Channel catfish virus

Alloherpesviridae
Virus classification
Group: Group I (dsDNA)
Order: Herpesvirales
Family: Alloherpesviridae
Genus: Ictalurivirus
Species

Channel catfish virus

Channel Catfish virus (Ictalurid herpesvirus 1) is a member of the Alloherpesviridae family that causes disease in catfish.[1] Infection with Channel catfish viral disease (CCVD) can cause significant economic loss in channel catfish farms.

Virology

The disease is endemic in the USA and there are reports of the virus in Honduras and Russia. Transmission is both horizontal and vertical. Channel catfish and blue catfish are the only fish that are susceptible to CCVD. Reservoirs of disease are clinically affected fish and recovered covert carriers.[2]

Disease occurs in fish less than a year old that weigh less than 10 grams. The critical environmental factor is water temperature with the disease occurring during warm weather. Outbreaks are normally seen only in farmed fish.

Clinical signs

Affected fish have pot-bellied appearance, haemorrhages on the fins and musculature and exopthalmos. Affected fish seem off balance and tend to swim erratically or close to the surface, eventually sinking to the bottom.

Fish that survive the infection have lifelong protective immunity but remain latent carriers of CCV. This is a significant source of disease for vulnerable fish.

Increased mortality in young catfish during warm weather, especially after stress is suggestive of CCVD.

Diagnosis

CCV can be detected in water containing infected fish and organs of diseased fish by virus neutralisation, fluorescent antibody testing, ELISA or PCR. FAT and ELISA should be used for diagnosis of clinically infected fish while virus neutralisation or PCR should be used to detect carrier fish. Lesions are seen on the liver, kidney and many other internal organs both histologically and grossly on postmortem examination.[2]

Treatment and control

There is no available treatment. Stress and high stocking-densities should be avoided to reduce disease occurrence. Appropriate quarantine and hygiene measures should be employed to prevent spread of disease. The virus is sensitive to acidic pH, heat and UV light and is inactivated by pond mud and sea water.[2]

References

  1. ↑ Huang S, Hanson LA (March 1998). "Temporal gene regulation of the channel catfish virus (Ictalurid herpesvirus 1)". Journal of Virology 72 (3): 1910–7. PMC 109482. PMID 9499043.
  2. 1 2 3 Channel Catfish Virus, reviewed and published by Wikivet accessed 18/08/2011

See also

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