Geographical Analysis of the Sporadic Creutzfeldt-Jakob Disease Distribution in the Autonomous Community of the Basque Country for the Period 1995-2008

Background: The Basque Country, in Spain, shows one of the highest sporadic Creutzfeldt-Jakob disease (sCJD) incidence rates in Europe. The purpose is to analyse a possible focus of unidentified external or environmental factors which could trigger the high incidence rates of sCJD in the Basque Country. Methods: We estimated the relative risk and the posterior relative risk distribution of sCJD cases for each town of the Basque Country and for the period 1995-2008. Results: 58 sCJD cases (44 definite and 14 probable) were selected for the geographic cluster analysis. In a first approach, referring to the relative risk, several municipalities in the Autonomous Community of the Basque Country showed more sCJD cases than expected. However, the posterior relative risk distribution showed no excess risk areas. Conclusions: Results from this survey indicate that a possible common source of development of the disease does not seem to be the reason of the high sCJD incidence.