Investigation of betanovirus infections in fish and the need to control them: a review

Betanodavirus is a very dangerous and acute infection in various species of fish, especially fish with economic value. The causative agent of this disease is from the Nodaviridae family. According to the conducted studies, more than 40 species of fish have been reported to be infected with viral neuronecrosis. Aquaculturists and fisheries experts believe that the disease caused by Betanovirus infection affects mostly marine fish, and in addition, it affects mostly larvae or young fish. Symptoms of betanodavirus include exophthalmia, anorexia, swelling of the swim bladder and whirling swimming of fish. However, many researchers stated that the central nervous system of fish is severely affected by beta-novirus infection, and the key symptoms of this viral infection are vacuolation of the spinal cord and brain. Viral neuronecrosis often spreads through horizontal transmission, but vertical transmission is also possible. So far, many efforts have been made by biologists and veterinarians around the world in order to control betanodavirus diseases. This research has shown that the implementation of health measures along with vaccination is a useful way to control betanodavirus disease in aquaculture industry. According to the findings of this study, the discovery of new vaccines with special potentials along with increasing the strength of the immune system of fishes using bioactive compounds including medicinal plants are acceptable ways to control betanodavirus disease in Iran's aquaculture industry.