I think one thing that could potentially help that's been happening for the last couple of years, in part from the department's work on PRV, is getting the hatcheries to make sure that they're disinfecting their eggs as much as they can to remove the potential for viral transmission, vertical transmission, from the females to the progeny. That certainly could decrease the level of the virus.
One reason that a hatchery might carry a virus more than wild fish is just the high density environment, so it's easy to spread. We don't really know a lot about vertical transmission of this particular virus, but it is possible that vertical transmission is a major source of transmission, and that, if they were to treat the eggs well, they could reduce the incidence of the virus in the hatcheries.