L O N D O N, Aug. 3, 2000 -- The number of people contracting the human form ofmad cow disease has increased by about 23 percent a year in Britainsince 1994, new research has found.
The findings, published this week in The Lancet medical journal,are part of scientists’ effort to determine the scope of variantCreutzfeldt-Jakob Disease, a fatal brain-wasting disease.
They are struggling to make accurate predictions about how largethe epidemic will be or when it will reach its peak because theydon’t know the incubation period of the disease. It could laydormant for 20 years without being detected.
Diagnosis of the Deceased
The disease, which experts think comes from eating beefcontaminated with the cattle ailment bovine spongiformencephalopathy, can only be confirmed by examining the brains ofvictims after they have died.
The scientists have had to establish the onset of the infectionby asking the victims’ relatives when symptoms first occurred.
Experts don’t know exactly how long it takes between becominginfected and getting symptoms, and the lag between becoming sickand dying has varied.
The study, by scientists at the London School of Hygiene andTropical Medicine and the National CJD Surveillance Unit, alsofound that deaths from variant CJD have risen by about a third eachyear since 1994, slightly faster than the increase in the onset ofthe disease. Researchers don’t know why deaths are rising fasterthan the incidence.
As of June 30, a total of 75 confirmed or suspected cases havebeen documented. Sixty-nine of those people have died.
Canadians Could Catch Mad Cow
The research said 14 people have died of the disease in thefirst six months of this year, compared with 18 deaths for thewhole of 1998.
“Although absolute numbers remain low, there appears to be areal increase in the incidence … in the U.K., which is a causefor concern,” said Dr. Hester Ward of the surveillance unit, basedin Edinburgh, Scotland.
“Until it is known whether this increasing trend is maintainedover time, it is difficult to predict future numbers of cases,”she said.
The disease first surfaced in the mid-1990s, a decade after avet discovered Britain’s first BSE-infected cattle herd.
Since the British outbreak, which affected some 180,000 cattle,about 200 cases have been found in Portugal and smaller numbers inIreland, Belgium, Luxembourg, the Netherlands, France, Denmark andSwitzerland.
A European Union report concluded Tuesday that cases of mad cowdisease are unlikely to occur in the United States and Canada, butcannot be ruled out.
Last month, U.S. Agriculture Secretary Dan Glickman ordered theslaughter of 376 sheep originating from Belgium on suspicion theymay have a mad cow-type disease.