Aquareovirus interference mediated resistance to infectious hematopoietic necrosis virus.

This study investigated the stimulation of specific host defenses to IHNV that are created by prior exposure to an avirulent reovirus (chum salmon reovirus; CSV). Preexposure of rainbow trout to CSV for 1 h resulted in a relative percent survival that ranged from 68 to 100% when fish were challenged with IHNV over an 8 week period. The levels of serum neutralizing antibodies detected 28 d after the IHNV challenge were significantly lower among fish receiving prior exposures to CSV than among non-CSV-treated fish. The differences in the humoral response to IHNV in the CSV-treated fish suggested that other immune defense mechanisms may be involved.