| Salmonid herpesvirus 3 | |
|---|---|
Virus classification 
| |
| (unranked): | Virus |
| Realm: | Duplodnaviria |
| Kingdom: | Heunggongvirae |
| Phylum: | Peploviricota |
| Class: | Herviviricetes |
| Order: | Herpesvirales |
| Family: | Alloherpesviridae |
| Genus: | Salmonivirus |
| Species: | Salmonid herpesvirus 3
|
| Synonyms | |
| |
Salmonid herpesvirus 3 (SalHV-3) is a species of virus in the genus Salmonivirus, family Alloherpesviridae, and order Herpesvirales.[1]
The virus has been referred to as epizootic epitheliotrophic disease virus (EEDV) after the disease caused by the virus was first referred to as epizootic epitheliotrophic disease (EED) in 1989.[2]
Salmonid herpesvirus 3 affects lake trout (Salvelinus namaycush), resulting in several mass mortality events over the years.[2]
Background[edit]
The virus was initially identified in 1988 when investigating the cause behind the mass mortalities of cultured juvenile lake trout within two hatcheries located in the Great Lakes region of the United States.[3] By the end of the 1980s, 15 million lake trout had died due to the virus in the Laurentian Great Lakes Basin.[4][5] Hatcheries removed the infected fish and heavily sanitized the contaminated areas in order to prevent further spread of the virus. However, a northern Michigan hatchery experienced two outbreaks in 2012 and 2017, resulting in the loss of approximately 100,000 lake trout, indicating that the threat of Salmonid herpesvirus 3 is still present, possibly due to infected wild lake trout being introduced to the hatcheries for breeding.[4]
Pathology[edit]
Salmonid herpesvirus 3 has been found to target skin cells more than other external and internal tissue of the fish.[6] In the early stages of infection, the cells of the epithelium are most affected, while gills harbour less copies of the virus than other external areas of the body. Viral DNA has not been found to be present in the internal organs until at least two weeks post-infection.[4] As the disease progresses, the skin of the fish is shed, leading researchers to believe the ulcerated, necrotic tissue of infected fish being the primary source of infection to neighbouring fish. Skin, eye, and gill tissue contain a higher amount of virus-positive DNA than internal organ tissue throughout all stages of infection.
Clinical signs indicating infection of the virus include fin congestion, corneal opacity, skin lesions (including ulceration), gill pallor, and erythema.[4]
PCR and qPCR assays have been developed in order to detect the presence of the virus during active viral outbreaks and latent states of infection in lake trout from kidney, skin, ovarian fluid. The earliest detection of the virus in infected fish was experimentally found to be by day 9.[7]
Treatment[edit]
There are currently no treatments or vaccines for Salmonid herpesvirus-3, however prevention measures such as the usage of potassium peroxymonosulfate (PPMS)-based disinfectants on hatchery tools have been utilized to minimize loss of hatchery-raised lake trout.[8]
References[edit]
- ^ "ICTV Master Species List 2018b.v2". International Committee on Taxonomy of Viruses (ICTV). Archived from the original on March 30, 2019. Retrieved 19 June 2019.
- ^ a b Bradley, T. M.; Medina, D. J.; Chang, P. W.; McClain, J. (1989). "Epizootic Epitheliotropic Disease of lake trout (Salvelinus namaycush): history and viral etiology" (PDF). Diseases of Aquatic Organisms. 7 (4): 195–201. doi:10.3354/dao007195. ISSN 0177-5103.
- ^ Bradley, T. M.; Newcomer, C. E.; Maxwell, K. O. (1988). "Epitheliocystis associated with massive mortalities of cultured lake trout Saivelinus namaycush" (PDF). Diseases of Aquatic Organisms. 4 (1): 9–17. doi:10.3354/dao004009. ISSN 0177-5103.
- ^ a b c d Shavalier, M.; Faisal, M.; Loch, T. P.; Fitzgerald, S. D.; Thaiwong, T.; Kiupel, M. (2020). "Disease progression in Lake Trout (Salvelinus Namaycush) experimentally infected with epizootic epitheliotropic disease virus (salmonid herpesvirus-3)". Veterinary Pathology. 57 (5): 687–699. doi:10.1177/0300985820941268. ISSN 0300-9858. PMID 32744164.
- ^ McAllister, P. E.; Herman, R. L. (1989). "Epizootic mortality in hatchery-reared lake trout Salvelinus namaycush caused by a putative virus possibly of the herpesvirus group" (PDF). Diseases of Aquatic Organisms. 6 (2): 113–119. doi:10.3354/dao006113. ISSN 0177-5103.
- ^ Faisal, M.; Purbayu, M.; Shavalier, M. A.; Marsh, T. L.; Loch, T. P. (2019). "Shedding of the salmonid herpesvirus-3 by infected lake trout (Salvelinus namaycush)". Viruses. 11 (7): 580. doi:10.3390/v11070580. ISSN 1999-4915. PMC 6669692. PMID 31247927.
- ^ Glenney, G. W.; Barbash, P. A.; Coll, J. A. (2016). "A quantitative polymerase chain reaction assay for the detection and quantification of epizootic epitheliotropic disease virus (EEDV; salmonid herpesvirus 3)". Journal of Aquatic Animal Health. 28 (1): 56–67. Bibcode:2016JAqAH..28...56G. doi:10.1080/08997659.2015.1121935. ISSN 0899-7659. PMID 26980561.
- ^ Purbayu, M. A.; Shavalier, M. A.; Faisal, M.; Loch, T. P. (2021). "Experimental evidence of epizootic epitheliotropic disease virus (salmoid herpesvirus-3, Alloherpesviridae) transmission via contaminated fomites and subsequent prevention using a disinfectant". Pathogens. 10 (6): 724. doi:10.3390/pathogens10060724. ISSN 2076-0817. PMC 8227329. PMID 34207532.
