Creutzfeldt - Jakob Disease in South West Sydney 2014-2020: An Unusually High Incidence of a Rare Disease

Introduction Creutzfeldt - Jakob Disease (CJD), a spongiform encephalopathy, caused by a transmissible misfolded cellular prion protein is a rapidly progressive, debilitating neuro-degenerative disorder with no effective treatment. The estimated global incidence is at 1/ million inhabitants. This retrospective study examined the incidence of CJD in South Western Sydney Local Health District (SWSLHD) from 2014 to 2020. Background SWSLHD had an estimated population of 1,038,534 in 2020, with CJD data being limited. Methods New South Wealth (NSW) Health-Information-Exchange (HIE) database, for all admissions with CJD diagnoses in SWSLHD, between 2014–2020, was reviewed according to World Health Organization (WHO) diagnostic criteria, consistent with the Australian national CJD registry. Only probable CJD cases were included. Incidence was calculated based on the projected SWSLHD population. Results 35 patients, diagnosed with CJD, were identified. Each was evaluated by two independent investigators, including clinical presentation; MRI; EEGs; 14-3-3; and RT-QUIC results, before assigning CJD-probable status. Four failed the CJD criteria and were excluded. Of the 31 CJD-probable cases, most (59%) were male and older (37% range 61-70 years). The incidence rate peaked at 9/million in 2017 and was above 2/million, throughout the seven years, with an average of 4.859/million/year. Conclusions The incidence of CJD, in SWSLHD, exceeds the national average of 1/million. Cost-effective, adequate diagnostic and screening tools, implementable over a large population, will become increasingly essential.