Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Emerging and Re-emerging Infectious Diseases in Animals (CUEIDAs), Center of Excellence, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Transbound Emerg Dis. 2018 Oct;65(5):1208-1216. doi: 10.1111/tbed.12859. Epub 2018 Mar 8.
Duck Tembusu virus (DTMUV), a newly emerging virus in ducks, was first reported in China in 2010. However, an unknown severe contagious disease associated with severe neurological signs and egg production losses in ducks, resembling to DTMUV infection, was observed in Thailand since 2007. To determine the presence of DTMUV in 2007, the clinical samples from affected ducks collected in 2007 were tested for DTMUV using pathological and virological analyses. Gross and histopathological lesions of affected ducks were mostly restricted to the ovary, brain and spinal cord, and correlated with the presence of flavivirus antigen in the brain and spinal cord samples. Subsequently, DTMUV was identified by RT-PCR and nucleotide sequencing of the polyprotein gene. Phylogenetic analysis of the polyprotein gene sequence revealed that the 2007 Thai DTMUV was a unique virus, belonged within DTMUV cluster 1, but distinctively separated from the Malaysian DTMUV, which was the most closely related DTMUV. It is interesting to note that the 2007 Thai DTMUV was genetically different from the currently circulating Thai and Chinese DTMUVs, which belonged to cluster 2. Our findings indicated that the 2007 Thai DTMUV emerged earlier from a common ancestor with the recently reported DTMUVs; however, it was genetically distinctive to any of the currently circulating DTMUVs. In conclusion, our data demonstrated the presence of DTMUV in the Thai ducks since 2007, prior to the first report of DTMUV in China in 2010. This study indicates that DTMUV may have circulated in the region long before 2010 and highlights high genetic diversity of DTMUVs in Asia.
鸭坦布苏病毒（DTMUV）是一种在鸭群中新兴的病毒，于 2010 年在中国首次报道。然而，自 2007 年以来，泰国一直在观察到一种与 DTMUV 感染类似的、与严重神经症状和产蛋损失相关的未知传染性极强的疾病。为了确定 2007 年是否存在 DTMUV，使用病理学和病毒学分析检测了 2007 年从患病鸭收集的临床样本中是否存在 DTMUV。患病鸭的大体和组织病理学病变主要局限于卵巢、脑和脊髓，与脑和脊髓样本中黄病毒抗原的存在相关。随后，通过 RT-PCR 和多蛋白基因的核苷酸测序鉴定了 DTMUV。多蛋白基因序列的系统进化分析显示，2007 年泰国 DTMUV 是一种独特的病毒，属于 DTMUV 簇 1，但与马来西亚 DTMUV 明显分离，马来西亚 DTMUV 是最密切相关的 DTMUV。有趣的是，2007 年泰国 DTMUV 在遗传上与目前流行的泰国和中国 DTMUV 不同，后者属于簇 2。我们的研究结果表明，2007 年泰国 DTMUV 从一个与最近报道的 DTMUV 相同的共同祖先中更早出现，但在遗传上与任何目前流行的 DTMUV 都不同。总之，我们的数据表明，2007 年泰国鸭群中就存在 DTMUV，早于 2010 年中国首次报道 DTMUV。本研究表明，DTMUV 可能在 2010 年之前就在该地区传播，突显了亚洲 DTMUV 高度的遗传多样性。
