Spongiform encephalopathies - The prion's perplexing persistence

Exposure to infectious prions does not always lead to clinical disease, but a new report indicates that prions can nonetheless persist in the brain. Hamster prions were injected into mice and, although the mice did not develop symptoms, the prions were present for almost the entire life of the mice. What's more, when brain extracts from these mice were injected back into hamsters, the hamsters showed clinical symptoms. These findings could have public-health implications — for example, pigs and poultry, which do not develop disease after eating bovine prions, may be acting as reservoirs for the infectious agent.