Origins of mad cow disease

Posted on January 17, 2020 by Douglas Powell

Aristos Georgiou of News Week reports an international team of scientists has said that they may have identified the origin of mad cow disease. Known as bovine spongiform encephalopathy, the neurodegenerative disease destroys the brain and spinal cord in cattle, causing death.

Since BSE first appeared in the 1980s in the United Kingdom, scientists have tried to identify how the disease emerged, however, no one hypothesis has been confirmed.

For a study published in the journal Proceedings of the National Academy of Sciences, the team of scientists investigated the origins of BSE by injecting a particular variant of scrapie disease into mice which have been genetically modified with bovine DNA.

The researchers say that, unexpectedly, the injection of the scrapie strain into the genetically modified mice resulted in the propagation of classical mad cow disease prions. These prions are present in natural form in the scrapie variant.

This observation indicates that the illness could be transmitted between different species and that the modified mice could develop mad cow disease, according to the study.

Olivier Andreoletti, an author of the paper from the French National Institute for Agronomic Research (INRA,) told AFP that the modified mice are “a very good model, which works well in terms of knowing what would happen if one exposed cows to those prions.”

He noted that the results provide, for the first time, and “experimentally underpinned explanation” for the appearance of mad cow disease in the U.K. in the 1980s.

After emerging, the disease spread in cattle across Europe, North America and other regions of the globe. This process was exacerbated by the fact that cows were being given feed which contained tissue from other cows infected with the disease.

More Brits could still die from human form of mad cow disease

Posted on July 5, 2019 by Douglas Powell

More Brits could be affected by mad cow disease as experts warn many could be infected without knowing. A second wave of deaths related to eating beef contaminated with Bovine Spongiform Encephalopathy (BSE) – or mad cow disease – could sweep the UK.

In 1993 Britain’s worst food scandal saw 4.4 million cows culled and claiming the lives of 177 people who had developed the human form of it, called Creutzfeldt-Jakob disease (vCJD). Since then, strict controls have been in place to prevent BSE contaminating food products and the use of meat and bone mix is illegal. But humans could be affected for up to 50 years, warn experts. Neurology professor, Richard Knight, of Edinburgh’s CJD Surveillance Unit, told a BBC investigation – airing July 11 – that it is still unclear how many could be affected. He said: ‘There is still so much uncertainty about this disease.

‘And one of the things that is uncertain is how many people in the UK are silently infected. ‘At the moment I have to say we are simply not sure, but every prediction suggests there are going to be further cases.’ vCJD is caused by prions, which are infectious agents made up mainly of proteins. A study of a similar disease in 2009, caused by prions, showed the disease may incubate undetected for much longer. All affected had carried the same MM genetic makeup, but in 2009 victim Grant Goodwin, 30, became the first person to die of vCJD, despite carrying the different gene type of MV. In 2014, a British man, 36, became the second MV carrier to die from the disease.

CJD sucks: UK special forces legend who blew up Saddam’s communications network dies of CJD

Posted on August 29, 2017 by Douglas Powell

A superfit, special forces legend from Gloucestershire who carried out a real-life “mission impossible” behind enemy lines has died after developing the human form of Mad Cow Disease.

Father-of-three Mark Phillips MBE was just 56 when he died earlier on August 12 and was well-know figure in military circles for his brave exploits in Afghanistan and Iraq.

Known as Lt. Colonel Mark ‘Foggy’ Phillips of the Special Boat Squadron, he is said to have being diagnosed with Sporadic-Creutzfeldt-Jakob Disease in June. It is so rare that only one in one million people develop it.

It is believed that Mr Phillips attended Balcarras School in Cheltenham before embarking on an outstanding military career which saw him join the SBS in 1987 and become one of its fittest and most respected officers.

Commandant General of the Royal Marines, Major General Rob Magowan, led the tributes to the officer who is said to have carried out hundreds of forays behind enemy lines, including an audacious mission to blow up Saddam Hussein’s telecommunications cables buried under a sports arena near the centre of Baghdad.

Sources say diversion was created so Lt Col Phillips and his SBS team could fly in on Chinooks at low altitude to avoid the radar and then then plant hundreds of pounds of explosives.

An SBS source told the Daily Mail that many of those in the know did not expect them to make it back alive from the 1991 raid because it was the “It was the proverbial ‘mission impossible’.”

