Eating Farmed Fish Could Transmit Infectious Prions From Cows With BSE To Humans
OK, everyone from your mother to your cardiologist says you should be eating more fish. The American Heart Association recommends eating at least two servings of fish per week.
But if you do not live on the coast or some faraway island, getting fresh fish that only a short time earlier was swimming freely sea is not easy. Chances are that Salmon or Halibut you buy in Des Moines or Atlanta in the winter is “farmed fish,” raised in a pen and just maybe fed prions from cows with bovine spongiform encephalopathy (BSE).
Farmed fish could be a source of transmission of BSE to humans, risking variant Creutzfeldt Jakob Disease (vCJD), the human form of Mad Cow Disease.
This is the possibility is raised in the June issue of the prestigious Journal of Alzheimer's Disease. The authors, Dr. Robert P. Friedland, Dr. Robert B. Petersen, and Dr. Richard Rubenstein hail, respectively, from the medical schools at Louisville, Case Western, and the State University of New York.
“We are concerned that consumption of farmed fish may provide a means of transmission of infectious prions from cows with bovine spongiform encephalopathy to humans, causing variant Creutzfeldt Jakob disease, “ the doctors write.
“We have not proven that it’s possible for fish to transmit the disease to humans. Still, we believe that out of reasonable caution for public health, the practice of feeding rendered cows to fish should be prohibited,” Friedland said. “Fish do very well in the seas without eating cows,” he added.
Creutzfeldt Jakob disease is an untreatable, universally fatal disease that can be contracted by eating parts of an animal infected with bovine spongiform encephalopathy (BSE or mad cow disease).
An outbreak in England attributed to infected beef prompted most countries to outlaw feeding rendered cow material to other cattle because the disease is so easily spread within the same species. The risk of transmission of BSE to humans who eat farmed fish would appear to be low because of perceived barriers between species. But, according to the authors, it is possible for a disease to be spread by eating a carrier that is not infected itself. It’s also possible that eating diseased cow parts could cause fish to experience a pathological change that allows the infection to be passed between the two species.
“The fact that no cases of Creutzfeldt Jakob disease have been linked to eating farmed fish does not assure that feeding rendered cow parts to fish is safe. The incubation period of these diseases may last for decades, which makes the association between feeding practices and infection difficult. Enhanced safeguards need to be put in place to protect the public,” Friedland said.
Deaths from Creutzfeldt Jakob disease in the United Kingdom attributed to eating infected beef total 163. Bovine spongiform encephalopathy has been identified in nine Canadian and three U.S. cattle.
