Prion Disease Threatens Livestock, Humans
Editor’s Note: A deadly prion is a deadly prion. Hiding behind ignorance and special interests is doing no one any good. Prion disease is always fatal. There is not a cure. Prions migrate, mutate and multiply. Sick animals (including livestock and people) that have prion disease contaminate their environment with prions that are discharged via blood, urine, feces, saliva, and milk. These prions enter the soil and are carried into groundwater, surface water, streams, rivers, ponds and lakes.
When people have prion disease, their bodily discharges contaminate entire sewer systems–forever. When biosolids and reclaimed sewage water are discharged from the sewage plant, that sludge is then applied to cropland across Wisconsin and the nation. In fact, few counties in Wisconsin have not been subjected to sewage disposal on cropland. Are prions in sewage sludge infecting the deer? If so, what’s to keep the prions from migrating and infecting Wisconsin’s multi-billion dollar dairy herd? The species barrier is a myth. Prion disease is prion disease and a deadly prion is a deadly prion. Don’t buy the spin about “no evidence of” or “species barrier will protect you.” That is pure BS to sell you a bill of goods that covers a lot of asses.
Furthermore, asking hunters to kill sick deer, dress it and process it without fear is reckless. As the following article illustrates, hunters are dressing and processing thousands of carcasses riddled with prions every year. In those cases, infected blood and tissue will permanently contaminate the hunter’s knives and saws and clothes and processing plants and beyond. If I dare cut through the spinal cord to remove the head for testing, my chances of prion exposure escalate. If the test comes back positive, I will throw out the remaining packs of deer burger. I should throw out my knife and burn my clothes. Unfortunately, those items have already been in my home and garage. Why isn’t the Fish & Game and Divisions of Wildlife giving hunters better safeguards? With mismanagement like this, eradicating deadly prion disease from deer herds and entire ecosystems is a pipe dream–or make that a nightmare. If you live in Wisconsin or any state impacted by chronic wasting disease, challenge them to hire me as a consultant on this life-and-death issue.
CWD A Lost Battle
The rate of chronic wasting disease (CWD) is on the rise among deer in Iowa County, Wisconsin and elsewhere across the state. CWD is a fatal, transmissible spongiform encephalopathy (TSE) similar to what is commonly known as mad cow disease that is caused by twisted proteins, or prions. For hunters, writes outdoors reporter Patrick Durkin, this means the disease might be affecting the herd now. For anyone who eats venison, this means greater chances that the disease could conceivably make the species jump and infect humans, according to Dave Clausen, a veterinarian whose term on Wisconsin’s Natural Resources Board expired in May.
About one out of every three male deer aged 2.5 years and older carries CWD in north-central Iowa County, as does one out of every six yearling male deer (1.5 years old), according to the Wisconsin State Journal, and the rates are climbing at about ten percent a year. As several experts told Durkin, the increasing rates are “unprecedented,” “frightening,” and “disturbing.”
Over 633,000 hunters purchased licenses to hunt white-tailed deer in Wisconsin in 2012, according to the Department of Natural Resources (DNR). The primary deer hunting season (for guns) runs for nine days in late November. An exact number of Wisconsinites who eat hunted venison is not known, although media reports indicate it is large. But testing of these deer for CWD is on the decline, even as infection rates rise. In 2002, over 40,000 deer were tested in Wisconsin, and .51 percent tested positive. In 2012, 6,611 deer were tested, and 5.13 percent tested positive.
As then-Natural Resources Board member Clausen wrote in a white paper on CWD and human health in 2012, the “ever-increasing number of CWD infected deer on the landscape . . . and the accompanying exponential increase of environmental contamination with CWD prion will result in increased inter-species, including human, exposure to the CWD prion. Under our current management strategy, human exposure will increase.”
People Eating Infected Venison
One of the reasons why it is possible for CWD to make the species jump to humans is because of insufficient warnings to hunters by the DNR, Clausen says. The DNR website says there is “no strong evidence” that CWD can be passed to humans, but warns hunters to “minimize contact with the brain, spinal cord, spleen and lymph nodes” when processing deer.
But in 2010, the World Health Organization (WHO) changed its definition of infective tissue to include skeletal muscles from CWD-infected deer and elk. And a 2012 Centers for Disease Control and Prevention (CDC) study notes, “CWD prions are present nearly ubiquitously throughout diseased hosts, including in muscle, fat, various glands and organs, antler velvet, and peripheral and CNS [central nervous system] tissue.” It concludes that the potential for human exposure to CWD from handling or eating material from infected deer “is substantial and increases with increased disease prevalence.” Both the WHO and the CDC recommend that people avoid eating meat from CWD-infected deer or elk.
Unlike the WHO and CDC, Clausen said the Wisconsin Department of Health and Safety (DHS) will not publicly recommend against eating infected venison until there is hard evidence that someone has gotten Creutzfeldt-Jakob Disease (CJD, the human TSE) from eating infected venison. But he believes that the government should be operating on the precautionary principle — that “if something is plausible, that we should be erring on the side of caution unless we have absolute hard evidence that it’s not possible.”
But, Clausen adds, the “precautionary principle is bad for business.” If people become so concerned about contracting CWD that they stop hunting, it means a potential decrease in DNR revenue; and the federal government has stopped funding CWD testing and research in the last year or two. UW-Madison Professor Michael Samuel has seen federal research funds for studying “disturbing” new trends in CWD dry up. “There’s little interest in CWD these days, Wisconsin and nationwide,” he told Durkin.
With testing on the decline, the DNR “has tracked hundreds of cases” in which people have eaten infected venison and “knows that there are many more,” according to the Wisconsin Center for Investigative Journalism. As the rates of the disease rise — as the CDC notes — “the potential for human exposure to CWD by handling and consumption of infectious cervid material increases.”