A
Anonymous
Guest
~SH~ said:
Looks to me like USDA thinks that opening the border to Canada will allow entry of BSE positive cases.....
DR. JOHN CLIFFORD:
If an infected cow from Canada were to be imported into the United States, in order for that bovine to transmit infection to a U.S. cow a series of additional safeguards would have to fail or be breached. Even if by small chance BSE-infected material were to make it past the first mitigation, it is highly unlikely that the material would eventually infect a U.S. animal.
It is important to remember that these individual safeguards or steps in the risk pathway should not be considered in isolation. The impact of any specific step depends on its relationship to the others in the sequence. In other words, none of the steps should be considered by itself to represent the entire risk.
As part of the risk assessment, we estimated the prevalence of BSE and the standing adult cattle population of Canada with the same methods that we recently used to estimate the prevalence of BSE in the United States. This estimate incorporating information about the expected effects of the feed ban is 6.8 infected animals per 10 million adult cattle.
We then used this current estimate of prevalence to help assess the likelihood that BSE would be introduced or released over an extended period of time. We chose to evaluate what could happen over the next 20 years, assuming the proposed rule would apply into the foreseeable future. First, we looked at the most likely scenario, given that Canada has had a feed ban in place since 1997, and evidence indicates that the implementation of the feed ban results in decreasing BSE prevalence. The most likely scenario is that BSE prevalence in Canada will continue to decrease over the next 20 years.
This decrease, combined with the mitigative effects of our import requirements and the young age of animals at the time of import, would continuously decrease the possibility that infected animals would be imported over the 20-year period.
Under this scenario, the likelihood of BSE exposure and establishment in the U.S. cattle population, as a consequence of importing infected Canadian cattle, is negligible.
We then considered other less-likely scenarios that may overestimate the overall risk. In these less-likely scenarios we assumed that BSE prevalence in Canada would remain constant during the next 20 years. This would mean the continued detection of infected animals born after the implementation of the feed ban and during the entire 20-year timeframe.
Even with these less-likely scenarios, our assessment indicates that BSE will not be spread or become established in the United States as a result of the proposal. Although our risk assessment was conducted to evaluate animal health risk, we did use one model in our assessment to also consider possible impacts on public health.
The results of this model indicated that these potential impacts are extremely low. As you know, public health in the United States is protected through slaughter practices, including the removal of specified risk materials, and the feed ban.
In conclusion, for all commodities considered under the current proposal, the risk of BSE-infectivity is negligible and the disease will not become established in the United States. This is true If an infected cow from Canada were to be imported into the United States, in order for that bovine to transmit infection to a U.S. cow a series of additional safeguards would have to fail or be breached. Even if by small chance BSE-infected material were to make it past the first mitigation, it is highly unlikely that the material would eventually infect a U.S. animal.
It is important to remember that these individual safeguards or steps in the risk pathway should not be considered in isolation. The impact of any specific step depends on its relationship to the others in the sequence. In other words, none of the steps should be considered by itself to represent the entire risk.
As part of the risk assessment, we estimated the prevalence of BSE and the standing adult cattle population of Canada with the same methods that we recently used to estimate the prevalence of BSE in the United States. This estimate incorporating information about the expected effects of the feed ban is 6.8 infected animals per 10 million adult cattle.
We then used this current estimate of prevalence to help assess the likelihood that BSE would be introduced or released over an extended period of time. We chose to evaluate what could happen over the next 20 years, assuming the proposed rule would apply into the foreseeable future. First, we looked at the most likely scenario, given that Canada has had a feed ban in place since 1997, and evidence indicates that the implementation of the feed ban results in decreasing BSE prevalence. The most likely scenario is that BSE prevalence in Canada will continue to decrease over the next 20 years.
This decrease, combined with the mitigative effects of our import requirements and the young age of animals at the time of import, would continuously decrease the possibility that infected animals would be imported over the 20-year period.
Under this scenario, the likelihood of BSE exposure and establishment in the U.S. cattle population, as a consequence of importing infected Canadian cattle, is negligible.
We then considered other less-likely scenarios that may overestimate the overall risk. In these less-likely scenarios we assumed that BSE prevalence in Canada would remain constant during the next 20 years. This would mean the continued detection of infected animals born after the implementation of the feed ban and during the entire 20-year timeframe.
Even with these less-likely scenarios, our assessment indicates that BSE will not be spread or become established in the United States as a result of the proposal. Although our risk assessment was conducted to evaluate animal health risk, we did use one model in our assessment to also consider possible impacts on public health.
The results of this model indicated that these potential impacts are extremely low. As you know, public health in the United States is protected through slaughter practices, including the removal of specified risk materials, and the feed ban.
In conclusion, for all commodities considered under the current proposal, the risk of BSE-infectivity is negligible and the disease will not become established in the United States. This is true even if Canada identifies additional cases of BSE and even if an infected animal were to be imported to the United States.
http://www.usda.gov/wps/portal/!ut/p/_s.7_0_A/7_0_1OB?contentidonly=true&contentid=2007/01/0002.xml