Graduate Program in Animal Health and Biomedical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
Department of Veterinary Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
J Fish Dis. 2019 Sep;42(9):1293-1300. doi: 10.1111/jfd.13050. Epub 2019 Jun 27.
Tilapia lake virus disease (TiLVD) is an emerging viral disease in tilapia with worldwide distribution. Although the horizontal transmission of TiLV has been demonstrated through the cohabitation of infected fish with susceptible fish, no direct experiment showed the potential of vertical transmission from broodstock to progeny. In this study, natural outbreaks of TiLV in broodstock and fry in two tilapia hatcheries were confirmed. The TiLV genomic RNA was detected in liver and reproductive organs of infected broodstock, while infective virus was isolated in susceptible cell line. In situ hybridization assay confirmed the presence of TiLV in the ovary and testis of naturally infected fish and experimentally challenged fish. Moreover, early detection of TiLV in 2-day-old fry and the presence of TiLV genomic RNA and viable virus in the testis and ovary suggested the possible transfer of this virus from infected broodstock to progenies. As infective virus was present in gonads and fry in natural outbreak and experimental fish, the importance of biosecurity and prevention of the virus to establish in the hatchery should be emphasized. Hence, the development of TiLV-free broodstock and the maintenance of high biosecurity standards in the hatcheries are essential for any attempt of virus eradication.
罗非鱼湖病毒病（TiLVD）是一种在罗非鱼中流行的新兴病毒性疾病，分布于全球各地。尽管已经证明通过感染鱼与易感鱼共养可以实现 TiLV 的水平传播，但没有直接的实验表明亲鱼向后代垂直传播的潜力。本研究证实了两个罗非鱼孵化场亲鱼和鱼苗中 TiLV 的自然爆发。在感染的亲鱼的肝脏和生殖器官中检测到 TiLV 基因组 RNA，而在易感细胞系中分离到感染性病毒。原位杂交检测证实了自然感染鱼和实验感染鱼的卵巢和睾丸中存在 TiLV。此外，在 2 日龄鱼苗中早期检测到 TiLV，以及在睾丸和卵巢中存在 TiLV 基因组 RNA 和有活力的病毒，提示该病毒可能从感染的亲鱼转移到后代。由于在自然爆发和实验鱼中，感染性病毒存在于性腺和鱼苗中，因此应该强调在孵化场进行生物安全和预防病毒建立的重要性。因此，开发无 TiLV 的亲鱼和在孵化场维持高生物安全标准对于任何病毒根除尝试都是必要的。
