title: [Creutzfeldt-Jakob syndrome in the county of Storstrom during the period 1990-1999. Was there a significant accumulation of cases?].
abstract: BACKGROUND
  In the county of Storstrøm with about 250,000 inhabitants, ten cases of Creutzfeldt-Jacob disease (CJD) were diagnosed at the Department of Neurology, Naestved County Hospital during the decade 1990-1999. Only one case is to be expected every four years in the county. Therefore we decided to investigate if a significant accumulation had occurred.
  
  
  METHODS
  Case records were examined to see whether the patients complied with the WHO criteria for possible, probable, or certain sporadic CJD. Poisson distribution with correction for age was used to compare the observed incidence with the expected incidence of 1 case/million/year.
  
  
  RESULTS
  Eight cases complied with the diagnostic criteria: two certain, three probable, two possible, and one familial. The incidence of certain and probable cases was 1.9 per million per year during the period, which does not constitute a significant increase (p = 0.18).
  
  
  CONCLUSIONS
  The result is consistent with the fact that all time or space clustering of CJD ever reported has proved ascribable to familial cases, and with the fact that case-control studies have never identified environmental risk factors for sporadic CJD.
authors.affiliation: Neurologisk afdeling, Centralsygehuset i Naestved.
authors.forename: B R
authors.initials: BR
authors.lastname: Christoffersen
authors.forename: J
authors.initials: J
authors.lastname: Jansen
mesh_terms: D000368:Aged; D007562:Creutzfeldt-Jakob Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies