulated onfarm handling did not affect survival. This indicates that farm management practices implemented prior to OsHV-1 exposure might not specifically predispose oysters to more severe disease, and more complex confounding factors need to be considered. It is likely that changes in host physiology during emersion provide the host with increased resilience to disease caused by OsHV-1. Continued investigation of the effect of air exposure in the field will aid in validating the results from this laboratory experiment.

中文翻译：

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空气暴露、处理压力和吡虫啉对巨牡蛎对 ostreid 疱疹病毒 1 (OsHV-1) 易感性的影响

Ostreid herpesvirus 1 (OsHV-1 μVar) 微变异基因型的出现导致太平洋牡蛎 Crassostrea gigas 大量死亡，在欧洲、新西兰和澳大利亚造成重大经济损失。由 OsHV-1 引起的疾病的发生率和严重程度各不相同，宿主、环境和病原体之间已知的复杂相互作用不能完全描述该疾病。由于人类和牡蛎之间相互作用的数量，需要评估人为因素对这种疾病表达的作用。使用受控的体内实验室感染模型来评估 6 个月龄的太平洋牡蛎在预暴露于压力源组合后对 OsHV-1 攻击的易感性的变化。将牡蛎预先暴露于一定浓度的杀虫剂吡虫啉与某些河口环境污染范围较高的情况一致，对其存活率或 OsHV-1 病毒载量没有影响。在 OsHV-1 攻击前通过同居预暴露于空气 24 小时的牡蛎对感染更具抵抗力。模拟农场处理的适度物理处理不会影响生存。这表明在 OsHV-1 暴露之前实施的农场管理实践可能不会特别使牡蛎易患更严重的疾病，需要考虑更复杂的混杂因素。出现期间宿主生理学的变化很可能使宿主对 OsHV-1 引起的疾病具有更强的抵抗力。