Creutzfeldt-Jakob disease (CJD) is a fatal, rare disease with fewer than 1,000 cases in the United Starts each year and a prevalence of one in 1-2 million people worldwide annually. We previously reported a total of 5 sporadic CJD cases observed from July 2021 to June 2022 at Corewell Health West in Grand Rapids, Michigan. Here, we report our retrospective study on patients diagnosed with CJD between January 1, 2021, and September 30, 2024 at Corewell Health in Michigan.

We identified 14 CJD patients during this study period. Patients’ age ranged from 65 to 80 years-old with a mean age 73.79. Nine patients were female (64%). The numbers of positive cases were 2, 6, 5 and 1 in 2021, 2022, 2023 and by end of September in 2024, respectively. Thirteen patients had positive RT-QuIC with the likelihood of prion disease greater than 98%. One patient had negative RT-QuIC but a very high T-tau level, eventually was confirmed as sporadic CJD by autopsy. All patients had elevated T-tau level, and 8 patients had levels greater than 20,000 pg/mL.Twelve patients were positive for 14-3-3. Of these, 10 had levels ranging from 30,082 to more than 160,0004 AU/mL; 2 patients were positive but without titers. Two additional cases had inconclusive 14-3-3 results due to sample quality. Seven patients underwent autopsy and were confirmed as sporadic CJD and subtypes included MM1, MV2, VV2 and MV1-2.

Our 45-month retrospective study found 14 CJD cases in Corewell Health, one of the large health systems in Michigan, which challenges the prevailing understanding that CJD is a rare disease. We also found higher incidence of CJD in 2022 and 2023 of unclear etiology. Further studies will be needed to investigate cases with negative RT-QuIC, high T-tau value and positive 14-3-3, to understand the true CJD incidence.