Infectious Salmon Anemia Virus

A small project about ISAVirus brought to you by a group of Year 2 MBIO students from Ngee Ann Polytechnic.

Click on the pastel orange box on the left for the names of the students involved in this project.

Thank you.

:)

Control Strategy
Thursday, 26 January 2012 @ 12:20
In the case of an outbreak of ISAV,
there would be several options to carry out at once, which are:

a) Destruction of the diseased fish
- Removing and disposing of the infected fish. This is of considerably high priority so as to keep the spreading and causing agents of the disease under control.

b) Quarantine
- Setting restrictions on the movement of fishes, materials, personnel and various equipments involved. This would thus require the affected area to be identified and disinfection of the personnel, equipments and discharged waste to be done.
c) Treatment of the affected fish population

Approaches to preventing spread and elimination of the pathogens:
  • Quarantine & movement controls


When implemented, practices to be considered includes
- live salmon transportation between and within freshwater and marine operations
- salmon harvesting and transportation to processing plants
- the discharge of salmon processing-plant wastes
- transportation of ready salmon consumer products
- the disposal of dead salmon
  • Establishing of quarantine areas


- Infected premises (where ISAV infection were identified)
- Restricted areas (in the vicinity of infected premises)
- Control area (the buffer between restricted premises and free areas)
- Free areas (areas not affected by the disease or unassessed yet)


After the quarantine areas are declared, factors to be accounted are the freshwater 
and marine phases of salmon production, movement of infected wild populations of rainbow trout and brown trout, the possibility of the existence or presence of an unknown susceptible species of wild fish that could be a carrier.




  • Movement controls include


- banning movement of live salmon out of affected areas
- banning movement of live salmon into areas free of the disease
- bans on releasing salmon into rivers or marine locations
- bans on movement of salmon between different river systems, between marine farm locations and freshwater farm locations
- bans on usage or movement of equipment between river systems and marine farms

  • Tracing of the disease


This is crucial in determining locations and causative agents of the disease and information derived will help to select the most appropriate response action to take. The following should be traced
- salmonids such as broodstock, smolts (a young salmon in the stage of its first migration to the sea), etc
- salmon products for human consumption
- water (inputs and outputs)
- vehicles, materials and personnel involved when the outbreak of disease occurred  

  • Surveillance is a must to find out the extent of the infection, detect new outbreaks, and also to monitor the progress and the successfulness of the strategy employed in eradicating the disease after which decontamination will then take place.
  • Disposal of diseased salmon

The fishes must be disposed of safely and effectively.  The best practice is to bury slaughtered animals on site but this is definitely not possible for diseased fish. Therefore, culled fish have to be transported to the site of burial or incineration safely without spreading the disease to other sites.

⚠ Public awareness
People should be informed that:
  1. humans will not be infected by ISAV
  2. consuming fishes with exposure to ISAV will not impose any health risks
  3. salmon or fishes that have died from the disease mustn’t be used as bait or made into feed for other aquatic animals
Diagnosis

Listed below are signs the diagnosis of ISAV is based on initially, before further isolation of the causative agent.

Clinical signs:
  • pale gills (sign of anaemia)
  • exophthalmia (protusion of eyeballs)
  • enlarged abdomen
  • the presence of skin haemorrhages (discharge of blood), especially at the abdomen
  • scale pocket oedema (swellings due to accumulation of fluid)
  • blood present in eye chamber


Behavioural changes to affected salmon
  • may appear lethargic and keep close to walls/ sides of the pen
  • loss of appetite
  • found gasping at surface of the water  
Gross Pathology
  • petechiae (pinpoint haemorrhages) in the skeletal muscles
  • oedema of the swim bladder (swelling)
  • accumulation of fluid in body cavity, could be bloody/ yellowish
  • ascites (enlarged abdomen due to fluids in peritoneal cavities)
  • swollen, dark red liver with possible thin fibrin layer
  • swollen, edges rounded, dark red spleen
  • congested, dark red kidney, with blood& liquid exuding out from cuts  
  • dark redness in the mucosa of the intestinal walls, with absence of blood in fresher specimens of the diseased fish
  • anaemia (deficiency of red blood cells)
References:

For Introduction, Life Cycle & Key Proteins:
Berit Lyng Schiøtz, Sven Martin Jørgensen, Caird Rexroad, Tor Gjøen, Aleksei Krasnov, June 2008. Transcriptomic analysis of responses to infectious salmon anemia virus infection in macrophage-like cells, Virus Research 136, pp. 65–74. Available through: Science Direct[Accessed on 22/01/2012]

Esther Garc´ıa-Rosado, Turhan Markussen, Øyvind Kileng, Espen S. Baekkevold, Børre Robertsen, Siri Mjaaland, Espen Rimstad, March 2008. Molecular and functional characterization of two infectious salmon anaemia virus (ISAV) proteins with type I interferon antagonizing activity, Virus Research 133, pp. 228–238. Available through: Science Direct[Accessed on: 14/01/2012]

Anita Müller, Turhan Markussen, Finn Drabløs, Tor Gjøen, Trond Ø. Jørgensen, Stein Tore Solem, Siri Mjaaland, April 2010. Structural and functional analysis of the hemagglutinin-esterase of infectious salmon anaemia virus, Virus Research 151, pp. 131–141. Available through Science Direct[ Accessed on 10/01/2012]