But it was so successful in bringing down Iraqi communications during the first Gulf War that a piece of cable recovered from the scene was later put on display at the Imperial War Museum.’

The military man returned to Iraq in 2003 with the SBS and in 2008 he was said to have joined a special UK-US Special Forces unit known as Task Force 42 which tracked Taliban commanders.

Major General Magowan said: “Foggy was an inspiration, both to me and across our Corps. Bright, physically strong, courageous, hugely visionary and immediately engaging, he had all the attributes of a Royal Marine.

“People were swept up by his energy and leadership. I first met him on an adjacent rowing machine and I must admit to feeling intimidated. As an organisation, we are considerably less rich with his passing.”

Although he kept out the public eye, he was also known as an athlete and the 1990s he won the 125-mile Devizes to Westminster canoe race, which has previously won by Paddy Ashdown and Ranolph Fiennes, four times in succession.

Organisers paid tribute to him on the event’s Facebook page and said: “His athletic feats are legend and amongst these achievements, he was a 4 times winner of the Devizes to Westminster canoe race.

“Lt Col Mark Phillips MBE, Royal Marines was a professional of the highest order – we will be hard put to meet his like again.”

According to his LinkedIn profile he left the military in 2013 and had his own security business.

A death notice in GloucestershireLive read: PHILLIPS M.B.E. Mark Sadly passed away on 12th August 2017 after a short illness. “Husband to Jacqui and father to Emily, George and Bethany. Son of Brian and Pat and brother to Stephen and Adrian. Funeral service will take place at Milton Abbey, Dorset on 25 August.”

Atypical BSE in Alabama cow

Posted on July 19, 2017 by Douglas Powell

The U.S. Department of Agriculture (USDA) announced an atypical case of Bovine Spongiform Encephalopathy (BSE), a neurologic disease of cattle, in an eleven-year old cow in Alabama. This animal never entered slaughter channels and at no time presented a risk to the food supply, or to human health in the United States.

USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Laboratories (NVSL) have determined that this cow was positive for atypical (L-type) BSE. The animal was showing clinical signs and was found through routine surveillance at an Alabama livestock market.

BSE is the form that occurred primarily in the United Kingdom, beginning in the late 1980’s, and it has been linked to variant Creutzfeldt-Jakob disease (vCJD) in people. The primary source of infection for classical BSE is feed contaminated with the infectious prion agent, such as meat-and-bone meal containing protein derived from rendered infected cattle. Regulations from the Food and Drug Administration (FDA) have prohibited the inclusion of mammalian protein in feed for cattle and other ruminants since 1997 and have also prohibited high-risk tissue materials in all animal feed since 2009.

Atypical BSE is different, and it generally occurs in older cattle, usually 8 years of age or greater. It seems to arise rarely and spontaneously in all cattle populations.

This is the nation’s 5th detection of BSE. Of the four previous U.S. cases, the first was a case of classical BSE that was imported from Canada; the rest have been atypical (H- or L-type) BSE.

New blood tests can detect prions

Posted on December 24, 2016 by Douglas Powell

Tine Hesman Saey of Science News reports a new blood test can detect even tiny amounts of infectious proteins called prions, two new studies show.

Incurable prion diseases, such as mad cow disease (BSE) in cattle and variant Creutzfeldt-Jakob disease (vCJD) in people, result from a normal brain protein called PrP twisting into a disease-causing “prion” shape that kills nerve cells in the brain. As many as 30,000 people in the United Kingdom may be carriers of prions that cause vCJD, presumably picked up by eating BSE-tainted beef. Health officials worry infected people could unwittingly pass prions to others through blood transfusions. Four such cases have already been recorded. But until now, there has been no way to screen blood for the infectious proteins.

In the test, described December 21 in Science Translational Medicine, magnetic nanobeads coated with plasminogen — a protein that prions grab onto — trap prions. Washing the beads gets rid of the rest of the substances in the blood. Researchers then add normal PrP to the beads. If any prions are stuck to the beads, the infectious proteins will convert PrP to the prion form, which will also stick to the beads. After many rounds, the researchers could amplify the signal enough to detect vCJD prions in all the people in the studies known to have the disease.

