Creutzfeldt-Jakob disease surveillance in Eastern Slovakia from 2004 to 2016.

Objectives: An extraordinary incidence of genetic Creutzfeldt-Jakob disease (gCJD) appearing in clusters in the Slovak Republic was described in the 1990's. The aim of the study was to analyse data of CJD cases obtained from surveillance in Eastern Slovakia (ES) (2004-2016), the region outside the described geographical clusters.

Methods: The database set in the project was the source for epidemiological and clinical analysis of CJD cases.

Results: The incidence of CJD in ES (2004-2016) was 1.7/million person-years (95% CI 1-2.4); the incidence increase in the last five years (2012-2016) was comparable to the whole country. Twenty seven of 29 reported CJD cases were available for analysis (mean age 59 years, F/M 15/12). The proportion of gCJD (E200K mutation) cases remained dominant (78%), with 9 familiar cases originating in 4 families. Analysis of the clinical features revealed shorter duration of the symptomatic phase in sporadic CJD (sCJD) (3.4 months) versus gCJD (5.15 months). Cognitive/behavioural changes, insomnia, and sensory disturbance were more pronounced in the early symptoms of gCJD. Periodic EEG discharges were more frequent in sCJD (83%) than gCJD (56%), all 19 available MR findings were CJD specific and localisation of abnormalities varied amongst the CJD forms.

Conclusions: The surveillance of CJD in ES (2004-2016) showed an increased incidence of CJD in ES, reaching the incidence rate of the whole country, with a permanent proportion of 70% gCJD cases based on the E200K mutation. Clinical, electrophysiological and MR features of sCJD and gCJD cases were in conformity with already published data. Epidemiological analysis of CJD in ES shows increasing detection of CJD but also suggests that current routine surveillance systems for CJD may underestimate the true burden of disease, especially sporadic cases in Slovakia.