Viral hemorrhagic septicemia

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Viral hemorrhagic septicemia

The viral haemorrhagic septicemia (VHS) is one with bleeding associated (bleeding) in the organs viral disease , which mainly trout fish (salmon), but also affects other species. She is one of the notifiable animal diseases . The causative agent is a rhabdovirus (VHSV).

Pathogen

Viral Hemorrhagic Septicemia Virus
VHSV.jpg

Electron microscopic negative
image of the Piscine novirhabdovirus

Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Negarnaviricota
Subphylum : Haploviricotina
Class : Monjiviricetes
Order : Mononegavirals
Family : Rhabdoviridae
Genre : Novirhabdovirus
Type : Viral Hemorrhagic Septicemia Virus
Taxonomic characteristics
Genome : (-) ssRNA linearly unsegmented
Baltimore : Group 5
Symmetry : helical
Cover : available
Scientific name
Piscine novirhabdovirus
Short name
VHSV
Left

Viral haemorrhagic septicemia (VHS) by the Piscine novirhabdovirus (formerly Viral hemorrhagic Septikämievirus , English Viral hemorrhagic septicemia virus causes VHSV). It infects over 50 species of freshwater and marine fish in several parts of the northern hemisphere. Different strains of the virus occur in different regions and in different host species. There is no evidence that the disease is affecting human health. VHS is also known as Egtved disease, and the virus is known as Egtved virus .

VHSV is a species of single-stranded RNA viruses of negative polarity in the order Mononegavirales , family Rhabdoviridae , and genus Novirhabdovirus . A further related fish rhabdovirus species is the Salmonid novirhabdovirus (obsolete Infectious hematopoietic necrosis virus , Infectious hematopoietic necrosis virus , type IHNV species in the genus Novirhabdovirus ), which in salmon ( Salmonidae causes infectious hematopoietic) necrosis (IHN).

The viral cause of the disease was discovered by MH Jenson in 1963. The virions (virus particles) of VHSV are enveloped, spherical (spherical), about 180  nm long, with a diameter of about 60 nm, covered with 5 to 15 nm long peplomers .

Epizootiology

The disease occurs most acutely in rainbow trout and pike , other trout fish are usually only infected without symptoms. It is important for the control that fish that survive the disease and infected fish without symptoms remain virus carriers for life and thus represent a reservoir of pathogens. The transmission takes place via contaminated water, infected fish and waterfowl, but also equipment and staff from pond farms .

Subtypes

Different isolates (isolable strains) of VHSV are usually grouped based on their genotype . A grouping according to the geography of occurrence appears to be more expedient for this species than according to host species. Previous studies used different naming systems, but now the following system has become common. This is based on the similarity of the genotype (determined by sequence analysis of the N and G genes ). Types I-III are enzootic in Europe and type IV in North America . Types I and IV are further subdivided as follows:

Type Dominant host type and location
  Yes Breeding facilities for rainbow trout and some other freshwater fish in continental Europe
  Ib Saltwater fish of the Baltic Sea , Skagerrak , Kattegat , North Sea , Japan
  Ic Rainbow trout farms in Denmark
  Id Rainbow trout farms in Norway , Finland and the Gulf of Bothnia
  Ie Rainbow trout in Georgia , farmed and wild turbot in the Black Sea
  II Saltwater fish of the Baltic Sea
  III Saltwater fish from the British Isles and Northern France , farmed turbot in Great Britain and Ireland, and black halibut ( Reinhardtius hippoglossoides ) in Greenland .

Breeding rainbow trout in Norway.

  IV-a Saltwater fish of the Northwest Pacific ( North America ), the North American North Atlantic coast , Japan and Korea
  IV-b Freshwater fish in the North American Great Lakes region

The first strain discovered was Type Ia in 1963, and the second did not follow until the end of 1988. Ia was isolated from fish farms in continental Europe and mainly affected rainbow trout, occasionally brown trout or pike.

