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A deadly "zombie" disease that spreads rapidly in the United States and Canada in deer, elk and moose can pose a risk to humans if they eat sick venison.
Chronic wasting disease forces elk and deer to stop eating and behaving in a confusing way, their brains being transformed into sponges by abnormal proteins.
The slow-incubating disease, which leaves microscopic holes in the brain of an animal, is caused by prions.
It is the same dishonest proteins that caused bovine spongiform encephalopathy, or mad cow disease, in Britain in the 1980s.
About 200 people in Britain and Europe died of prion-based Creutzfeldt-Jakob disease about 10 years after consuming infected beef.
Today, about one in 2,000 people in Britain have inactive prions in their bodies, but have not yet presented symptoms, scientists said.
Until now, there is no evidence that chronic debilitating disease can affect deer species to humans.
But abnormal prion diseases can take years to manifest themselves and prions are known to turn into new forms, suggests a new opinion piece calling for action.
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A deadly "zombie" disease that spreads rapidly in the United States and Canada in deer, elk and moose can pose a risk to humans if they eat sick venison.
Until now, there is no evidence that chronic debilitating disease can affect deer species to humans. But abnormal prion diseases can take years to develop, and prions are known to transform into new forms. Pictured: The spread of the disease in the United States
Michael Osterholm, a specialist in infectious diseases at the University of Minnesota, and other scientists specializing in prion diseases believe that the disease causing chronic wasting could end up following a path similar to that of the mad cow disease and reach the man.
The doctors presented their arguments in "Chronic debilitating disease in deer: consequences for the transmission of prions to humans and other animal species" published in July.
"It is likely that human cases associated with the consumption of contaminated meat will be documented in the coming years," said Dr. Osterholm of the Center for Infectious Disease Research and Policy in the Minnesota Parliament in February.
"It is possible that a number of human cases are substantial and do not constitute isolated events," he told UPI.
"We have a historical perspective of mad cow disease, where the incubation period is probably 10 years or so."
After an outbreak of chronic debilitating disease in deer populations, Dr. Osterholm and other prion scientists call for a national campaign to test all deer carcasses in areas affected by the disease and discourage hunters and others to eat infected meat.
Between 7,000 and 15,000 animals infected with the disease are consumed each year by humans, according to the Alliance for Public Wildlife, according to the authors of the opinion paper on microbiology.
Chronic debilitating disease was detected for the first time in 1967 in a captive deer at a research facility at Colorado State University in Fort Collins.
The disease quickly spread to other deer in captivity, then to wild animal populations belonging to the deer family – deer, mullet and white tail, elk and moose.
Chronic wasting disease forces elk and deer to stop eating and behaving in a confusing way, their brains being transformed into sponges by abnormal proteins. In the photo: cattle are burned at the Lean quarry near Liskeard, Cornwall, in 1988 as part of the slaughter policy aimed at curbing BSE.
Since 2000, chronic wasting has spread in 26 states and Canadian provinces, with the highest concentration of cases in the United States in Colorado and Wyoming and on the border between Wisconsin and Illinois.
The disease has also spread to South Korea through the importation of captive elk and reindeer in Norway, Finland and Sweden.
Symptoms of the disease in animals include emaciation, heckling, drooling, falling ears and head, as well as lack of fear of humans.
Mutant prions are thought to spread through saliva, but may also be transmitted through urine or feces.
They also spread when hunters dress an infected animal on the ground and leave the guts behind.
Deformed prions have been found in dust and on plants and can last for years. They can not be destroyed by high temperature cooking or disinfectant treatment.
"Dizzy, confused, thin, with a vacant, vacant look" is the description Wendy White describes of elk deer staring intently at her windows, barely moving for days near her home at the foot of Colorado.
He climbed onto his deck, "seemed to look at me through the windows, asking me to do something with his glazed eyes."
A ranger of Colorado's parks and wildlife came in and fired at the animal, which was tested positive for the disease.
According to wildlife experts, herds in northern Colorado and Wisconsin currently account for 40-50% of infected animals.
