Surveillance for progressive intellectual and neurological deterioration in the Canadian paediatric population.

OBJECTIVES

To conduct active surveillance of the Canadian paediatric population for children who have a progressive intellectual and neurological deterioration to detect the occurrence of cases of Creutzfeldt-Jakob disease or variant Creutzfeldt-Jakob disease.

CASE DEFINITION: Any child who is less than or equal to 18 years of age, who had a progressive loss of already attained intellectual/developmental abilities and development of abnormal neurological signs of greater than three months duration was eligible for inclusion.

DURATION: July 1999 to July 2001.

METHOD: Enhanced active surveillance system for progressive intellectual and neurological deterioration was implemented to detect, prospectively, among the Canadian paediatric population. Each month, all paediatricians and paediatric neurologists in Canada were mailed a reporting form. All reported cases were reviewed by the principal investigator who classified the cases into one of four predetermined categories. Cases where there was evidence of neurological and intellectual regression without known cause were reviewed by a panel. Reported cases were reviewed for the possibility of classic or variant Creutzfeldt-Jakob disease.

RESULTS

Over 2200 physicians took part in this program. There was more than an 80% monthly return rate of the initial report form. Ninety-nine possible cases of progressive neurological and intellectual deterioration were reported. Sixty cases were classified as having a progressive neurological syndrome associated with intellectual deterioration. Fourteen cases were duplicates. One case of Creutzfeldt-Jacob disorder was found but no cases of the variant form of Creutzfeldt-Jacob disorder. Fifteen cases were felt not to meet the above-mentioned entry criteria.