Epizootic epitheliotropic disease virus (EEDV, Family Alloherpesviridae) emerged in the 1980’s as a significant mortality source in hatchery-reared lake trout (LT; Salvelinus namaycush) in the Great Lakes basin and continues to impede hatchery-based LT conservation and rehabilitation efforts today. Little is known about EEDV disease ecology, a matter hampering EED prevention/control. To address unknowns surrounding EEDV host range, transmission, and susceptibility to hatchery disinfectants, three studies were conducted. In the first, I clarified the EEDV host range, whereby the virus was detected in LT, splake (LT x brook trout, Salvelinus fontinalis), and mottled sculpin (Cottus bairdii), but not the other 8 experimentally challenged fish species. Susceptibility to EEDV varied within two LT strains (e.g., Lake Superior and Seneca strains), but the virus was able to replicate to high titers in both, as well as rarely in splake. In contrast, there was no evidence for virus replication in mottled sculpin. In study 2, I examined virus shedding in microchipped and EEDV challenged LT, which showed that shedding into water began at 9 days post-infection (pi), was greatest ~three weeks pi (i.e., <108 virus copies/fish/hour), and continued for at least 9 weeks pi. In study 3, I found Virkon® Aquatic to be effective at preventing EEDV contagion on hatchery tools at the manufacturer recommended concentration/duration. Collectively, findings provide fishery managers with valuable knowledge on the biological properties of EEDV so that improved strategies can be devised to prevent and control EEDV in Great Lakes hatcheries and beyond.
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