Whatever Happened to Mad Cow Disease?

     Back in 1986 there was an outbreak of bovine spongiform encephalopathy (also known as Mad Cow Disease) that was first reported in the United Kingdom and peaked in 1993 with almost 1,000 new cases per week. In 1996, variant Creutzfeldt-Jakob Disease was detected in humans and linked to the mad cow epidemic. Eating contaminated meat and cattle products is presumed to be the cause. 

     It's a progressive neurologic disease of cows, meaning it gets worse over time and it damages a cow’s central nervous system (brain and spinal cord).    

     For reasons that are not completely understood, the normal prion protein changes into an abnormal , harmful form and the body of a sick cow does not even know the abnormal prion is there so the cow’s body cannot fight off the disease. 

     A common sign of the disease is the sick cow is uncoordinated and has trouble walking and getting up. A sick cow may also act very nervous or violent. 

     It usually takes four to six years from the time a cow is infected before it first shows symptoms. During this incubation period there is no way to tell that a cow has mad cow disease by looking at it. And, there is no reliable way to test for the disease in a live cow. Once a cow starts to show symptoms, it gets sicker and sicker until it dies, usually within two weeks to six months. There is no treatment and no vaccine to prevent i the disease. 

     How does it spread? Parts of a cow that are not for human consumption can be cooked, dried and ground into a powder which is then used for a variety of purposes, including an ingredient in animal feed. A cow then gets infected by eating the contaminated feed. Since August 1997, the FDA has not allowed most parts from cows and certain other animals to be used to make food that is fed to cows. This protects healthy cows by making sure that the food they eat is not contaminated with the abnormal prion. 

     Common methods to eliminate disease-causing organisms in food, like heat, do not affect prions. Prions can survive in extremes, requiring upwards of 1,800 degrees of heat to be neutralized. Even sterilization processes used by hospitals are largely ineffective.     

     People can get a version of Mad Cow Disease that is called Creutzfeldt-Jakob disease. As of 2019, 232 people worldwide were known to have become sick with it and they all died. 

     It is believed they they got the disease from eating food made from sick cows. Most of the people who have gotten sick lived in the United Kingdom at some point in their lives. Only four lived in the United States and most likely, they became infected when they were living or traveling overseas.

     Neither disease, cow or human, is contagious and research studies have shown that people cannot get sick from drinking milk or eating dairy products, even if the milk came from a sick cow.

    The human variant of the disease, for which there is no cure, can also cause brain damage and lead to psychotic behavior, dementia and coma. In humans it can take up to 15 years for symptoms to manifest themselves and some studies indicate that it might be possible for symptoms to develop up to 50 years after infection! People usually die within 13 months of showing symptoms. Symptoms include tingling sensations and trouble moving parts of the body. As the disease worsens, the victim will lose the ability to walk.

     When Mad Cow Disease broke out in the United Kingdom there was panic. People stopped eating red meat which was pulled from supermarket shelves. Generally, a human will only be infected if they eat the nerve tissue (brains or spinal cord) of an infected animal. Eating muscle meat like ground beef or steak or by drinking milk from an infected cow won't transmit the disease to humans. 

     However, if you are a blood donor who has spent more than 3 months in an area where many cases of mad cow disease have been reported aren’t allowed to give blood in the U.S. 

     Cows and humans aren't the only ones that can get the disease. Sheep, goats, mink, deer and elk can get sick with their own versions. Also, cats are the only common household pet known to have a version of Mad Cow Disease...it's called Feline Spongiform Encephalopathy. Fortunately, no cat in the United States has ever been found to have this disease.