Scientists say that hunters often shoot healthy-looking deer that may be in the early stages of the disease.
Public agencies of natural resources monitor the disease unevenly and many do not offer screening for chronic debilitating disease.
For States proposing to search for the disease, the results may take weeks, during which time a hunter may have eaten meat or taken a carcass for processing or taxing.
The World Health Organization, the Centers for Disease Control and Prevention and Health Canada advise against eating venison for animals with chronic melanoma.
The new opinion paper advocates the development of a "field test" for prions, able to immediately determine if the disease is present.
More sensitive testing technology and extensive testing could indicate further spread of the disease and lead to more animals slaughtered, said Mark Zabel, co-author of the opinion document and director. Associate of the Prion Research Center at Colorado State University.
The US hunting sector could be economically affected, but "deer populations would collapse because of the disease," said Dr. Zabel.
"If we do not anticipate that, there will be no hunting industry."
The slow-incubating disease, which leaves microscopic holes in the brain of an animal, is caused by prions
The opinion document also indicates that venison processing facilities that turn deer carcasses into sausages and that steaks may spread the disease.
Prions can contaminate the cutting and processing equipment of steel. Human prion diseases have already been spread through contaminated surgical instruments.
While mad cow disease prions were primarily present in the brain and spinal cord of cattle, prions of chronic debilitating disease appear in the infected lymph nodes and animal muscles belonging to the family of mammals. deer, said Dr. Osterholm.
Treatment plants could introduce diseases causing chronic dieback in the food chain, with disastrous results.
Some specialty meat companies, such as Silver Creek Specialty Meats in Oshkosh, Wisconsin, have completely stopped processing venison.
"Consumer safety is our number one concern and, however minimal the risk (if any) of human infection by this disease, we are not and will never want to put profit before safety and the good -being our customers, "said the company posted on its website.
Since National Wildlife Agencies have different methods for treating and recording diseases causing chronic wasting, the United States Geological Survey monitors incidents since the 2000s in North America with an updated map illustrating the occurrence of chronic wasting diseases. imprint of the disease.
"Human exposure definitely increases over time, with increasing prevalence in herds where MDC is established for the longest time.
Humans continue to harvest and consume these animals, "said Bryan Richards, Emerging Disease Coordinator at the National Wildlife Health Center in Madison, Wisconsin.
"The risk is that, when these prions are passed in series from one deer to another – after several generations, they might be more likely to switch to a human form of the disease," he said. he declares.
"Science suggests that risk is not static and can change over time."
In humans, prion diseases cause dementia, difficulty walking, hallucinations, confusion, fatigue, and speech difficulties.
Creutzfeldt-Jakob disease is not cured and is often diagnosed after death through pathological tests.
The mad cow disease in Britain was attributed to farmers in the mid-1980s who fed their cattle-infected protein from offal from other animals.
Scrapie, another malignant prion disease, has been infecting the brains of sheep and goats for hundreds of years without spreading to humans.
Because farmers and scientists of the time believed that mad cow disease could not touch humans, about 750,000 cattle infected with BSE have entered the food supply said the new article.
The delay in eradicating these infected cattle puts the population at risk, the scientists said.
Some American hunters still choose to take the risk and eat meat from animals with chronic wasting disease.
The Wisconsin Health Services Department has a list of 1,000 Wisconsin residents who have consumed meat from animals that test positive and have agreed to participate in a surveillance program long-term disease, said study coordinators.
Although the chronic debilitating disease does not spread to humans or livestock, it is still an epidemic of wildlife, said Dr. Osterholm.
Hunters are absolutely necessary to keep the problem at bay, he said.
In the United States, hunters killed about 5.6 million white-tailed deer in 2017, according to the Quality Deer Management Association.
"Hunters are a valuable part of herd management because they reduce the number of animal contacts that can spread chronic wasting disease," said Dr. Osterholm.
"We have every reason to support hunting, we just want to make sure that slaughtered animals can be eaten safely."
The complete results were published in the journal of the American Society of Microbiology.
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