TPO and lymphopenia: Anemia and lymphopenia observed in infected fish at 11°C could be associated with the increased abundance of msa transcripts because this virulence factor shows several properties including the ability to bind salmonid erythrocytes (42), hemagglutinate mammalian erythrocytes (37, 39) agglutinate the leucocytes of various salmonid species (43), and adhere to Chinook salmon leucocytes (41).