Recent developments in the study and surveillance of koi herpesvirus (KHV) in Asia
EXTERNAL LINKS DISCLAIMER
This link is being provided as a convenience and for informational purposes only. SEAFDEC/AQD bears no responsibility for the accuracy, legality or content of the external site or for that of subsequent links. Contact the external site for answers to questions regarding its content.
If you come across any external links that don't work, we would be grateful if you could report them to the repository administrators.
Request this document in case the link we provided don't work.
Click Download to open/view the file.
MetadataShow full item record
PublisherFish Health Section, Asian Fisheries Society
Showing items related by title, author, creator and subject.
Conference paperGD Lio-Po - In Proceedings of the 1st International Congress on Aquatic Animal Health Management and Diseases, 27-28 January 2009, 2009 - Veteran Council I.R.IRANIn Southeast Asia, the Viral Nervous Necrosis (VNN) or Viral Encephalopathy and Retinopathy (VER) and the Koi herpesvirus (KHV) infection are currently economically-important diseases of fishes. The VNN affects groupers (Epinephelus akaara, E. coioides, E. tauvina, E. fuscogutatus, E. septemfasciatus, E. malabaricus, E. moara and Cromileptes altivelis), Asian sea bass (Lates calcarifer), mangrove red snapper (Lutjanus argentimaculatus) and milkfish (Chanos chanos) in Thailand, Taiwan, Indonesia, Brunei, Malaysia, Singapore, Philippines and Vietnam. The Piscine nodavirus of the genus Betanodavirus, genotype red-spotted grouper nervous necrosis virus (RGNNV) is predominantly involved. Research on fish species pathogenicity, optimum temperature, cell susceptibility, organ predeliction, pathology, virus reservoirs, experimental infection, vaccination and diagnosis have been reported. The Koi herpesvirus (KHV) infection causes significant mortalities in common carp (Cyprinus carpio carpio), koi carp (Cyprinus carpio koi) and ghost carp (common x koi cross, Cyprinus carpio goi). Outbreaks have been reported among koi in Hongkong in 2001; common carp in Indonesia, in 2002; koi in Taiwan in 2002; and common carp in Japan, in 2003. A dramatic spread of the disease was subsequently observed among most prefectures in Japan, with outbreaks that eventually involved koi carp. In Thailand, KHV was first diagnosed in March 2005 while in Singapore, in Sept 2005. By Feb 2006, two batches of Thai koi exported to Singapore, tested KHV PCR positive from which the virus was successfully isolated on KF-1 cells. In Malaysia, no KHV outbreak was reported but the presence of the virus was detected among koi carp exported to UK in 2000 and in 2001. In 2004, koi carp in Malaysia tested positive for KHV by nested PCR. To date, annual active surveillance of the virus in Cambodia, Lao PDR, Myanmar, Philippines and Vietnam from 2004 to 2008 showed these countries are free of KHV. Recent developments on research of KHV focused on pathogenicity, cell line susceptibility, fish size susceptibility, predilection to fish organs, persistence in fish, vaccine development and application, surveillance and gene sequence analyses of KHV strains. The extensive international trading of live ornamental koi fish has largely contributed to the global spread of KHV. Hence, KHV was recently added to the list of notifiable diseases to the World Organisation of Animal Health or the Office International des Epizooties (OIE).
ArticleJ Kurita, K Yuasa, T Ito, M Sano, RP Hedrick, MY Engelsma, OLM Haenen, A Sunarto, EB Kholidin, HY Chou, MC Tung, L de la Peña, G Lio-Po, C Tu, K Way & T Iida -
Fish Pathology, 2009 - Japanese Society of Fish PathologyThree regions of koi herpesvirus (KHV) genomic DNA were compared for 34 samples from Japan, six from Indonesia, two from Taiwan, one from the Philippines, 13 from the Netherlands, one from the UK, one from the USA and one from Israel. The analyzed genomic regions included known PCR-detection targets (SphI-5, 9/5 and the thymidine kinase gene). The KHVs from Asian countries were very homogeneous, although two variants were noted based on a single nucleotide polymorphism. In contrast, seven variants were found in KHVs from outside of Asia, and although closely related to one another, they were clearly distinct from those from Asian. The results suggest that a clear genetic distinction exists between Asian and European (including each single isolate from the USA and Israel) types of KHV, and that unique types of KHV were independently introduced or emerged in the respective geographic locations.
Conference paperC Tu, SY Lin & HT Sung - In CR Lavilla-Pitogo & K Nagasawa (Eds.), Transboundary Fish Diseases in Southeast Asia: Occurence, Surveillance, Research and Training. Proceedings of … Diseases in Southeast Asia: Occurence, Surveillance, Research and Training, Manila, Philippines, 23-24 June 2004, 2004 - SEAFDEC Aquaculture DepartmentThe first reported case of koi herpesvirus disease (KHVD) occurred in northern Taiwan in December 2002. Later, there were three more cases in 2003 and one outbreak of KHVD in 2004. Externally, the affected fish did not show any prominent lesions except swollen gills sometimes accompanied by bleeding. Consistent histopathological findings were in the gill tissues, where hyperplasic epithelia and eosinophilic granular cells were observed within fused secondary lamellae. Electron microscopy revealed negativelystained icosahedral viral nucleocapsids measuring 112±1 nm in diameter. Also, the koi herpesvirus was detected in the homogenate of diseased fish by PCR assay using specific primers for koi herpesvirus (KHV). The amplicon was cloned, sequenced and compared with previously published data. The sequenced data showed 99% identity with the American KHV sequence in the GenBank. The above evidence suggests that KHVD have already invaded carp culture systems in Taiwan.