Surviving the COVID-19 pandemic is on our minds. With no antiviral agent to stop this coronavirus infection, the real hope is to survive long enough to receive one of the effective vaccines to generate antibodies to block infection. In addition, protective masking, hand washing, and social avoidance are necessary.
However, of grave concern, we have another untreatable always fatal disease spreading epidemically through wildlife around the world and locally. The disease is caused by structurally abnormal proteins and is called Chronic Wasting Disease (CWD) based on the appearance of the sick animals. Every infected animal dies.
No human is known to have been infected by eating meat from wild game animals infected with CWD, but based on prion science, it could happen.
My interest in prion disease spans decades and prompted me to write a novel about its spread. If it’s spread through zoo animals that consumed infected beef, will it jump species barriers and infect others?
In the UK, numerous exotic zoo ruminants and bison died after eating infected meat and bone meal. Prion disease also killed captive wild cats throughout Europe. In the outbreak of human prion disease in Great Britain, it also killed hundreds of pet cats. Outbreaks in farmed mink have also occurred. All infected animals develop severe behavior changes, restlessness, sometimes aggressiveness or timidity. Infected deer lose their fear of humans. They develop excessive salivation, tremors and staring. Their inability to eat results in muscle wasting and starvation, thus the CWD descriptive term.
In the 1990s, a protein prion form crossed the species barrier from cattle to humans killing hundreds of people who ate the infected beef.
When humans developed the disease from eating infected beef, the incubation period was often years and occurred in younger people. Symptoms ranged from early visual changes, progressing to memory loss, motor disturbances and balance problems, followed by advancing dementia, coma, and death. This human disease is called variant Creutzfeldt-Jakob Disease (vCJD). Variant correlates with the form of CJD from diseased beef.
Prions are unlike any other infections, not a viral or bacterial. Prions are highly stable structurally abnormal proteins that transmit the fatal disease through contamination and consumption. This means, if you eat beef from cattle with Mad Cow Disease, you may die. Cooking the meat well done does not inactivate prions. The structure is so stable in tissue it must be incinerated to kill it.
The abnormal proteins can survive on surfaces for long periods. The usual soap and water washing of knives, truck beds or counters where meat is butchered with is not adequate to decontaminate the areas. Research shows 40% Clorox can inactivate prions if soaked for five minutes.
Prion infected carcasses left in the field after removing consumable portions of a game animal contaminates the soil. Depending on soil type, prions may not decompose and could be infectious in the ground for years and can contaminate the watershed. Ideally, the infected game and carcasses should be burned.
Hunting is big business. When purchase of specialized clothing, weapons, vehicles and licensing fees are included, hunting enthusiasts spend billions each year. Devoted sportsmen are unlikely to give up eating game meat or stop hunting in spite of prion risks, but all hunters are encouraged to follow guidelines published by state hunting websites. All big game should be tested for prions before consuming.
Infected game animals appear normal for 1-2 years before showing symptoms, so eating a normal appearing animal without testing places you at risk. Testing tonsil or brain tissue reveals the abnormal structures, but the abnormal prions are found in muscle tissue, too, not just in neurological tissue. Brain pathology shows characteristic microscopic holes.
CJD is a complex of fatal neurological disorders first described by the two physicians whose names they carry. Some of the disorders are inherited.
Betty Kuffel, MD
Fatal Feast is available on Amazon
Always fascinating, always scary! Thanks for this further education, Betty!