Disinfection treatment halts VHS

[Legacy]

A disinfection solution currently used for salmon eggs also prevents transmission of the virus that causes viral hemorrhagic septicemia (VHS) in other hatchery-reared fish eggs, according to new US Geological Survey (USGS)-led research.

One of the most dangerous viral diseases of fish, VHS has caused large mortalities in wild fish stocks in the US and especially in the Great Lakes region, where thousands of fish have died from the virus over the last few years. The disease causes internal bleeding in fish yet is not harmful to humans.

The virus has thus far been detected in over 25 species of fish in Lakes Michigan, Huron, Erie, St Clair, Superior and Ontario, as well as the Saint Lawrence River and inland lakes in New York, Michigan and Wisconsin states.

Effective disinfection methods are crucial to natural resource agencies that collect eggs from wild fish stocks and private aquaculture because the spread of the virus to a fish hatchery could be devastating, said Mark Gaikowski, a USGS researcher who led the USGS and US Fish and Wildlife Service (USFWS) research team.

“If VHS virus is introduced into the aquaculture industry, it could lead to trade restrictions, as well as direct economic losses from the disease,†he observed.

USGS and USFWS researchers tested the effectiveness of using iodophor disinfection in walleye and northern pike eggs and found that it eliminated the active virus from fertilized eggs. Iodophor disinfectant solutions contain iodine formulated for use on fish eggs.

The researchers also found that, although some disinfection treatments reduced hatch, iodophor treatment at 90 minutes after fertilization occurred did not alter egg hatch or fry development.

Experts worry the virus could spread from the Great Lakes into new populations of native fish in the 31 states of the Mississippi River basin. Regulatory agencies in the US and Canada have already placed restrictions on the movement of fish or fish products that could pose a risk for the spread of VHS to regions beyond the known geographic range.

The research was funded by the USGS and the North Central Regional Aquaculture Centre (NCRAC) from the US Department of Agriculture Cooperative State, Research, Education and Extension Service. The iodine used during egg disinfection was donated by Western Chemical Inc, Ferndale, Washington.

Heres some good info: http://pubs.usgs.gov/fs/2009/3107/pdf/fs20093107.pdf

[Priority1]

Rob, Thanks for posting this.