Viral Hemorrhagic Septicemia
Gizzard Shad die off. Photo courtesy of Andy Noyes, NYDEC
- Viral hemorrhagic septicemia (VHS) is a severe disease of freshwater and marine fish.
- It can affect a number of recreational and sport fish species, such as muskellunge, small mouth bass, and yellow perch as well as a number of baitfish and commercial fish.
- There are four genetically different types of VHS. Genotypes I, II, and III are mainly found in Europe and Asia and cause severe disease in rainbow trout. Genotype IV (called the North American strain) has been found in wild fish along the East and West coasts of North America (IVa), and more recently in the Great Lakes watershed (IVb).
- The IVb strain was first identified in Lake Ontario in 2005. This was the first report of VHS in freshwater in North America. A number of new species of fish have been found to be affected.
- As of December 2008, VHS has been reported in dead or diseased wild fish in Lake Erie, Lake Ontario, Lake Huron, and Lake Michigan, the St. Lawrence River, and a number of inland lakes (in Michigan, New York, Wisconsin and Ohio).
- To date, VHS has not been found in aquaculture facilities in the Great Lakes region.
- VHS does not affect humans.
Signs of Disease »