Infectious Salmon Anemia Virus

Also known as: ISAV

Infectious Salmon Anemia Virus (ISAV) is a highly contagious marine orthomyxovirus that primarily affects Atlantic salmon (Salmo salar). The virus is transmitted horizontally, often through seawater or contaminated equipment, and was first identified in Norway. It has since spread globally, largely through movement of infected fish stock. Infected fish may display behavioral changes such as lethargy, loss of appetite, abnormal swimming, and gasping at the surface. Externally, pale gills, hemorrhaging along the abdomen and flanks, and swollen abdomens are common. Internally, ISAV infection causes anemia, pale organs, and pinpoint hemorrhages in adipose tissues. Diagnosis is confirmed through histological observations and molecular techniques like PCR. While ISAV has no known effects on human health, it can cause significant losses in aquaculture. Vaccines exist, but no therapeutic treatments are currently available.

Distribution: Global, typically problematic in farms of Atlantic salmon
Detection Methods: PCR (unspecified)
Hosts: Atlantic salmon; Pacific salmon and trout may act as carriers
Target Tissue: Gills, heart, kidney, liver, spleen