GCRV (Grass Carp Reovirus)

TRANSMISSION

member of the genus Aquareovirus

Average diameter 69 mm

Isohedral in shape

Found in the inclusion bodies of the nucleus or cytoplasm
Not found in red cells or granular white cells
Sensitive to either acid and alkali

Incentive to drugs of the tetracycline family

high resistance to heat

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Horizontal: (Water borne or through ectoparasites

Not zoonotic: cannot be transmitted to humans

TEMPERATURE

optimum 25-28°C

HOST RANGE

Black carp

Topmouth gudgeon

Grass carp

CLINICAL SYMPTOMS

External

Internal

🚩Body become dark and slightly red
🚩hypodermic
🚩hyperemia in juveniles
🚩hemorrhages at the base of fins, gills covers and mouth cavity

🏁 hemorrhages throughout the musculature
🏁Red intestine
🏁Hemorrhagic gills or pale gills
🏁Hemorrhages in organs such as liver, spleen, kidney and intestine

DIAGNOSIS

Virus identification
💚neutralization test
💚ELISA
💚RT-PCR

Primary diagnosis


✅internal
✅external
✅isolation of the virus from infected fish by cell culture

TREATMENTS & CONTROL

❤Destructions of pathogens
❤Destructions of fish parasites
❤Depopulation
❤Use of virus free water
❤Disinfections of tools
❤Effective vaccination

VACCINE PREPARATION

1) Organs such as liver, spleen, and kidney from infected grass carp are collected and homogenized

2)Diluted with 0.85% NaCl to a concentrationof 1:100

3)Centrifuge at 3,000 rpm for 30 min

4)0.1% formalin is added to the supernatant

5)Solution is inactivated at 32°C for 72 h

6) The vaccine can be preserved at 4-8°C for up to 14 months

DURING PREPARATION

1)0.2-0.5 ml vaccine (depending on the fish size)

2)Injected intraperitoneally or intramuscularly to each fingerling
3) At water temperature above 20°C