In 1988, the first marine strain of VHSV, now referred to as Type IV, was found in normal-appearing salmon as they returned to the rivers of Washington state from the Pacific. This strain and other marine strains were not fatal to rainbow trout. The discovery led to further investigation, and in the mid-1990s marine VHSV was found in eight species along the North American Pacific coast and in 14 species in and around the Atlantic North Sea. In 1996, VHSV was first found in Japan in Japanese flounder ( Paralichthys olivaceus ) that were bred in the Seto Inland Sea . Since then, different genotypes have appeared in different areas. Type IV was later found off the North American Atlantic coast in the Atlantic herring ( Clupea harengus ), the mummichog ( Fundulus heteroclitus ), the three- spined stickleback ( Gasterosteus aculeatus aculeatus ), the brown trout ( Salmo trutta ) and the striped bass ( Morone saxatilis ). There are also dozens of species of freshwater fish in the Great Lakes.

Since then, VHSV has been found in other geographical areas and in other fish species. It is believed that this is caused by both the spread of the virus to new areas through VHSV infected eggs and live fish transfers from North America to Asia, as well as feeding raw sea fish to domestically raised trout (as in Finland). Another possibility is the discovery of pre-existing populations, such as what appears to be a well-established marine reservoir in the Black Sea.

To keep track of the distribution of the various VHSV genotypes, a database called Fishpathogens.eu was created, which stores data on various fish pathogens (including VHSV) and their sequences.

Symptoms

The VHS can occur in various clinical pictures.

The acute form is characterized by sudden mass deaths. The fish are apathetic, dark in color, have pale gills and protruding eyeballs ( exophthalmos ). Pathological-anatomically, there are punctual bleeding in the muscles , skin , eyes and internal organs as well as enteritis , recognizable by a filling of the intestine with yellow mucus.

The chronic form follows the acute form. Symptoms are similar, but the number of deaths is low.

In the nervous form , there are hardly any deaths and the classic symptoms are also absent. Instead, the fish show signs of central nervous system disorder such as imbalance and abnormal swimming movements.

Legal basis

In Germany, the measures to combat VHS are regulated by:

proof

In a suspected case, virological diagnostics are required by law for definitive proof of the disease . It is done by growing the virus in a cell culture and detecting it using VHS antibodies . It is also possible to detect virus ribonucleic acid by means of polymerase chain reaction (PCR).

