The virus was identified in dead largemouth bass collected by the Wisconsin Department of Natural Resources (DNR) during an investigation into a May 2015 fish kill in Pine Lake.
Scientists at the U.S. Fish and Wildlife Service’s La Crosse Fish Health Center isolated the previously unknown virus, sending it to a “virus-hunting laboratory” operated by Tony Goldberg in the Department of Pathobiological Sciences at the University of Wisconsin-Madison’s School of Veterinary Medicine, reports Science News Line.
There, the virus’ genome was broken down using “next generation sequencing” technologies and the hunt began. Goldberg and his colleagues scoured the genetic databases, looking to see if the virus was known or something unique and new. Goldberg says the virus is indeed, new to science. It has been dubbed largemouth bass reovirus (LMBRV).
Although the virus has yet to be directly linked to the fish kill in Pine lake, Goldberg says the virus is a distant relative of viruses associated with disease in other fish species. This makes LMBRV a prime suspect in the May 2015 largemouth bass fish kill, reports local NBC affiliate WMTV15.
According to The Fish Site, Goldberg says, “We can’t say if it is directly responsible for fish mortality yet. But these kinds of viruses are known pathogens of fish, so we would be prudent to be concerned about it.”
Goldberg, an epidemiologist, world expert on emerging infectious disease and associate director of research at the UW-Madison Global Health Institute points out this latest find comes against the backdrop of another deadly fish pathogen, viral hemorrhagic septicemia virus, which was found in 2006 in Lake Winnebago.
Viral hemorrhagic septicemia virus has since spread, and been found in lakes Michigan and Superior. Should it continue to spread, it would pose a threat to Wisconsin’s inland fisheries, affecting a number of fish species, including musky, pike, bass, panfish and trout.
“Largemouth bass reovirus is only the second representative of its group of viruses,” says Goldberg. “This family of viruses are emerging pathogens that infect all sorts of animals. They cause kills in marine and freshwater fisheries, including in wild and farmed populations.”
The findings of the investigation were reported in the Journal of General Virology on August 1, 2016, with the title: “Novel reovirus associated with epidemic mortality in wild Largemouth Bass (Micropterus salmoides).”
