EMERGING & RE-EMERGING INFECTIOUS DISEASES
PRION DISEASES
DEADLY CJD
SCENARIO 011
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Degenerative, fatal brain disorder, variant CJD, kills Texas man, 4th in the U.S.
A diagnosis of variant CJD (a fatal brain disorder) in a patient who recently died in Texas has been confirmed after laboratory tests of an autopsy of the patient’s brain, reported CDC.
Variant CJD is a rare, degenerative, fatal brain disorder in humans, first discovered in 1996 in the United Kingdom. It is believed to be caused by consumption of products from cows with the disease bovine spongiform encephalopathy (BSE, or “mad cow” disease).
At least 220 variant CJD patients have been reported worldwide, with a majority of them in the United Kingdom (177 cases) and France (27 cases).
The latest fatality is the fourth to be reported in the United States. In each of the three previous cases, infection likely occurred outside the United States, including the United Kingdom (2 cases) and Saudi Arabia (1 case).
“The history of this fourth patient, including extensive travel to Europe and the Middle East, supports the likelihood that infection occurred outside the United States.”
The disease also spread to many other European countries, and cases in cattle have been identified outside of Europe, in Canada, Israel and Japan, said CDC.
In 2012, health officials confirmed that a dairy cow in California’s Central Valley had bovine spongiform encephalopathy (BSE), commonly referred to as the mad cow disease, but insisted that the US beef and dairy products were safe.
- BSE is a fatal neurodegenerative disease in cattle that can be easily passed on to humans; it has an incubation period of up to 8 year in cattle and about 12 years in humans.
- The disease is easily transmitted to humans by eating food contaminated with the brain, spinal cord or digestive tract of infected carcasses.
- An outbreak of BSE in the United Kingdom killed at least 166 people (an additional 50 known fatalities occurred in other countries) and about 180,000 cattle in the 1980s, and forced the authorities to destroy about 4.5 million cows at cost of more than $7 billion.
- BSE prion is not destroyed through cooking and can be transmitted to humans who consume contaminated beef products.
- An estimated half a million cattle infected with BSE entered the human food chain in the 1980s.
- A second strain of BSE prion, discovered in 2004, may have also entered the food chain.
- The diseased animal was he first confirmed case of mad cow disease in the U.S. in 6 years.
- The first known case of BSE infection in North America was reported in Alberta, Canada in 1993.
- South Korea has suspended sales of U.S. beef on Wednesday.
Update from APHIS Regarding a Detection of Bovine Spongiform Encephalopathy (BSE) in the United States
On April 24, 2014 USDA’s Animal and Plant Health Inspection Service confirmed the nation’s 4th case of Bovine Spongiform Encephalopathy (BSE) in an animal that was sampled for the disease at a rendering facility in central California.
Through its continuing epidemiological investigation, APHIS–in collaboration with the California Department of Food and Agriculture (CDFA)–has identified that one progeny born to the positive cow in the last 2 years was stillborn, and another has been located on a site in another state.
Update: Variant Creutzfeldt-Jakob Disease in a U.K. Citizen Who Had Temporarily Resided in Texas, 2001-2005
In November 2005, the U.K. National Creutzfeldt-Jakob Disease (CJD) Surveillance Unit in Edinburgh, Scotland notified the Centers for Disease Control and Prevention (CDC) about a probable variant CJD diagnosis in a 30-year-old man who resided in Texas during 2001-2005. The patient had onset of symptoms in early 2005 while in Texas. He then returned to the United Kingdom, where his illness progressed, and a diagnosis of variant CJD was made. This diagnosis was confirmed neuropathologically after the patient’s death.
About BSE [mirrored from CDC site]
BSE (bovine spongiform encephalopathy) is a progressive neurological disorder of cattle that results from infection by an unusual transmissible agent called a prion. The nature of the transmissible agent is not well understood. Currently, the most accepted theory is that the agent is a modified form of a normal protein known as prion protein. For reasons that are not yet understood, the normal prion protein changes into a pathogenic (harmful) form that then damages the central nervous system of cattle.
Research indicates that the first probable infections of BSE in cows occurred during the 1970’s with two cases of BSE being identified in 1986. BSE possibly originated as a result of feeding cattle meat-and-bone meal that contained BSE-infected products from a spontaneously occurring case of BSE or scrapie-infected sheep products. Scrapie is a prion disease of sheep. There is strong evidence and general agreement that the outbreak was then amplified and spread throughout the United Kingdom cattle industry by feeding rendered, prion-infected, bovine meat-and-bone meal to young calves.
The BSE epizootic in the United Kingdom peaked in January 1993 at almost 1,000 new cases per week. Over the next 17 years, the annual numbers of BSE cases has dropped sharply; 14,562 cases in 1995, 1,443 in 2000, 225 in 2005 and 11 cases in 2010. Cumulatively, through the end of 2010, more than 184,500 cases of BSE had been confirmed in the United Kingdom alone in more than 35,000 herds.
There exists strong epidemiologic and laboratory evidence for a causal association between a new human prion disease called variant Creutzfeldt-Jakob disease (vCJD) that was first reported from the United Kingdom in 1996 and the BSE outbreak in cattle. The interval between the most likely period for the initial extended exposure of the population to potentially BSE-contaminated food (1984-1986) and the onset of initial variant CJD cases (1994-1996) is consistent with known incubation periods for the human forms of prion disease.
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