What are the main pathogenic viruses of fish?

There are many pathogenic viruses in fish intended for human consumption or ornamental fish. They are found in both fresh water and sea water.

The detection of these viruses requires the use of laboratory analyzes (cell culture, immunology or molecular diagnosis).

Alloherpesviridae

Type: dsDNA (300 kbp)

Detection methods: Cytopathic effect, IFAT, PCR, qPCR

Virus and diseasesSpecies sensitiveSymptomsCyHV3 (= KHV): Koi herpesvirusKoi carp, common carpSkin discoloration, lethargy, loss of balance, hypertrophy and hypersecretion of mucus in the gill epithelium

Birnaviridae

Type: 2 dsRNA (5.7 kb)

Detection methods: IFAT, PCR

Virus and diseasesSusceptible speciesSymptomsIPNV: Infectious pancreatic necrosisMainly salmonidsSwimming, abdominal bulge, damage to the excretory tissue, necrosis of the exocrine pancreas, melanism, apathy, enteritisBirnavirus of the turbotTurbotApathy, hemorrhages, necrosis of the hematopoietic tissueBirnavirus of the leanLanApathy, hemorrhages, necrosis of hematopoietic tissue

Iridoviridae

Type: dsDNA (160 kbp)

Detection methods: IFAT, PCR

Viruses and diseasesSusceptible speciesSymptomsLymphocystivirusLymphocystic disease Sea bream, turbot, fish aquariumSkin tumors (giant cells)RanavirusEuropean catfish virusCatfishAscites, hemorrhages, necrosis of hematopoietic tissueEuropean sheatfish virusCatfishInappetence, melanism, abnormal swimming

Rhabdoviridae

Type: ssRNA(-) (11 kb)

Detection methods: IFAT, Sero-neutralization, PCR, qPCR

Virus and diseasesSensitive speciesSymptomsNovirhabdovirusVHSV: Viral hemorrhagic septicemiaTrout (rainbow and brown), turbot, whitefish, pike, char, black bassMelanism, exophthalmos, anemia, hemorrhages, ascites, nervous symptoms, hematopoietic necrosis (kidney, spleen)IHNV: Infectious hematopoietic necrosisRainbow trout, salmonMelanism, exophthalmos, anemia, hemorrhages, ascites, nervous symptoms, hematopoietic necrosis (kidney, spleen)VesiculovirusSVCV: Spring carp viremiaCarp, catfishMelanism, exophthalmos, anemia, hemorrhages, ascites, nervous symptoms, necrosis hematopoietic (kidney, spleen)PFR: Red disease of pike fryPikeMelanism, exophthalmia, anemia, hemorrhages, ascites, nervous symptoms, hematopoietic necrosis (kidney, spleen)PRhV: Rhabdovirus disease of perchPerch, zanderMelanism, exophthalmos, anemia, hemorrhages, ascites, nervous symptoms, hematopoietic necrosis (kidney, rate)

Nodaviridae

Type: 2 ssRNA(+) (4.5 kb)

Detection methods: IFAT, PCR, qPCR

Virus and diseasesSensitive speciesSymptomsBetanodavirusVER or VNN: Encephalopathy, Viral retinopathyBar, turbot, seaweed, lean, sea bream, sole, halibut, grouper, tilapia, guppyNervous signs, inappetence, abnormal swimming, loss of balance, nerve damage (vacuolization)

Togaviridae

Type: ssRNA(+) (12 kb)

Detection methods: IFAT, PCR

Virus and diseasesSusceptible speciesSymptomsSAV16: Sleeping sickness, sleeping sickness pancreasRainbow trout, Atlantic salmon, brown troutFish lying on their sides, necrosis of the exocrine pancreas, heart and muscle damage, inappetence, apathy

Orthomyxoviridae

Type: 8 ssRNA(–) (13.5 kb)

Detection methods: IFAT, PCR

Virus and diseasesSusceptible speciesSymptomsISAV: Infectious salmon anemiaAtlantic salmonSevere anemia, exophthalmos, ascites, petechiae in the abdominal fat, congestion of the liver and spleen, liver very dark in color