Knut Falk, Ellen Namork, Espen Rimstad, Siri Mjaaland, Birgit H. Dannevig, December 1997. Characterization of Infectious Salmon Anemia Virus, an Orthomyxo-Like Virus Isolated from Atlantic Salmon (Salmo salar L.), Journal of Virology, vol.71[12], pp. 9016-9023. Available through: NCBI[Accessed on 10/01/2012]

College of Veterinary Medicine Iowa State University, March 2010. Infectious Salmon Anemia(Hemorrhagic Kidney Syndrome). [Accessed on 22/01/2012]

Rahul Hate(Human Biology 115A), August 1999. Replication: Influenza Replication in Greater Detail. Available through: http://www.stanford.edu/group/virus/1999/rahul23/orthomyxoviridae.html [Accessed on 14/01/2012]

Picture for Life Cycle of Virus segment: From Robert A. Lamb and Robert M. Krug’s “Orthomyxoviridae: The Viruses and Their Replication,”in Fields Virology, Lippincott-Raven Publishers. 1996. P 1370. http://www.stanford.edu/group/virus/1999/rahul23/replication.html[Accessed on 14/01/2012]

Picture for Introduction segment: Swiss Institute of Bioinformatics, ViralZone 2009. Isavirus: Molecular Biology, Virion. Available through: http://viralzone.expasy.org/all_by_species/95.html[ Accessed on 22/01/2012]

Cartoon of ISAV: Gery Hummel, November 2011. Cartoon: ISAvirus Salmon. Available through: http://thecanadian.org/k2/item/1140-cartoon-isav-salmon[ Accessed on 22/01/2012]

Picture of Infected Salmon: Department of Inland Fisheries and Wildlife State of Maine, Fish Health Laboratory, November 2002. Infectious Salmon Anemia, volume 3[Issue 3]. Available through: http://www.maine.gov/ifw/fishing/health/vol3issue3.htm[Accessed on 22/01/2012]

Picture of Electron Microscopy of ISAV: Department of Inland Fisheries and Wildlife State of Maine, Fish Health Laboratory, November 2002. Infectious Salmon Anemia, volume 3[Issue 3]. Available through: http://www.maine.gov/ifw/fishing/health/vol3issue3.htm[Accessed on 22/01/2012]

Illustration of Atlantic Salmon Fish: Nicole D. Jamieson,Ted Walke, April 2007. Infectious Salmon Anemia Virus(ISAV). Available through: http://homepage.usask.ca/~vim458/virology/studpages2007/Nicole/isav.html, http://www.fish.state.pa.us/pafish/atlantic_salmon.jpg[Accessed on 22/01/2012]

For Distribution & Symptoms:
-5 January 2012, Infectious salmon anemia virus, UK. Retrieved 21 January 2012. From http://en.wikipedia.org/wiki/Infectious_salmon_anemia_virus
-8 December 2012, Infectious Salmon Anaemia, UK. Retrieved 21 January 2012. From http://en.wikivet.net/Infectious_Salmon_Anaemia
-The Centre for Food Security & Public Health, Institute For International Cooperation In Animal Biologics (March 2010), Infectious Salmon Anemia-Hemorrhagic Kidney Syndrome, Iowa State University, US. Retrieved 21 January 2012. From http://www.cfsph.iastate.edu/Factsheets/pdfs/infectious_salmon_anemia.pdf

for Control Strategy & Diagnosis:
I) Fisheries Research Services, (2009). Diagnosis of Infectious Salmon Anaemia (ISA), UK, Retrieved 22 Jan 2012, from http://www.scotland.gov.uk/Resource/Doc/1062/0076334.pdf
II) Department of Agriculture, Fisheries and Forestry (March 2009), Infectious Salmon Anaemia (Version 1.0). In: Australian Aquatic Veterinary Emergency Plan (AQUAVETPLAN), Australian Government Department of Agriculture, Fisheries and Forestry, Canberra, ACT, Retrieved 22 Jan 2012, from , Retrieved 22 Jan 2012, from http://www.daff.gov.au/__data/assets/pdf_file/0004/1038676/infectious-salmon-anaemia.pdf
III) World Organisation for Animal Health, (2009), Chapter 2.3.5. Infectious Salmon Anaemia. In: Manual of Diagnostic Tests for Aquatic Animals 2009, France, Retrieved 22 Jan 2012, from http://www.oie.int/fileadmin/Home/eng/Health_standards/aahm/2010/2.3.05_ISA%20.pdf


For Detection,vaccination & treatment of ISAV:


Khalid Munir, Frederick S.B Kibenge, April 2004.
Journal of Virological Methods (2004) Detection of infectious salmon anaemia virus by real-time RT–PCR
Available though: Science Direct [Accessed on 14/01/2012]

Jaime A. Tobar1*, Francisco C. Contreras1, Yelena Betz2, Catalina Bravo1, Mario Caruffo1, SofJerez1, Thomas Goodrich2, and Arun K. Dhar2. Oral vacciantion against Infectious Salmon Anemia in Atlantic Salmon (Salmon Salar) induces specific immunity and provides protection against infectious SAlmon Anemia Virus Challenge.
https://www.was.org/wasmeetings/meetings/ShowAbstract.aspx?Id=20064