Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
Khao Kheow Open Zoo, Bangpra, Sriracha, Chonburi 20110, Thailand.
J Vet Med Sci. 2020 Dec 26;82(12):1808-1815. doi: 10.1292/jvms.20-0309. Epub 2020 Oct 19.
Elephant endotheliotropic herpesvirus (EEHV) infection is one of the most common diseases in young elephants, causing severe fatal hemorrhagic disease. Subclinical infection was previously described; however, information about the factors associated with virus shedding and reactivation were scarce. To identify the biological and environmental factors related with EEHV detection, blood and oral swab samples were collected from nine captive Asian elephants in Thailand for one year and tested for EEHV presence using real-time PCR. Data including hematological values, management, environmental temperature, and serum cortisol levels were also recorded and analyzed. Results showed that the viral detection frequency ranged from 0-25%. The highest detection frequency was found in the two youngest elephants, aged less than 15 years. Three types of viruses, EEHV1, EEHV4, and EEHV5, were found in this study, which also detected mixed infection in five elephants. Additionally, the study found that sample type, changes in hematological values, management and health issues, and serum cortisol levels were not associated with herpesvirus detection in the elephants. However, EEHV detection percentage was significantly increased in the summer (mid-Feb to mid-May), possibly due to body fitness reduction from food source limitation and low nutrient content. To obtain a broad aspect of EEHV management, long-term EEHV monitoring is highly recommended in every captive elephant herd.
大象内皮细胞疱疹病毒（EEHV）感染是幼象最常见的疾病之一，可导致严重的致命性出血性疾病。此前曾描述过亚临床感染；然而，与病毒脱落和重新激活相关的因素信息仍然很少。为了确定与 EEHV 检测相关的生物学和环境因素，从泰国的 9 头圈养亚洲象采集了血液和口腔拭子样本，并用实时 PCR 检测 EEHV 的存在。还记录和分析了包括血液学值、管理、环境温度和血清皮质醇水平在内的数据。结果表明，病毒检测频率在 0-25%之间。在年龄小于 15 岁的两只最小的大象中发现了最高的检测频率。在本研究中发现了三种病毒，即 EEHV1、EEHV4 和 EEHV5，还在五头大象中检测到了混合感染。此外，研究发现，样本类型、血液学值的变化、管理和健康问题以及血清皮质醇水平与大象中疱疹病毒的检测无关。然而，EEHV 的检测百分比在夏季（2 月中旬至 5 月中旬）显著增加，可能是由于食物来源有限和营养含量低导致的身体适应能力下降。为了全面了解 EEHV 的管理，强烈建议在每个圈养大象群体中进行长期的 EEHV 监测。
