As USDA and other officials continue their investigation of the BSE case discovered in California last month, Dr. John Clifford, chief veterinary officer for USDA’s Animal and Plant Health Inspection Service, spoke with Agri-Talk Radio’s Mike Adams on Thursday.
Clifford verified that two dairies currently are under quarantine, a routine procedure during a BSE investigation. USDA and California Department of Agriculture officials are examining records at the two farms to determine whether the herds include any birth cohorts of the BSE cow. Once they complete that determination, the general quarantine would be lifted and only the birth cohorts would be subject to quarantine.
Officials also investigated the cow’s offspring from the past two years. One calf was stillborn, and the other was located in an unidentified dairy. USDA purchased that animal, euthanized it and sent samples to the APHIS laboratory in Ames, Iowa for testing. Those tests confirmed the animal was negative for BSE.
Asked whether the agency can rule out feed as a potential cause of the BSE case, Clifford says that while these rare “atypical” cases of BSE are not well understood, there is no evidence feed is involved. Sporadic forms of spongiform encephalopathy diseases similar to BSE have been identified in humans and in sheep as well as cattle, with genetics a possible factor. About 60 cases of atypical BSE have been identified worldwide.
He also points out that our ban on feeds containing ruminant-derived products, in place since 1997, and the removal of specific risk materials from slaughtered cattle, make it highly unlikely cattle could contract BSE from feed. He points to a 99 percent reduction in cases of “classical” BSE worldwide since the peak in 1992, with only 29 cases of classical BSE identified worldwide from 1992 through last year.
Clifford says USDA tests about 40,000 cattle per year, for BSE, with testing focused on high-risk animals such as those that present with clinical, neurological signs that could be associated with BSE. The agency also uses random surveillance targeting animals that either died or were euthanized due to other health problems and ship to rendering facilities. The level of testing is sensitive enough to detect BSE at a prevalence of one case per million animals.
It would be possible to test every animal, Clifford says, but it would be impractical. The system is built on three critical components. Testing is one component. The feed ban greatly reduces the possibility of BSE in cattle, and the third component – removal of specific risk materials – protects human health. “I’m very confident the procedures we have in place are working,” Clifford says, adding that the agency continues to review current science and knowledge of the disease and will adjust in the future if research identifies more effective methods.
Asked about any concerns over milk safety, Clifford stressed that BSE “does not affect milk at all.”
With regard to communications with our trading partners and specifically with South Korea, Clifford said he and other officials met with a Korean delegation this week in Maryland. The Korean group then visited the USDA lab in Ames, Iowa, and today is in California meeting with state and federal animal-health officials and visiting the laboratory that diagnosed the latest BSE case.