Inhibition of gill and skin damage by infectious hematopoietic cell necrosis virus in rainbow trout (Oncorhynchus mykiss) by astragalus polysaccharides through promotion of inactivated vaccine efficacy

However, Infectious Hematopoietic Organ Necrosis Virus (IHNV) causes Infectious Hematopoietic Organ Necrosis (IHN) disease, which in severe cases may lead to 100% mortality in juvenile rainbow trout, and has become a problematic issue in the development of aquaculture.IHNV leads to degenerative necrosis of hematopoietic tissues, and the symptoms, including darkening of the skin color, protrusion of the eyes, pallor of the gills, and distension of the abdomen, pose the greatest threat in the juvenile stage of the fish.

Gills and skin are mucosal tissues of fish that are in direct contact with the aquatic environment and are key sites of invasion for a variety of pathogens. Here, we investigated the effect of Astragalus polysaccharide combined with inactivated IHNV vaccine (APS+V) on gill and skin immunity in rainbow trout. Histopathological results showed that APS+V significantly inhibited IHNV-induced skin and gill damage and apoptosis.