Taipei, April 25 (CNA) Taiwan's experts in neurology and veterinary medicine urged the health authorities Wednesday to reexamine the safety of U.S. beef to human health.
The experts made the call after the United States reported the fourth case since 2003 of mad cow disease, known formally as bovine spongiform encephalopathy (BSE), on its soil.
Kaohsiung Chang Gung Memorial Hospital honorary vice superintendent Chen Shun-sheng, an neurologist serving at the hospital's Department of Neurology, suggested the Department of Health (DOH) freeze U.S. beef trade until the U.S. completes an epidemiological probe into the infected animal.
U.S. agricultural authorities confirmed Tuesday the positive test on the dairy cow, which was randomly selected for testing from a transfer facility in California that sends animals to a rendering plant, and said products from the cow's carcass had not entered the human food chain.
A U.S. official statement said other animals were not affected and the current quarantine level will remain unchanged.
Chen, who had joined governmental mad cow disease assessments during Taiwan-U.S. beef trade talks, criticized the U.S., saying it should not reach a conclusion before an epidemiological investigation has been completed.
"The dairy cow would not have been infected for no reason," he said, noting that currently, there are no answers to questions like whether or not the sick cow had eaten problematic feed, or whether something wrong had happened to the environment where the animal was pastured.
Citing historic records, the neurologist said an infectious agent -- called prion, that can cause BSE -- had been found in milk produced by goats that were infected with mastitis. Therefore, milk from BSE-infected cows cannot be excluded from the risk of spreading mad cow disease, Chen said.
Echoing Chen, Director Yang Ping-cheng of Animal Technology Institute Taiwan said that in the latest mad cow disease case, investigators must find out how old the affected dairy cow was, how many siblings and offspring it had, and why it caught the disease.
Normally, it takes a month to complete such an epidemiological probe, he said.
Yang also said that he could not understand why the diary cow, which has been confirmed at the age of 30 months old, would catch the deadly disease because the U.S. has banned the use of all kinds of animal feed that contains the mixture of meat and bone powder since 2008.
Eating contaminated meat or other animal products from cattle that have BSE is thought to be the cause of the fatal brain disease in humans that is called variant Creutzfeldt-Jakob disease.
The fatal disease was blamed for the deaths of 150 people in Britain, where there were outbreaks in the 1980s and 1990s.
Chou Chin-cheng, dean of National Taiwan University's School of Veterinary Medicine, said since there are doubts on the latest mad cow case in the United States, the government should reevaluate the risk of importing U.S. beef, and reconsider how to keep talking with the U.S. on the controversial issue of beef trade.
(By Chen Ching-fang and Elizabeth Hsu)