vCJD continues to baffle scientists; teenagers disproportionately susceptible

Main Category: CJD / vCJD / Mad Cow Disease
Article Date: 10 Aug 2004 - 0:00 PDT


That young people tend to eat more beef products is not enough to explain the strikingly high proportion of new-variant Creutzfeldt-Jacob disease cases among children and adolescents. An article published this week in BMC Infectious Diseases, shows that young people must also be more susceptible to vCJD infection because of their age.

New detailed estimates of the UK population's dietary exposure to bovine material according to age have recently become available. Pierre-Yves Boëlle and his colleagues from Assistance Publique Hôpitaux de Paris and Université Joseph Fourier, Grenoble plugged this information into a mathematical model that predicts the age distribution of vCJD cases.

"We found that exposure alone could not explain the young age of vCJD cases as seen in the UK," said Boëlle. "An additional effect of age-dependent susceptibility was required to fully account for the age of the vCJD cases."

If the researchers considered exposure to beef products as the only risk factor, the predicted age distribution did not fit well with the actual age distribution of the 137 reported cases. This model predicted that 48% of those with vCJD are over 40, whereas in reality only 10% of people affected by the disease fall into this age group.

The predicted distribution of cases was much closer to the actual age distribution if the researchers considered both exposure and an age-dependent susceptibility to the disease as risk factors. The susceptibility to vCJD was predicted to increase during childhood, peak during adolescence and decrease sharply afterwards.

With this model, 12% of cases were estimated to be in people over 40, and the predicted ages of people with the disease showed good agreement with the actual distribution of cases.

The researchers suggest that, "one possible explanation for the difference in susceptibility could be that the permeability of the intestinal barrier changes with age, as the number of Peyer's patches decrease." However, they stress that further research is needed, as this is a very unusual characteristic of an infectious disease.

This press release is based on the following article:

Epidemiological evidence of a higher susceptibility to vCJD in the young
PY Boëlle, JY Cesbron and AJ Valleron
BMC Infectious Diseases, 2004. 4:26
To be published Tuesday 10 August, 2004

Upon publication, this article will be available free of charge according to BMC Infectious Diseases'
Open Access policy at http://www.biomedcentral.com/1471-2334/4/26

For further information about this research, please contact Dr Pierre-Yves Boëlle by email at boelle@u444.jussieu.fr or by phone on: 33-149-283-226

Alternatively, or for more information about the journal or Open Access publishing, contact Gemma Bradley by email at press@biomedcentral.com or by phone on 44-207-631-9931

BMC Infectious Diseases (http://www.biomedcentral.com/bmcinfectdis) is published by BioMed Central (http://www.biomedcentral.com), an independent online publishing house committed to providing Open Access to peer-reviewed biological and medical research. This commitment is based on the view that immediate free access to research and the ability to freely archive and reuse published information is essential to the rapid and efficient communication of science. BioMed Central currently publishes over 100 journals across biology and medicine. In addition to open-access original research, BioMed Central also publishes reviews, commentaries and other non-original-research content. Depending on the policies of the individual journal, this content may be open access or provided only to subscribers.

Contact: Gemma Bradley
press@biomedcentral.com
44-207-631-9931
BioMed Central

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