Link Between Mad Cow Disease and Human Deaths Questioned
"It is unlikely that human beings who eat prions from other species are likely to get infected, because our own defenses are well enough organized to digest or to destroy these prions," he says.
But prion researcher Robert B. Petersen, PhD, disagrees and says while some of Venters' assumptions may seem valid on paper, they just don't reflect what is going on. Petersen says studies have shown that the molecular signatures of BSE and new variant CJD are virtually identical. And animal studies have confirmed the pathological similarities of the two diseases. Petersen is an associate professor of pathology at Cleveland's Case Western Reserve University and is chief scientific officer for a company working to develop a diagnostic test for BSE.
Petersen tells WebMD that by looking at all the features of the disease, it's clear that there are different types of CJD. The new variant CJD doesn't appear to be like anything that occurred before doctors started to study BSE.
People may argue that by now, doctors should be seeing more people sick with variant CJD, Petersen says. But in order to make such an assumption, scientists have to know a lot more about the disease than they do today, such as how long it takes to show signs of the disease after becoming exposed to it. That period of time could be anywhere from 10 to 60 years, Petersen says. "We just don't know at this point."
Similarly, there is no way to know whether an epidemic of new variant CJD will occur in years to come among people who may have already been infected, he says.