Individual evidence

  1. ICTV Master Species List 2018b.v2 . MSL # 34, March 2019
  2. a b ICTV: ICTV Taxonomy history: Akabane orthobunyavirus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. a b c Disease Factsheets: Viral Hemorrhagic Septicemia Iowa State University, The Center for Food Security & Public Health. Last updated May 17, 2007. Retrieved July 12, 2007.
  4. ^ A b McAllister, Philip E .: Fish Disease Leaflet 83: Viral Hemorrhagic Septicemia of Fishes . United States Department of the Interior, US Fish and Wildlife Service. 1990. Retrieved July 12, 2007.
  5. NCBI Taxonomy browser (Viral hemorrhagic septicemia virus). NCBI Taxonomy Database. United States Department of Health and Human Services, National Institutes of Health, National Library of Medicine, National Center for Biotechnology Information. Retrieved July 14, 2007.
  6. Kipp, Rebekah M., Anthony Ricciardi: VHS Factsheet . 2006-12-08. Retrieved July 16, 2007.
  7. a b T Nishizawa, H Iida, R Takano, T Isshiki, K Nakajima, K Muroga: Genetic relatedness among Japanese, American and European isolates of viral hemorrhagic septicemia virus (VHSV) based on partial G and P genes . In: Diseases of Aquatic Organisms . 48, No. 2, 2002, pp. 143-8. doi : 10.3354 / dao048143 . PMID 12005236 .
  8. ^ R Thiéry, C De Boisséson, J Jeffroy, J Castric, P De Kinkelin, A Benmansour: Phylogenetic analysis of viral haemorrhagic septicaemia virus (VHSV) isolates from France (1971-1999) . In: Diseases of Aquatic Organisms . 52, No. 1, 2002, pp. 29-37. doi : 10.3354 / dao052029 . PMID 12517003 .
  9. a b K. Eine -Jensen: Evolution of the fish rhabdovirus viral haemorrhagic septicaemia virus . In: Journal of General Virology . 85, No. 5, 2004, pp. 1167-79. doi : 10.1099 / vir.0.79820-0 .
  10. a b T. Nishizawa, H. Savas, H. Isidan, C. Ustundag, H. Iwamoto, M. Yoshimizu: Genotyping and Pathogenicity of Viral Hemorrhagic Septicemia Virus from Free-Living Turbot (Psetta maxima) in a Turkish Coastal Area of the Black Sea . In: Applied and Environmental Microbiology . 72, No. 4, 2006, pp. 2373-8. doi : 10.1128 / AEM.72.4.2373-2378.2006 . PMID 16597932 . PMC 1449023 (free full text).
  11. a b N Gagné, AM MacKinnon, L Boston, B Souter, M Cook-Versloot, S Griffiths, G Olivier: Isolation of viral haemorrhagic septicaemia virus from mummichog, stickleback, striped bass and brown trout in eastern Canada . In: Journal of Fish Diseases . 30, No. 4, 2007, pp. 213-23. doi : 10.1111 / j.1365-2761.2007.00802.x . PMID 17394523 .
  12. OB Dale, I Ørpetveit, TM Lyngstad, S Kahns, HF Skall, NJ Olesen, BH Dannevig: Outbreak of viral haemorrhagic septicaemia (VHS) in seawater-farmed rainbow trout in Norway caused by VHS virus Genotype III . In: Diseases of Aquatic Organisms . 85, No. 2, 2007, pp. 93-103. doi : 10.3354 / dao02065 . PMID 19694169 .
  13. ICES. Report of the ICES Advisory Committee on Fishery Management, Advisory Committee on the Marine Environment and Advisory Committee on Ecosystems, 2006. 2006. ICES Advice. Books 1 - 10. 1.68 pp.
  14. ^ A b Whelan, Gary E. Viral Hemorrhagic Septicemia (VHS) Briefing Paper . Michigan Department of Natural Resources. 2007-02-26. Retrieved July 13, 2007.
  15. Crane, M. Chapter 2.1.5: Viral Hemorrhagic Septicemia Manual of Diagnostic Tests for Aquatic animals 2006. Retrieved July 16, 2007.
  16. Importation of pilchards (Sardinops sagax) for direct introduction into natural waters: Biosecurity policy review of viral haemorrhagic septicaemia virus (VHSV), Draft Report, June 2003 . Commonwealth of Australia. 2003. Retrieved July 16, 2007.
  17. T Isshiki, T Nishizawa, T Kobayashi, T Nagano, T Miyazaki: An outbreak of VHSV (viral hemorrhagic septicemia virus) infection in farmed Japanese flounder Paralichthys olivaceus in Japan . In: Diseases of Aquatic Organisms . 47, No. 2, 2001, pp. 87-99. doi : 10.3354 / dao047087 . PMID 11775799 .
  18. ^ E Elsayed, M Faisal, M Thomas, G Whelan, W Batts, J Winton: Isolation of viral haemorrhagic septicaemia virus from muskellunge, Esox masquinongy (Mitchill), in Lake St Clair, Michigan, USA reveals a new sublineage of the North American genotype . In: Journal of Fish Diseases . 29, No. 10, 2006, pp. 611-9. doi : 10.1111 / j.1365-2761.2006.00755.x . PMID 17026670 .
  19. ^ European Union Reference Laboratory for Fish Diseases Fish Pathogens Database .
  20. Fish Disease Ordinance