Time course tissue distribution of infectious salmon anaemia virus in experimentally infected Atlantic salmon Salmo salar

Atlantic salmon Salmo salar L, were injected intraperitoneally with infecti ous salmon anaemia virus (ISAV)-infective tissue homogenate to clarify the tissue distribution of ISAV in a time course study. Fish were sampled at 11 different intervals between 1 and 40 d post-infection (p.i.) and mid-kidne y, head kidney, Liver, spleen, intestine, gills, muscle and heart were test ed for the presence of ISAV by reverse transcriptase polymerase chain react ion (RT-PCR). The results showed that during a disease outbreak, ISAV is pr esent in most organs. It was possible to detect ISAV at all sampling times in at least 1 of the fish examined. However, for the first 8 d p.i. positiv e RT-PCR results were predominantly found in samples from the head kidney a nd mid-kidney. Fish giving positive samples after Day 13 p.i. were RT-PCR p ositive in most organs. These results indicated that between Days 8 to 13 p .i. considerable replication of the virus occurred, combined with wide tiss ue dissemination.