National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand.
J Fish Dis. 2010 May;33(5):421-30. doi: 10.1111/j.1365-2761.2009.01135.x. Epub 2010 Feb 10.
Yellow head virus (YHV) is known as a major pathogen in the black tiger shrimp, Penaeus (Penaeus) monodon. It can also cause serious mortality in farmed whiteleg shrimp, Penaeus (Litopenaeus) vannamei. However, there is no published information on the economic and/or production impact of the disease in P. vannamei. Shrimp with gross signs of YHV disease (faded body colour and 60-70% mortality) were observed in 20 study farms rearing P. vannamei in the central part of Thailand from the end of 2007 through early 2008. The estimated economic loss for these farms according to the Thai Animal Aquaculture Association was approximately US$3 million. Detailed sequence analysis of RT-PCR amplicons from shrimp in all the study ponds revealed the presence of YHV Type 1b (YHV-1b) alone (characterized by a 162-bp deletion in the ORF3 region encoding the structural gene for gp116) and the absence of YHV Type 1a (YHV-1a), the original YHV type reported from Thailand. Despite the large 162-bp deletion (= 54 deduced amino acids) in the gp116 structural gene, histopathology of YHV-1b infections was identical to that of YHV-1a infections, and electron microscopy revealed that YHV-1b virions were morphologically indistinguishable from those previously reported for YHV-1a. In addition, an existing commercial RT-PCR detection kit and an immunochromatographic test strip for the detection of YHV were proven to have been valid tests for both YHV-1b and YHV-1a. The source of the virus for these outbreaks was unlikely to have been the post-larvae used to stock the ponds, as they were derived from domesticated specific pathogen-free stocks free of YHV. Thus, it is possible that they originated from an unknown, natural reservoir.
黄头病毒（YHV）是黑虎虾（Penaeus monodon）的主要病原体，也可导致养殖白对虾（Penaeus vannamei）严重死亡。然而，目前尚无关于该病对 P. vannamei 经济和/或生产影响的公开信息。2007 年底至 2008 年初，在泰国中部的 20 个养殖 P. vannamei 的研究养殖场中，观察到有 YHV 疾病明显症状（体色褪色和 60-70%死亡率）的虾。根据泰国动物水产养殖协会的估计，这些养殖场的经济损失约为 300 万美元。对所有研究池塘中虾的 RT-PCR 扩增子进行详细序列分析表明，仅存在 YHV 1b 型（YHV-1b）（其 ORF3 区域编码 gp116 结构基因的 162-bp 缺失），而不存在 YHV 1a 型（YHV-1a），即泰国最初报告的 YHV 型。尽管 gp116 结构基因中有一个 162-bp 的大缺失（=54 个推导的氨基酸），但 YHV-1b 感染的组织病理学与 YHV-1a 感染相同，电子显微镜显示 YHV-1b 病毒粒子在形态上与之前报道的 YHV-1a 病毒粒子无法区分。此外，现有的商业 RT-PCR 检测试剂盒和用于检测 YHV 的免疫层析测试条已被证明对 YHV-1b 和 YHV-1a 均为有效检测方法。这些暴发的病毒来源不太可能是用于养殖池塘的幼虾，因为它们源自无 YHV 的驯化无特定病原体种群。因此，它们有可能来自未知的天然宿主。
