Epidemiology of the spread of viral diseases under aquaculture

Aquaculture production is increasing rapidly worldwide. However, production has been associated with the emergence of several novel diseases, including viral diseases, that have caused serious problems for producers. Using examples largely from salmon farming in Scotland I review briefly the factors that allow transmission to occur in aquaculture. These include transmission through the water, which is relatively local to the infected farm, and anthropogenic transports (such as transport of fish between sites) that may occur over very long distances. A Disease Management Area (DMA) approach, as developed in Scotland to fight infectious salmon anaemia, can be effective at reducing pathogen transmission and hence disease emergence.

► Increased Aquacultural production is associated with emerging diseases.
► Transport with water currents can carry viruses between farms within an area.
► Anthropogenic transport can be over larger distances (even global).
► Area management may reduce risk of emergence of disease.