Source: CNN.com

Mad cow disease has caused a fourth death in the United States, health officials say.

Lab tests have confirmed that a patient in Texas who recently died had Variant Creutzfeldt-Jakob Disease. Variant CJD is a fatal brain disorder linked to eating beef from cattle with mad cow disease, the Centers for Disease Control and Prevention (CDC) said in a press release.

Variant CJD was first identified in the United Kingdom in 1996, according to the CDC. Worldwide more than 220 cases have been reported, the majority in Europe. CDC officials said this is only the fourth case to be reported in the United States, and that each U.S. infection is believed to have happened while the patient was traveling abroad.

The Texan patient traveled "extensively" to Europe and the Middle East, the CDC said.

"There are no Texas public health concerns or threats associated with this case," the Texas Department of State Health Services posted to its website.

Variant CJD is different than what the CDC calls classic CJD, which is not related to mad cow disease. Classic CJD strikes less than 400 Americans each year. It is also fatal.

Mad cow disease is officially called bovine spongiform encephalopathy, or BSE. Animals with BSE have infectious prions in their brain, spinal cord and some parts of the central nervous system. These prions can be spread to humans who eat those specific parts of the cow, or who eat meat that has come in contact with infected tissue or that has been processed in contaminated machinery.

Eating meat contaminated with the disease is thought to be the cause of Variant CJD in humans. The first case of mad cow disease was confirmed in a cow in the United States in December 2003.