No healthy people or people with other degenerative brain diseases (including Alzheimer’s and Parkinson’s) in either study had evidence of the infectious proteins in their blood. And only one of 83 people with a sporadic form of Creutzfeld-Jakob disease tested positive. Those results indicate that the test is specific to the vCJD prion form, so a different test is needed to detect the sporadic disease.

In two cases, researchers detected prions in frozen blood samples collected 31 months and 16 months before people developed vCJD symptoms.

Low incidence of TSEs in the EU, says EFSA

Posted on December 3, 2016 by Douglas Powell

EFSA has published its first EU summary report on the monitoring of Transmissible Spongiform Encephalopathies (TSEs) in cattle, sheep and goats. Previously, the annual reports on TSEs were compiled by the European Commission.

TSEs are a group of diseases that affect the brain and nervous system of humans and animals. With the exception of Classical BSE, there is no scientific evidence that other TSEs can be transmitted to humans.

A low number of BSE cases in cattle were detected in EU Member States, none of which entered the food chain.

Some of the main findings of the report are:

Five cases of BSE in cattle have been reported in the EU, out of about 1.4 million animals tested.

641 cases of scrapie in sheep (out of 319,638 tested) and 1,052 in goats have been reported (out of 135,857 tested) in the EU.

This report provides results on data collected by all EU Member States, Iceland, Norway and Switzerland for 2015 on the occurrence of bovine spongiform encephalopathy

Beneficial role clarified for brain protein associated with BSE

Posted on August 9, 2016 by Douglas Powell

Studying mice and zebrafish, researchers from Washington University School of Medicine in St. Louis and the University of Zurich have shown that the proteins — when properly folded — play a vital role in nerve cell function by maintaining the insulation around axons, the nervous system’s electrical “wiring.”

The study appears August 8 in the journal Nature.

Improperly formed prion proteins that cause disease are infectious because they hijack their neighbors, resulting in misfolded proteins and setting off a domino effect that spreads through the brain destroying tissue. Although the role of prion proteins in these fatal brain diseases is well-known, scientists have long puzzled over the normal function of the protein, called PrPC.

“Previous studies have suggested a role for prion proteins in maintaining neurons, but until now, no one knew how the properly folded versions of the proteins function,” said co-author Kelly R. Monk, PhD, an associate professor of developmental biology at Washington University. “It’s surprising to see that the protein has a role in maintaining the structure of nerve cells, considering that a misfolded version of PrPC is known to cause fatal brain diseases.”

Past work by the researchers at the University of Zurich demonstrated that mice lacking PrPC had disruptions in the insulation surrounding axons, but the reasons for the disruptions were unclear. The new study demonstrates that PrPC binds to Schwann cells, which are cells that provide support for the brain’s neurons. Schwann cells produce the nerve-insulating protein called myelin and then wrap this insulation around the long, thin axons. Properly insulated axons enable the rapid propagation of nerve signals. Specifically, PrPC binds to a docking site on Schwann cells called Gpr126.

In past work, Monk and her Washington University colleagues demonstrated that the docking site on cells played an important role in nerve formation during embryonic development in zebrafish and in mice. But the new study identifies roles for both Gpr126 and PrPC in maintaining the integrity of neurons through adulthood.

When either of these components is missing, Monk said mice experience a gradual loss of interactions between Schwann cells and axons, with a resulting loss of of myelin. Without this important insulation, walking progressively becomes more difficult for mice, and they eventually reach a state of paralysis.

“We have identified a definitive function for the normal prion protein and clarified how it works on a molecular level,” said senior author Adriano Aguzzi, MD, PhD, of the University of Zurich. “Our study answers a question that has been intensely researched since the prion gene’s discovery in 1985.”

The researchers said the findings may have implications for understanding and eventually treating nerve disorders that result from the loss of the insulating myelin sheaths, such as Charcot-Marie-Tooth disease and other devastating peripheral neuropathies.

‘Veal calves that regain the ability to walk after being warmed or rested may enter the food supply’ No more

Posted on July 14, 2016 by Douglas Powell

The U.S. Department of Agriculture’s (USDA) Food Safety and Inspection Service (FSIS) announced changes today to improve humane handling inspections at facilities that produce veal meat.

