Figure 1.

Drivers of emerging infectious diseases in aquaculture. (A) Virus drivers include mutations leading to virulent strains and the ability to infect different host species. (B) Fish host drivers include susceptibility to infection due to low immunity. (C) Anthropogenic drivers include farming practices that include high stocking density and poor feeding regimes that cause fish to become stressed and increase susceptibility to infection. (D) Environmental drivers include adverse conditions such as changes in alkalinity, reduced dissolved oxygen, and increase in nitrites that predispose fish to viral infection.