Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH) , Hamilton, MT , USA.
Front Bioeng Biotechnol. 2016 May 11;4:40. doi: 10.3389/fbioe.2016.00040. eCollection 2016.
The tick-borne flaviviruses (TBFV) occur worldwide and the tick-borne encephalitis virus (TBEV) members of the group often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that the virus can be excreted in the milk of infected animals. Additionally, the virus remains infectious after exposure to low pH levels, similar to those found in the stomach. To evaluate the survival of virus in milk, we studied the stability of the BSL-2 TBFV, Langat virus, in unpasteurized goat milk over time and after different thermal treatments. Virus was stable in milk maintained under refrigeration conditions; however, there was a marked reduction in virus titer after incubation at room temperature. High temperature, short time pasteurization protocols completely inactivated the virus. Interestingly, simulation of a typical thermal regime utilized for cheese did not completely inactivate the virus in milk. These findings stress the importance of proper milk handling and pasteurization processes in areas endemic for TBEV.
蜱传黄病毒（TBFV）在全球范围内存在，该病毒群中的蜱传脑炎病毒（TBEV）通常会导致人类严重的、使人虚弱的神经系统疾病。尽管感染的主要途径是被感染的蜱叮咬，但通过食用受 TBEV 污染的乳制品进行食源性感染也有充分记录，并导致在流行地区的一些疾病。用 TBEV 对山羊、牛和绵羊进行实验性感染表明，该病毒可以在受感染动物的乳汁中排出。此外，该病毒在暴露于类似于胃中发现的低 pH 值时仍保持感染性。为了评估病毒在牛奶中的存活情况，我们研究了时间和不同热处理后，BSL-2 TBFV、Langat 病毒在未经巴氏消毒的山羊奶中的稳定性。病毒在冷藏条件下保持稳定；然而，在室温下孵育后，病毒滴度明显降低。高温短时间巴氏消毒方案可完全灭活病毒。有趣的是，用于奶酪的典型热处理模拟并未使牛奶中的病毒完全失活。这些发现强调了在 TBEV 流行地区正确处理和巴氏消毒牛奶的重要性。
