In vitro studies of infectious pancreatic necrosis virus infections in leucocytes isolated from Atlantic salmon ( Salmo salar L.)

Leucocytes were isolated from blood and head kidney of Atlantic salmon carrying infectious pancreatic necrosis virus (IPNV). Results that indicated an IPNV replication were only obtained from adherent head kidney leucocytes (mainly macrophages). IPNV specific fluorescence was detected in both carrier and in vitro infected macrophages, and the number of fluorescent cells increased during a week in culture. However, the release of infectious IPNV was low. Preliminary results also indicated that in vitro IPNV infections of macrophages seemed to reduce the respiratory burst activity in these cells.