Investigators search for mad cow source

INVESTIGATORS are combing Canadian feed mills and rendering plants to try to pinpoint the source of infection for the BSE-infected Washington state cow.

Meanwhile, US officials trying to contain the outbreak of the disease said a Washington state farm already under quarantine was also home to nine other cows that entered the United States from Canada in 2001 with the infected Holstein. The Mabton farm was the diseased cow’s final home and also had one of its calves.

Mad cow disease is a concern because humans can develop a brain-wasting illness, variant Creutzfeldt-Jakob disease, from consuming infected beef products. The US Centres for Disease Control and Prevention said 153 people worldwide, most of them in Britain, had contracted the human form of the illness since the mid-1990s.