Diagnosis
- Infection is often lethal due to the impairment of osmotic balance, and occurs within a clinical context of oedema and haemorrhages.
- Virus multiplication in endothelial cells of blood capillaries, haematopoietic tissues and nephron cells, underlies the clinical signs.
- The screening procedure for IHN is based on virus isolation in cell culture.
Disease Prevention And Management
- Good overall fish health condition seems to decrease the susceptibility to overt IHN, while handling and other types of stress frequently cause subclinical infections to become overt.
- Control methods for IHN currently rely on avoidance of exposure to the virus through the implementation of strict control policies and sound hygiene practices
- The thorough disinfection of fertilized eggs and the incubation of eggs and rearing of fry and alevins on virus-free water supplies in premises completely separated from those harbouring possible virus carriers and free from possible contact with fomites, are critical for preventing the occurrence of IHNV in a defined fish production site.
Treatment
References
Arnzen J.M., Ristow S.S., Hesson C.P. & Lientz J. (1991). Rapid fluorescent antibody tests for infectious hematopoietic necrosis virus (IHNV) utilizing monoclonal antibodies to the nucleoprotein and glycoprotein. J. Aquat. Anim. Health, 3, 109-113.
Deering R.E., Arakawa C.K., Oshima K.H., O'Hara P.J., Landolt M.L. & Winton J.R. (1991). Development of a biotinylated DNA probe for detection and identification of infectious hematopoietic necrosis virus. Dis. Aquat. Org., 11, 57-65.
Jorgensen P.E.V., Olesen N.J., Lorenzen N., Winton J.R. & Ristow S.S. (1991). Infectious hematopoietic necrosis (IHN) and viral hemorrhagic septicemia (VHS): detection of trout antibodies to the causative viruses by means of plaque neutralization, immunofluorescence, and enzyme-linked immunosorbent assay. J. Aquat. Anim. Health, 3, 100-108.
