The course and outcome of spring viremia of carp shows seasonality, specifically outbreaks develop as the water temperature increases in spring, peaking between April-June. Young carp are particularly susceptible, as are farmed individuals.
Verical transmission is of minor significance.
The virus enters via the gills, whereupon replication occurs. In contrast, the intestinal mucosa represents a minor portal of entry, as bile rapidly inactivates the virus. The immune response involves neutralizing antibodies, natural resistance to infection, and interferon synthesis.