May 26, 2023 USTFA

Viral Hemorrhagic Septicemia Virus (VHSV) Detections Increasing in the Great Lakes

Courtesy of NAA:

The US Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Aquaculture Team suggests U.S. aquaculture producers, wild fish collectors, and all fish hatcheries to review and implement VHS precautions.  Already this year, USDA has received multiple reports of VHS (type 4b) detections in wild fish sourced from the Great Lakes.  It has been several years since USDA has received so many reports of VHS detections in such a short period.  At this time, it is unknown what this early trend may mean but the microbiological world tends to be cyclical.

The early detections have been found at different laboratories and, to date, fish have been clinically healthy (showing no signs of disease).  Viral Hemorrhagic Septicemia virus (VHSV) is a listed pathogen by the World Organisation for Animal Health (WOAH) as well as the National List of Reportable Animal Pathogens (NLRAD) as such detections, in wild and farm-raised fish, should be reported to state animal health officials and APHIS.

VHS is spread through infected animals and contaminated water.   If sourcing animals from the Great Lakes follow state requirements for health testing/permitting and keep lots of animals in an isolated area to avoid exposure to others. Clean and disinfect all equipment (e.g., trucks, nets, vessels, buckets, etc.) after every use or exposure to water or animals from the Great Lakes and do not move fishing equipment between water bodies without cleaning and disinfection. VHS is not zoonotic (i.e., contagious to humans).

If you have additional questions please contact Dr. Kathleen Hartman, Senior Staff Veterinarian -Aquaculture Health, USDA APHIS VS at or Dr. Nancy Hannaway, ASEP Assistant Director at

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