LONDON, England (Reuters) - British doctors investigating a local cluster of "mad cow" deaths in the central English village of Queniborough said on Wednesday that meat appeared to be the common cause of the five fatalities.
The inquiry, launched in July to find vital clues about what may cause new variant Creutzfeldt-Jakob Disease (CJD), the human form of the brain-wasting disease, is due to last until next March, but interim findings have been released.
"It (meat) is the only factor that we can establish that potentially links all the cases," said Dr. Phillip Monk, who is leading the study.
"When you investigate a cluster what you're really looking for is a common link between all the cases."
He said that the report had dismissed the possibility that CJD was transmitted through water supplies, animal bites or immunization.
"They may be relevant factors for other people with variant CJD, but they don't explain our cluster," Monk told BBC radio.
He added that the inquiry would now focus on tracking down how the meat entered the food chain.
"We know for sure they (the victims) didn't use one common butcher," he said. "We've got to go from the farmgate to the butcher shops to see where these links might be."
Mad cow disease, or bovine spongiform encephalopathy (BSE) was first identified in 1986, provoking a crisis that is expected to have cost Britain four billion pounds by 2001.
A total of 85 people in Britain have died from the new variant CJD, the human form of BSE, and some scientists fear that the number of cases may rise to thousands.
The British government said many of the Queniborough CJD victims would have been exposed to the infective agent "many years ago." Most were believed to have contracted the fatal disease in the late 1980s through eating infected meat.
But scientists are still divided on the cause of BSE in cattle and its route to humans. Most believe it is caused by prion proteins which set up a deadly chain reaction.