What is CJD?

According to F. Perry Wilson, an associate professor of medicine and public health and director of Yale University's Clinical and Translational Research Accelerator, CJD is a brain disease induced by prions, which are misfolded proteins that aggregate in cells. These prions catalyze the conversion on non-misfolded cells into its own misfolded configuration, which leads to a chain reaction, causing an accumulation of different misfolded proteins and ultimately cell death.

About 85% of cases are sporadic and 15% are genetic, and around 70% of people with CJD die within 1 year.

Prions also cause "mad cow disease," which was first identified in the 1990s, however sporadic CJD is far more common, responsible for 85% of all cases of prion-induced brain disease, Wilson said.

CJD cases are on the rise

For this study, researchers from Johns Hopkins School of Medicine looked at data from CDC's WONDER database and found CJD codes listed on 317 death certificates in 2007 and 502 in 2020.

In total, CJD codes were present on 5,882 death certificates between 2007 and 2020, with 51.2% of all cases occurring among women. During that same period, the incidence of CJD increased from 1.06 to 1.58 per million in women and from 1.05 to 1.47 per million in men.

Men ages 55 to 64 were the only male age group that saw a significant rise of CJD rates, while women saw a significant rise in all age groups between 55 and 84.

Why are CJD cases rising?

According to Wilson, there are three possible reasons why cases of CJD are increasing in the United States.

First, it's possible there's been an increase in those who are most at-risk with the disease, specifically older people, as the population has aged over time.

It's also possible that scientists are better at diagnosing CJD than they have been in the past. Wilson noted that, since the mid-1990s when CJD was first discovered and mostly diagnosed based on symptoms, more advanced MRI protocols have been developed as well as a diagnostic test called "real-time quaking induced conversion testing." All of this could mean we're better at detecting CJD, and as a result, case numbers have increased.

Finally, Wilson notes it's possible a new exposure of some kind has occurred. However, it's not possible to know currently what that exposure could be or where it could come from.

Because the study was limited by its reliance on death certificate data, miscoding or misdiagnosis may have occurred, Probasco and co-authors acknowledged. However, given the findings of the study, Wilson said it's apparent that "a bit more surveillance for this rare but devastating condition is well merited." (Wilson, Medscape, 12/11; George, MedPage Today, 12/11)

Although clinical use of artificial intelligence (AI) is still limited, the technology may be beneficial in diagnosing rare diseases, which are often misunderstood or overlooked by regular doctors, Bina Venkataraman writes for the Washington Post.