Creutzfeldt–Jakob Disease in Depth

Creutzfeldt–Jakob Disease

A fourth victim has died in the United States from a rare but deadly brain disorder related to mad cow disease. Federal health officials confirmed variant Creutzfeldt-Jakob disease is what led to a Texas man’s death. Because it is still a new disease, variant Creutzfeldt-Jakob disease has yet to be fully examined and understood in depth.

Variant Creutzfeldt-Jakob disease was first reported in 1996 in the United Kingdom. It is an incurable and fatal neurodegenerative disorder that is contracted by consuming beef contaminated with bovine spongiform encephalopathy (BSE) or mad cow disease. Variant Creutzfeldt-Jakob disease is actually what is diagnosed in humans. Mad cow disease os what is diagnosed in the animal.

The disease can only be confirmed upon a biopsy or autopsy of brain tissue. So far, more than 229 cases of the disease have been reported. Most of them have been located in the United Kingdom and France, with only four reported in the U.S. In all four cases, the victims were either from or had traveled to countries known to have BSE contaminated meat. The man who died of the variant Creutzfeldt-Jakob disease in May, traveled extensively to Europe and the Middle East, according the Center for Disease Control (CDC). “There are no Texas public health concerns or threats associated with this case,” said the Texas Department of State Health Services stated.

Mad cow disease affects the brain, spinal cord and nervous system of the bovine animal. In humans it causes symptoms varying from blurred vision, confusion and hallucinations, dementia, impaired speech and muscle twitching. It is passed between cows through recycling bovine meat carcasses for meat and bone protein and feeding it to other cattle.

Not everyone who consumes BSE infected meat contracts variant Creutzfeldt-Jakob disease. According to Dr. Ermias Belay, an associate director for medical epidemiology at the CDC, only 177 human cases resulted from the millions of infected cows that were consumed in the U.K. Typically it affects younger people, and death occurs within about 13 months of initial infection. The median age at death is 28. One reason medical professionals and scientists have not been able to study variant Creutzfeldt-Jakob disease in depth is due to the low number of people who contract the disease.

Variant Creutzfeldt-Jakob disease is often confused with Classic Creutzfeldt-Jakob disease (CJD), another degenerative neurological disorder that develops when normal prion proteins spontaneously transform into abnormal prions. Unlike variant Creutzfeldt-Jakob disease, it has nothing to do with BSE contaminated meat. It is a sporadic disease that affects persons over 60-years-old worldwide. Death occurs within four to five months of initial infection and the median age at death is 68.

CJD has been recognized since the 1920s. About five to 15 percent of people who develop CJD do so because of inherited mutations of the prion protein gene. Since 1970, the death rate has steadily increased from less than 200 deaths to nearly 400 in 2010. Symptoms of CJD include personality changes, memory loss, anxiety, and difficulty speaking and swallowing.

Diagnostic tests for CJD include a CT scan of the brain, a brain MRI, and a spinal tap to test for proteins, or an electroencephalogram. However, like variant Creutzfeldt-Jakob disease, the only way to confirm CJD is with a biopsy or autopsy.

Although there are two very different and distinct types of Creutzfeldt-Jakob disease, they do share symptoms, and they can only be confirmed postmortem. CJD is spontaneous and sporadic, and variant Creutzfeldt-Jakob disease is what results from human consumption of BSE contaminated beef. Although variant Creutzfeldt-Jakob disease has not yet been studied in depth and fully understood, it is safe to presume it has not been contracted in the United States.

By Brandi M. Fleeks

Sources:
Center for Disease Control Medical Daily
Texas Department of State Health Services
CNN
Mayo Clinic
World Health Organization

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