PATHOGENESIS OF VIRAL HEMORRHAGIC SEPTICEMIA VIRUS - CELLULAR ASPECTS

Leucocyte populations from rainbow trout subjected to experimental vir al haemorrhagic septicaemia virus (VHSV) infections under in vivo and in vitro conditions were analysed by flow cytometry. Quantitative anal ysis shows that only a low percentage of the leucocytes support viral replication. Lymphocytes, compared with monocytes granulocytes and mac rophages, are the least susceptible sub-population. A decrease in the amount of the phagocytic activity was observed after the cells were in fected with VHSV. Obvious modifications were observed through dot plot profiles in the composition of the cell sub-populations and in the ce ll morphology. In addition to a direct effect of VHSV on the macrophag es, a systemic effect is produced. This could also be related to the s tress induced by the experimental infection process.