Poster 1: Infectious Hematopoietic Necrosis Virus

Question 1

What is IHNV?

Answer 1

• acute systemic viral disease that affects wild and farmed salmon
• Rhabdovirus - a negative sense, single stranded RNA virus
• enveloped bullet shaped virus particle
• three different genotypes: U, M, and L

Question 2

Where is it found?

Answer 2

• includes North America, Europe and Asia
• not the Southern Hemisphere
• enzootic to areas of west coast of Northern hemisphere

Question 3

What are the clinical signs

Answer 3

• lethargic and anorexic
• swim high in water
• darkening of body colour
• distended abdomen
• pale gills
• hemorrhages at base of fins
• spinal deformities in surviving salmon
• necrosis of kidney, spleen, liver and pancreas

Question 4

Modes of transmission

Answer 4

• commonly shed through external mucous, or ovarian and seminal fluid of fish during spawning
• waterborne horizontal transmission can also occur in both fresh and seawater

Question 5

Mechanism of action

Answer 5

• attachment of viral G glycoproteins to host cell receptors enables clathrin mediated endocytosis of virus into host cell
• viral membrane fuses with the vesicle membrane and ribonucleocapsids are released into cytoplasm
• transcription, translation and replication all occur in cytoplasm
• budding of the virus occurs through viral recruitment of host ESCRT complexes, cleaving virus from host cell