Infectious Pancreatic Necrosis: Clinical and Immune Response of Adult Trouts to Inoculation with Live Virus

Abstract

Mature feral rainbow trout were inoculated with infectious pancreatic necrosis (IPN) virus and held at 12.5 C for 3 months to produce antibody and to determine whether or not disease would occur. Disease was not observed, but IPN virus-neutralizing antibody was found in pre-inoculation serum indicating the likelihood of prior infection. As measured by Neutralization Index, the immune response varied from weak to very strong. Neutralizing antibody was not found in sera from mature specific pathogen-free rainbow and brook trout. Although IPN virus also failed to produce clinical disease in adult brook trout it did establish a transient asymptomatic infection, and this resulted in high levels of neutralizing antibody.