WASHINGTON — The U.S. Department of Agriculture (USDA) found an atypical case of Bovine Spongiform Encephalopathy (BSE), a neurologic disease of cattle, in an eleven-year old beef cow in Alabama.
This animal never entered slaughter channels and at no time presented a risk to the food supply, or to human health in the United States.
USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Laboratories have determined that this cow was positive for atypical (L-type) BSE.
The animal was showing clinical signs and was found through routine surveillance at an Alabama livestock market. Following delivery to the livestock market the cow later died at that location. Routine tissue samples were taken and sent to diagnostic laboratories in Colorado and Iowa for testing and confirmation.
The results were confirmed for atypical BSE at the USDA laboratory in Ames, Iowa.
Types of BSE
BSE is not contagious and exists in two types — classical and atypical. Classical BSE is the form that occurred primarily in the United Kingdom, beginning in the late 1980s, and has been linked to variant Creutzfeldt-Jakob disease (vCJD) in people.
The primary source of infection for classical BSE is feed contaminated with the infectious prion agent, such as meat-and-bone meal containing protein derived from rendered infected cattle.
Regulations from the Food and Drug Administration (FDA) have prohibited the inclusion of mammalian protein in feed for cattle and other ruminants since 1997 and have also prohibited high risk tissue materials in all animal feed since 2009.
Atypical BSE is different, and it generally occurs in older cattle, usually 8 years of age or older. It seems to arise rarely and spontaneously in all cattle populations.
Fifth U.S. case
This is the nation’s fifth detection of BSE. Of the four previous U.S. cases, the first was a case of classical BSE that was imported from Canada; the rest have been atypical (H- or L-type) BSE.
The World Organization for Animal Health (OIE) has recognized the United States as negligible risk for BSE. As noted in the OIE guidelines for determining this status, atypical BSE cases do not impact official BSE risk status recognition as this form of the disease is believed to occur spontaneously in all cattle populations at a very low rate.
Therefore, this finding of an atypical case will not change the negligible risk status of the United States, and should not lead to any trade issues.