Yale Medicine In April of this year, three people in Oregon developed Creutzfeldt-Jakob disease (CJD), a rare, fatal neurological condition that is similar to bovine spongiform encephalopathy, also known as mad cow disease. It impacts one or two people per million each year, making the chances of three cases emerging in the same small geographic area quite low. This outbreak is currently under investigation, but there may not be a simple explanation; for the majority of CJD cases, the infectious source is unknown.
CJD and mad cow disease are both transmissible spongiform encephalopathies, named for the sponge-like holes that compromise the brain as the disease progresses. These diseases can have long latency periods; CJD can remain dormant for up to 38 years, but once it spreads to the brain, it decimates the brain and kills its host.
An abnormally folded protein—called a prion—is the hallmark of neurodegeneration in CJD. Once formed, prions can’t be cleared, leading to a build-up of aggregated proteins that damage the brain. Some researchers believe the prions themselves are infectious, but Laura Manuelidis, MD, a professor of surgery (neuropathology) at Yale School of Medicine, suspects misfolded prions are a late-stage response to an infectious agent, such as a small virus. In a new study, published May 28 in PLOS One, Manuelidis and her colleagues developed the first cellular model of a latent CJD infection, revealing key pieces of the puzzle.