Reasonable Rascal
03-29-02, 17:01
Population-based Autopsy Findings Confirm Variant CJD Is A New Disease
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A systematic review of Welsh death records and autopsy samples confirms the description of variant Creutzfeldt-Jakob disease [abbreviated as vCJD or CJD (new var.) in ProMED-mail] as a new disease entity, rather than a result of better case ascertainment.
Dr. C. E. M. Hillier, of the University Hospital of Wales in Cardiff, and associates, obtained death certificate data from the Office of National Statistics for deaths of individuals aged 15 to 45 between 1985 and 1995, to search for cases of vCJD that might not have been recognized before the first
cases were reported in 1996. They compiled a list of International Classification of Diseases version 9 (ICD-9)codes that might be mistaken for vCJD, which they called "non-specific fatal disorders compatible with vCJD." For cases that fit within this classification, the group obtained postmortem
brain material whenever possible, for examination by immunocytochemical staining for prion protein. Their findings appear in the Journal of Neurology, Neurosurgery, and Psychiatry:
Hillier CE, Salmon RL, Neal JW, Hilton DA. Possible under-ascertainment of variant Creutzfeldt-Jakob disease: a systematic study. J Neurol Neurosurg Psychiatry 2002;72:304-309.
<http://jnnp.bmjjournals.com/cgi/content/full/72/3/304>
Of 12 091 deaths, excluding external injury and poisoning, 3322 fit within the authors' classification scheme. The authors excluded deaths where the maximum duration of illness from onset of symptoms exceeded 36 months, given that the first published vCJD cases had a maximum duration of 35 months. They
also excluded illnesses for which clinical, laboratory, or pathological evidence for the disease existed. None of the more than 250 brain tissue specimens examined exhibited the pattern of prion protein immunoreactivity
associated with vCJD, even though nearly half exhibited some immuno-reactivity. In the few cases in which vacuolation was observed, it appeared to result from brain edema, recent lack of oxygen, or procedural artifacts.
No spongiform changes or pathological plaques were observed.
"No case met the CJD Surveillance Unit criteria for even possible vCJD," the authors write.
Based on these data, the upper 95% confidence interval for the incidence of death from vCJD would be 0.12 per million/year, which is markedly different from the actual mortality rate for 1995 to 2000 of 0.29 per million/year. This indicates "an increase in incidence in the past 5 years which is
unlikely to be due to chance alone," the investigators write. "It suggests that vCJD is indeed a new disease."
--
George A. Robertson, PhD
WYETH VACCINES
PO Box 304
Marietta, PA 17547-0304
<RobertG3@wyeth.com>
[These data provide further confirmation of the coincidence of the outbreak of vCJD in humans and the marketing of meat for human consumption derived from BSE-affected cattle. Nonetheless, the mode of transmission from cattle to humans is still unclear, since the evidence for an association between meat consumption and disease in humans remains circumstantial. - Mod.CP]
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Copied under the fair use for education doctrine from the Harvard ProMed List.
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A systematic review of Welsh death records and autopsy samples confirms the description of variant Creutzfeldt-Jakob disease [abbreviated as vCJD or CJD (new var.) in ProMED-mail] as a new disease entity, rather than a result of better case ascertainment.
Dr. C. E. M. Hillier, of the University Hospital of Wales in Cardiff, and associates, obtained death certificate data from the Office of National Statistics for deaths of individuals aged 15 to 45 between 1985 and 1995, to search for cases of vCJD that might not have been recognized before the first
cases were reported in 1996. They compiled a list of International Classification of Diseases version 9 (ICD-9)codes that might be mistaken for vCJD, which they called "non-specific fatal disorders compatible with vCJD." For cases that fit within this classification, the group obtained postmortem
brain material whenever possible, for examination by immunocytochemical staining for prion protein. Their findings appear in the Journal of Neurology, Neurosurgery, and Psychiatry:
Hillier CE, Salmon RL, Neal JW, Hilton DA. Possible under-ascertainment of variant Creutzfeldt-Jakob disease: a systematic study. J Neurol Neurosurg Psychiatry 2002;72:304-309.
<http://jnnp.bmjjournals.com/cgi/content/full/72/3/304>
Of 12 091 deaths, excluding external injury and poisoning, 3322 fit within the authors' classification scheme. The authors excluded deaths where the maximum duration of illness from onset of symptoms exceeded 36 months, given that the first published vCJD cases had a maximum duration of 35 months. They
also excluded illnesses for which clinical, laboratory, or pathological evidence for the disease existed. None of the more than 250 brain tissue specimens examined exhibited the pattern of prion protein immunoreactivity
associated with vCJD, even though nearly half exhibited some immuno-reactivity. In the few cases in which vacuolation was observed, it appeared to result from brain edema, recent lack of oxygen, or procedural artifacts.
No spongiform changes or pathological plaques were observed.
"No case met the CJD Surveillance Unit criteria for even possible vCJD," the authors write.
Based on these data, the upper 95% confidence interval for the incidence of death from vCJD would be 0.12 per million/year, which is markedly different from the actual mortality rate for 1995 to 2000 of 0.29 per million/year. This indicates "an increase in incidence in the past 5 years which is
unlikely to be due to chance alone," the investigators write. "It suggests that vCJD is indeed a new disease."
--
George A. Robertson, PhD
WYETH VACCINES
PO Box 304
Marietta, PA 17547-0304
<RobertG3@wyeth.com>
[These data provide further confirmation of the coincidence of the outbreak of vCJD in humans and the marketing of meat for human consumption derived from BSE-affected cattle. Nonetheless, the mode of transmission from cattle to humans is still unclear, since the evidence for an association between meat consumption and disease in humans remains circumstantial. - Mod.CP]
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Copied under the fair use for education doctrine from the Harvard ProMed List.