--- Kevin Tarr <[EMAIL PROTECTED]> wrote: [I wrote:] <snip> > >Here in Colorado and a few contiguous states there's > >been a problem with Chronic Wasting Disease, a TSE, > >in deer and elk; it was recently discovered in > >Wisconsin as well... >http://www.nwhc.usgs.gov/research/chronic_wasting/chronic_wasting.html
> That's weird. I went to the CWD website: > http://www.cwd-info.org/index.php/fuseaction/about.map > > and it had nothing for PA. I was sure some whitetail > deer, on a captive farm, were found with CWD. In PubMed, there was no entry for CWD AND (Penn OR PA); there were 2 2003 articles that reported no evidence of CWD in humans. The abstract of one: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12617536&dopt=Abstract "Creutzfeldt-Jakob disease (CJD) is a fatal neurologic disorder in humans. CJD is one of a group of conditions known as transmissible spongiform encephalopathies (TSEs), or prion diseases, that are believed to be caused by abnormally configured, host-encoded prion proteins that accumulate in the central nervous tissue. CJD has an annual incidence of approximately 1 case per million population in the United States and occurs in three forms: sporadic, genetically determined, and acquired by infection. In the latter form, the incubation period is measured typically in years. Recent evidence that prion infection can cross the species barrier between humans and cattle has raised increasing public health concerns about the possible transmission to humans of a TSE among deer and elk known as chronic wasting disease (CWD). During 1993-1999, three men who participated in wild game feasts in northern Wisconsin died of degenerative neurologic illnesses. This report documents the investigation of these deaths, which was initiated in August 2002 and which confirmed the death of only one person from CJD. Although no association between CWD and CJD was found, continued surveillance of both diseases remains important to assess the possible risk for CWD transmission to humans." (The other has no abstract, but is titled "Still no human cases of chronic wasting disease" from Mayo Clinic Letters.) > But I have a question about Mad Cow disease... > First was the cattle incubation period of 3-7 years. > Does that mean if the > animal is infected, it is not sick for at least > three years? Is it contagious before three years? The WHO site states "The disease has a long incubation period of four to five years, but ultimately is fatal for cattle within weeks to months of its onset." http://www.who.int/mediacentre/factsheets/fs113/en/ When the animal becomes obviously sick, it lives only for several weeks more; I couldn't find the direct answer to your question WRT human infection, but would certainly presume the brain and spinal cord tissue are infectious before the animal is clearly ill. However, the _amount_ of infected tissue that must be consumed to produce human disease is not yet known; there appears also to be a genetic susceptibility to becoming infected/developing vCJD. This 2001 article from the British Medical Journal gives some background for BSE, describes experiments of infectivity in mice, and discusses vCJD. http://www.findarticles.com/cf_0/m0999/7290_322/74089375/p1/article.jhtml?term=cjd > Second was the incubation period in humans. The > caller said 5 to 40 years > and it's 100% fatal. True, false, real facts? So far the incubation period is about 10 years, then symptoms begin & progress over 6+ months to death. The possibility of genetic resistance to BSE exists, such that the incubation period in these humans could be 20 or 40 years; however we _do_not_ have any evidence of this so far. This is a long 2001 CDC article: http://www.findarticles.com/cf_0/m0999/7290_322/74089375/p1/article.jhtml?term=cjd > The third, related to the long human incubation > period, was that it may be > causing Alzheimer disease. Somebody eating bad meat > 30 years ago gets diagnosed with Alzheimer today. Bob Z answered this already; someone may have confused the reported findings of brain amyloid plaques in a few vCJD patients with "evidence that it causes Alzheimer's" (since plaques in the brain do occur in Alzheimer's). > Fourth and last I heard from another source. When it > was first discovered > in England they did a survey of those affected, or > the families of those > who died, and found 24 of the first 28 ate cow > brains as a meal. <insert > conspiracy music> That study was hushed up because > the public wouldn't take > it as seriously, seeing no risk by just eating > regular meat. Nerve tissue did get into certain processed meats (sausage, bologna, etc.) because of the mechanical extraction process, but I didn't see anything about vCJD occurring only in Eaters-of-Brayyyyyns... :P Other tissues known to be infective to experimental animals include part of the small intestine (the ileum; I think animal intestine is sold as "tripe") and the retina (mmm, scoop up those eyeballs!). Debbi Doesn't That Make You Hungry? Maru ;) __________________________________ Do you Yahoo!? Free Pop-Up Blocker - Get it now http://companion.yahoo.com/ _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
