Towards an age-dependent transmission model of acquired and sporadic Creutzfeldt-Jakob disease.

Introduction: Sporadic Creutzfeldt-Jakob disease (sCJD) might be transmitted by surgery. The purpose of this study was to investigate potential susceptibility to sCJD from surgery at juvenile age and in early adulthood.

Methods: From Danish and Swedish national registries we identified 167 definite and probable sCJD cases with onset from 1987 through 2003, and 835 age-, sex- and residence-matched controls along with their surgical histories. Main, anatomically or etiologically classified surgical procedures followed by a ≥20-year lag were analyzed using logistic regression, and stratified by age at first-registered surgical discharge.

Results: The risk of having a diagnosis of CJD depended strongly on age at first surgery with odds ratio (OR) of 12.80 (95% CI 2.56-64.0) in patients <30 years, 3.04 (95% 1.26-7.33) in 30-39 years, and 1.75 (95% CI 0.89-3.45) in ≥40 years, for anatomically classified surgical procedures. Similar figures were obtained for etiologically classified surgical procedures.

Conclusions: Risk of surgical-acquired sCJD depends on age at exposure; this pattern is similar to age-specific profiles reported for CJD accidentally transmitted by human pituitary-derived growth hormone and susceptibility curves for variant CJD estimated after adjustment for dietary exposure to bovine spongiform encephalopathy. There might be an age-at-exposure-related susceptibility to acquire all CJD forms, including sCJD from routine surgery.