Enteric viruses, such as human norovirus (NoV) and hepatitis A virus (HAV), are the major causes of foodborne illnesses worldwide. These viruses have low infectious dose, and may remain infectious for weeks in the environment and food. Limited information is available regarding viral survival and transmission in low-moisture foods (LMF). LMFs are generally considered as ready-to-eat products, which undergo no or minimal pathogen reduction steps. However, numerous foodborne viral outbreaks associated with LMFs have been reported in recent years. The objective of this study was to examine the survival of foodborne viruses in LMFs during 4-week storage at ambient temperature and to evaluate the efficacy of advanced oxidative process (AOP) treatment in the inactivation of these viruses. For this purpose, select LMFs such as pistachios, chocolate, and cereal were inoculated with HAV and the norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), then viral survival on these food matrices was measured over a four-week incubation at ambient temperature, by both plaque assay and droplet-digital RT-PCR (ddRT-PCR) using the modified ISO-15216 method as well as the magnetic bead assay for viral recovery. We observed an approximately 0.5 log reduction in viral genome copies, and 1 log reduction in viral infectivity for all three tested viruses following storage of select inoculated LMFs for 4 weeks. Therefore, the present study shows that the examined foodborne viruses can persist for a long time in LMFs. Next, we examined the inactivation efficacy of AOP treatment, which combines UV-C, ozone, and hydrogen peroxide vapor, and observed that while approximately 100% (4 log) inactivation can be achieved for FCV, and MNV in chocolate, the inactivation efficiency diminishes to approximately 90% (1 log) in pistachios and 70% (< 1 log) in cereal. AOP treatment could therefore be a good candidate for risk reduction of foodborne viruses from certain LMFs depending on the food matrix and surface of treatment.

肠道病毒，例如人类诺如病毒 (NoV) 和甲型肝炎病毒 (HAV)，是全球食源性疾病的主要原因。这些病毒具有低感染剂量，并且可能在环境和食物中保持感染数周。关于低水分食品 (LMF) 中病毒存活和传播的信息有限。LMF 通常被认为是即食产品，不经过或只经过最少的病原体减少步骤。然而，近年来报告了许多与 LMF 相关的食源性病毒爆发。本研究的目的是检查 LMF 中食源性病毒在环境温度下储存 4 周期间的存活情况，并评估高级氧化过程 (AOP) 处理在灭活这些病毒方面的功效。为此，选择 LMF，例如开心果、巧克力、和谷物接种 HAV 和诺如病毒替代物、鼠诺如病毒 (MNV) 和猫杯状病毒 (FCV)，然后在环境温度下通过噬菌斑测定和液滴数字化检测在 4 周内测量这些食物基质上的病毒存活率RT-PCR (ddRT-PCR) 使用改进的 ISO-15216 方法以及用于病毒恢复的磁珠测定。我们观察到，在选择接种的 LMF 储存 4 周后，所有三种测试病毒的病毒基因组拷贝数减少了约 0.5 个对数级，病毒感染性降低了 1 个对数级。因此，本研究表明，所检测的食源性病毒可以在 LMF 中长期存在。接下来，我们检查了结合 UV-C、臭氧和过氧化氢蒸汽的 AOP 处理的灭活功效，并观察到，虽然巧克力中的 FCV 和 MNV 可以实现大约 100% (4 log) 的灭活，但开心果中的灭活效率降低到大约 90% (1 log)，谷物中的灭活效率降低到 70% (< 1 log)。因此，根据食物基质和处理表面，AOP 处理可能是降低来自某些 LMF 的食源性病毒风险的良好候选者。