vCJD continues to baffle scientists; teenagers disproportionately susceptible
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 BoŽlle and his colleagues from Assistance Publique HŰpitaux de Paris and Universitť 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 BoŽlle. "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 BoŽlle, 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
Please quote the journal in any stories you write, and link to the article if you are writing for the web.###
For further information about this research, please contact Dr Pierre-Yves BoŽlle by email at firstname.lastname@example.org 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 email@example.com or by phone on 44-207-631-9931
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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