Sripiboon Supaphen, Jackson Bethany, Ditcham William, Holyoake Carly, Robertson Ian, Thitaram Chatchote, Tankaew Pallop, Letwatcharasarakul Preeda, Warren Kristin
College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, 6150, Western Australia, Australia; Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Murdoch, 6150, Western Australia, Australia.
Infect Genet Evol. 2016 Oct;44:487-494. doi: 10.1016/j.meegid.2016.08.004. Epub 2016 Aug 6.
Elephant Endotheliotropic Herpesvirus (EEHV) is emerging as a new threat for elephant conservation, since being identified as the cause of severe, often fatal, haemorrhagic disease in young Asian elephants. To describe positive cases and the molecular relatedness of virus detected in elephants in Thailand, we re-examined all available of EEHV samples occurring in young elephants in Thailand between 2006 and 2014 (n=24). Results indicated 75% (18/24) of suspected cases were positive for EEHV by semi-nested PCR. Further gene analysis identified these positive cases as EEHV1A (72%, 13/18 cases), EEHV1B (11%, 2/18) and EEHV4 (17%, 3/18). This study is the first to phylogenetically analyse and provide an overview of most of the known EEHV cases that have occurred in Thailand. Positive individuals ranged in age from one to nine years, with no sex association detected, and occurred across geographical locations throughout the country. All individuals, except one, were captive-born. No history of direct contact among the cases was recorded, and this together with the fact that various subtype clusters of virus were found, implied that none of the positive cases were epidemiologically related. These results concur with the hypothesis that EEHV1 is likely to be an ancient endogenous pathogen in Asian elephants. It is recommended that active surveillance and routine monitoring for EEHV should be undertaken in all elephant range countries, to gain a better understanding of the epidemiology, transmission and prevention of this disease.
大象嗜内皮细胞疱疹病毒（EEHV）正成为大象保护面临的新威胁，自其被确认为导致亚洲幼象严重且常致命的出血性疾病的病因以来。为描述泰国大象中检测到的病毒阳性病例及其分子相关性，我们重新检查了2006年至2014年间泰国幼象中所有可用的EEHV样本（n = 24）。结果表明，通过半巢式PCR，75%（18/24）的疑似病例EEHV呈阳性。进一步的基因分析将这些阳性病例鉴定为EEHV1A（72%，13/18例）、EEHV1B（11%，2/18）和EEHV4（17%，3/18）。本研究首次对泰国发生的大多数已知EEHV病例进行了系统发育分析并提供了概述。阳性个体年龄在1至9岁之间，未检测到性别关联，且分布在全国不同地理位置。除一例之外，所有个体均为圈养出生。病例之间未记录有直接接触史，再加上发现了病毒的各种亚型集群，这意味着所有阳性病例在流行病学上均无关联。这些结果与EEHV1可能是亚洲象古老的内源性病原体这一假设相符。建议在所有大象分布国家对EEHV进行主动监测和常规监测，以更好地了解这种疾病的流行病学、传播和预防情况。