With this change, FSIS will begin to require that veal calves that are brought to slaughter but cannot rise and walk be promptly and humanely euthanized, and prohibited from entering the food supply. Previously, FSIS has allowed veal calves that are unable to rise from a recumbent position to be set aside and warmed or rested, and presented for slaughter if they regain the ability to walk. FSIS has found that this practice may contribute to the inhumane treatment of the veal calves. This change would improve compliance with the Humane Methods of Slaughter Act by encouraging improved treatment of veal calves, as well as improve inspection efficiency by allowing FSIS inspection program personnel to devote more time to activities related to food safety.

Additionally, after review and consideration of comments to the proposed rule, FSIS is amending the regulations by removing a provision that requires ante-mortem inspection to be conducted in pens. This final rule makes clear that FSIS inspectors have the authority to conduct ante-mortem inspection and condemn non-ambulatory disabled veal calves the moment they arrive on the premises of the establishment.

“FSIS is dedicated to ensuring that veal calves presented for slaughter at FSIS-inspected facilities are treated humanely,” said Deputy Under Secretary Al Almanza. “Prohibiting the slaughter of all non-ambulatory veal calves will continue this commitment and improve compliance with the Humane Methods of Slaughter Act.”

Since 2004, FSIS has prohibited the slaughter of non-ambulatory cattle for human food because the inability to rise may be a symptom of Bovine Spongiform Encephalopathy (BSE). While BSE is not a serious risk in cattle younger than 30 months of age, the regulations apply to all cattle, including veal calves. Currently, unlike adult cattle, veal calves that regain the ability to walk after being warmed or rested may enter the food supply. In 2013, FSIS granted a petition by the Humane Society of the United States asking the agency to remove this provision. This new rule will remove the provision, requiring that non-ambulatory calves be promptly and humanely euthanized, in keeping with requirements for adult cattle.

The final rule will be effective 60 days after publication in the Federal Register. A draft copy of the final rule is available here:http://www.fsis.usda.gov/wps/portal/fsis/topics/regulations/federal-register/interim-and-final-rules.

News amplification: Mad cow disease far greater impact on beef purchases than E. coli

Posted on May 18, 2016 by Douglas Powell

In December 2003, Bovine Spongiform Encephalopathy (BSE) was discovered in the United States. This food safety event received extensive media coverage and prompted changes in regulatory controls.

Using a panel selection model, we show that prior to December 2003, ground beef recalls had no impact on household purchases of ground beef, even for households that were located in the recall-defined geographic areas. However, we find robust evidence that the 2003 BSE event caused a change in the way people view and respond to recalls of ground beef, a change that persisted for at least two years following the BSE event.

The average impact of a ground beef recall in the post-BSE period is a 0.26 lb per person reduction in retail purchases of ground beef. A decline in purchases of this magnitude would result in over $97 million in losses to the beef industry in a two-week period following a nationwide recall.

This dwarfs the economic impacts of directly removing recalled beef from supply chains and provides FSIS increased regulatory power due to higher overall industry costs associated with food safety violations.

Changes in U.S. consumer response to food safety recalls in shadow of a BSE scare

Mykel Taylora, H. Allen Klaiberb, Fred Kuchlerc

Food Policy, Volume 62, July 2016, Pages 56-64, doi:10.1016/j.foodpol.2016.04.005

http://www.sciencedirect.com/science/article/pii/S0306919216300239

Why is contaminated feed still circulating, 15 years later? CFIA says small amount of feed likely cause of Alberta mad cow disease

Posted on December 2, 2015 by Douglas Powell

Canada’s food safety watchdog says a small amount of leftover contaminated feed was the most plausible cause of mad cow disease discovered last February on a farm near Edmonton.

The Canadian Food Inspection Agency released a report Monday that says no part of the Black Angus beef cow entered the human food or animal feed systems.

The report says no significant events could be linked to the discovery of bovine spongiform encephalopathy (BSE) near Edmonton and no other sick animals were found.

The February case — the 19th in Canada — prompted a few countries to place temporary restrictions on Canadian beef imports.

An investigation report says the cow was born at a nearby farm almost two years after Canada brought in more strict controls on animal feed to prevent BSE. A previous case was diagnosed on the same birth farm in an animal born in 2004.

“No significant events could be linked with this case but the potential for the carry-over of a small amount of residual contaminated feed could not be discounted,” says the report.

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