Apparently Kuru, a similar fatal brain-wasting prion disease that has been found in New Guinea, has been discovered to have an incubation period of 35 to 41 years and researchers suspect it could be longer for vCJD because the infection is transmitted between cows and humans, which are two different species.
The 160 fatal human cases of the disease that are already known about could represent a distinct genetic subgroup of the population with an unusually short incubation period, according to John Collinge, the study leader and a professor at University College, London, and he explained there could be "substantial underestimations" in recent estimates of the size of the vCJD epidemic.
