Another confirmed 'mad cow' death in Texas
By Judith Pannebaker BCC Editor
This downer cow is symptomatic of bovine spongiform encephalopathy (BSE), or "mad cow" disease, which humans can contract if they consume brains and spinal cords of affected cattle.
A second death from so-called "mad cow disease" has occurred in Texas; however, heath care authorities say there is no cause for alarm.
Medical personnel with the Centers for Disease Control and Prevention in Atlanta, Georgia, working with the Texas Department of State Health Services (DSHS), have confirmed a diagnosis of Variant Creutzfeldt-Jakob Disease (vCJD) - a fatal brain disorder commonly known as "mad cow disease" - in a patient who recently died in Texas. The diagnosis was confirmed when laboratory results from an autopsy of the patient's brain tested positive for variant vCJD, which is characterized by dementia and holes or a spongy appearance in the brain.
First described in 1996 in the United Kingdom, vCJD is a rare, degenerative, fatal brain disorder in humans. Additionally, there is no cure or known treatment of vCJD; it is invariably fatal.
Although unconfirmed, the disease is believed to be caused by consumption of products from cows infected with bovine spongiform encephalopathy (BSE), or "mad cow" disease. However, in three cases from the United Kingdom, infection might have occurred via a blood transfusion from an asymptomatic, infected donor.
Worldwide, more than 220 vCJD patients have been reported, with a majority of them - 177 cases - in the United Kingdom and 27 cases in France. The case in Texas is the fourth to be reported in the United States and the second in this state. In each of the three previous cases, infection apparently took place outside the United States, including two cases from the UK and one from Saudi Arabia. The history of this fourth patient included extensive travel to Europe and the Middle East, supporting the theory that infection occurred outside the US.
The CDC and DSHS investigations will likely confirm further details of the latest patient's history - including the potential source of infection. No information was available on the DSHS website indicated where the latest death due to vCJD had occurred in Texas.
The first patient, who succumbed to vCJD in the US, was born in the UK in the late 1970s and lived there until relocating to Florida in 1992. Symptoms began in November 2001 and the patient died in June 2004. The patient never donated or received blood, plasma or organs; never received human growth hormone; nor did the patient ever have major surgery other than having wisdom teeth extracted in 2001. Additionally, there was no family history of CJD.
The second patient, also a native of the UK, resided in Texas from 2001 to 2005. His symptoms began in early 2005 while living in Texas. He then returned to the UK, where his illness progressed. Variant CJD was diagnosed and confirmed by neuropathology at the time of his death.
While living in the United States, the patient had no history of hospitalization, of having invasive medical procedures or of donating or receiving blood or blood products.
Physicians believe the patient contracted the disease in the UK while living there from 1980 to 1996, the defined "period of risk for human exposure" to the agent causing "mad cow disease." His stay in the United States was too short for the incubation period for vCJD to have occurred here.
Although born and raised in Saudi Arabia, the third patient lived in the US since late 2005. In addition, the patient occasionally stayed in the United States for as long as three months at a time since 2001 and there was a shorter visit in 1989. The patient's onset of symptoms occurred in spring 2006.
In late November 2006, a research team at the University of California San Francisco Memory and Aging Center confirmed this patient's vCJD clinical diagnosis by pathologic study of brain biopsy tissue. The patient had no history of receiving blood, a past neurosurgical procedure or residing in or visiting European countries.
Due to the expected greater-than-seven-year incubation period for food-related vCJD, this patient was most likely infected from confirmed consumption of BSE-contaminated cattle products while living in Saudi Arabia as a child. The patient had no history of donating blood and a public health investigation has identified no known risk of transmission to US residents from this patient.
The latest confirmed death from vCJC occurred in Texas last month. The diagnosis was confirmed when laboratory results from an autopsy of the patient's brain tested positive for vCJD. According to a CDC report, the patient in Texas had traveled "extensively" to Europe and the Middle East.
"There are no Texas public health concerns or threats associated with this case," administrators with DSHS posted on the agency's website. "Infection likely occurred outside the United States."
A surveillance program by the US Department of Agriculture tests brain tissue extracted from approximately 40,000 dead cows annually for BSE, targeting animals considered most at risk.
Another integral part of the US food safety net ensures that animal tissues that carry BSE, such as the brain and spinal cord, are removed from cattle before being processed for food. There is no evidence that people can get "mad cow disease" or vCJD from eating muscle meat - which is used for ground beef, roasts and steaks - or from consuming milk or milk products.
According to the website, ttp://www.everydayhealth.com, people who have spent at least three months in areas where mad cow disease has been found are prohibited from donating blood in the US and Canada.