June 1, 2006

 

OIE changes definitions of mad-cow risk

 

 

The World Organisation for Animal Health (OIE) last week revised the three definitions of risk categories for countries affected by mad cow disease at its Annual General Session held in Paris from May 21 to 26.

 

The three definitions are - negligible risk, controlled risk, and undetermined risk of cattle being infected with the disease.

 

Previously, a country that reported a case had to wait seven years from the date of its latest discovery before being eligible to be classified as a negligible-risk country, the category at the least risk from the disease.

 

This meant that the US would have to wait until 2013 to be classified as a negligible-risk country as its latest case was discovered in March this year.

 

Now, the clock starts from the date of birth of the infected animal.

 

The General Session was attended by representatives appointed by the governments of the 167 OIE member countries.

 

The US cattle industry said the change more accurately reflects the scientific knowledge surrounding the disease.

 

Since the disease is caused by feeding contaminated animal-based feed to cattle, and cattle are most likely to become infected during the first year of their lives, using the animal's birth date as a reference point allows countries to determine how long contaminated feed may have been in the system.

 

OIE is now saying countries with adequate testing programmes that detect no cases in cattle born within the past 11 years should be considered as a negligible risk because there is no evidence the disease has been recycling in the feed supplies of those countries.

 

By applying this new reference point to the US, which has tested over 720,000 cattle and detected two infected animals born more than 10 years ago, evidence suggests that while the disease may have been present before the US implemented its 1997 feed ban, the fact that no cases have been detected in cattle born after that suggests that the US has halted the disease 

 

R-Calf, a US cattle association views the OIE's new standard as support for the organization's position that the risk of mad cow disease in Canadian beef is greater than the risk of disease in US beef.

 

Of the six cases detected in Canada after testing less than 110,000 cattle since 2004, half of them were born after the 1997 implementation of its feed ban, which suggests a continuing BSE problem in that country, a representative from the organisation said.

 

The organization has been lobbying the US Department of Agriculture for two years to reverse a decision that allows Canadian beef to be imported into the United States.