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From: TSS (216-119-139-126.ipset19.wt.net)
In Reply to: Re: CWD SAMPLING TEXAS (but NOT in the obvious place, the NM, TEXAS border) posted by Ken Waldrup, DVM, PhD on December 15, 2003 at 3:43 pm:
HEllo Dr. Waldrup, thank you for your comments and time to come to this board. Ken Waldrup, DVM, PhD states; > it is painfully obvious that you do not know or understand the natural distribution of mule deer out there or the rights of the land owners in this state... TSS states; I am concerned about all deer/elk not just mule deer, and the rights of Ken Waldrup, DVM, PhD states; > Deer and elk from the Guadalupe Peak National Park cannot be collected with federal permission. TSS states; I do not understand this? so there is no recourse of action even if Ken Waldrup, DVM, PhD states; > I am concerned about your insinuation that CWD is a human health risk. We are at a stand-off - you have no proof that it is and I have no definitive proof that it isn't. However I would say that the inferred evidence from Colorado, Wyoming and Wisconsin suggests that CWD is not a human health concern (i.e. no evidence of an increased incidence of human brain disorders within the CWD "endemic" areas of these states)... TSS states; indeed i am concerned as well with your insinuation about CWD not The EMBO Journal, Vol. 19, No. 17 pp. 4425-4430, 2000 Evidence of a molecular barrier limiting G.J. Raymond1, A. Bossers2, L.D. Raymond1, K.I. O?Rourke3, 1NIAID/NIH Rocky Mountain Laboratories, Hamilton, MT 59840, snip... Clearly, it is premature to draw firm conclusions about CWD snip... http://www.emboj.org/current.shtml Ken Waldrup, DVM, PhD states; > However I would say that the inferred evidence from Colorado, Wyoming and Wisconsin suggests that CWD is not a human health concern (i.e. no evidence of an increased incidence of human brain disorders within the CWD "endemic" areas of these states)... TSS states; I disagree with this on several fronts as well. for one thing there is The active surveillance study of 1996, however, only looked at cases in which physicians attributed the deaths to CJD. Misdiagnosed patients or patients who never saw a neurologist were not tabulated thus CJD may be grossly underreported. Many neurological ailments share symptoms, especially early on. According to various studies, autopsies have found that CJD is misdiagnosed as other ills, such as dementia or Alzheimer's disease, 5 to 13 percent of the time. The CDC finds that around 50,000 Americans die from Alzheimer's each year 228 CHAPTER 14 (about 4 million have the disease, according to the Alzheimer's Association). Therefore, one could argue that thousands of CJD cases are being missed. (On the flip side, CJD could be mistakenly diagnosed as Alzheimer's disease or dementia, but the number of CJD patients is so small that they wouldn't dramatically skew the statistics for other neurological ills.) In part to address the issue of misdiagnosis, CJD families have asked the CDC to place the disease on the national list of officially notifiable illnesses, which tends to include more contagious conditions such as AIDS, tuberculosis, hepatitis, and viral forms of encephalitis. Currently, only some states impose this requirement. CDC officials have discounted the utility of such an approach, arguing that it would duplicate the mortality data, which is more accurate than early diag- noses of CJD, anyway. Moreover, mandatory reporting of CJD cases does not necessarily guarantee the end to missed cases.8 One clue suggests that the passive system is undercounting CJD in the U.S.: racial difference. The number of black CJD victims is about 38 percent that of white victims. Rather than sporadic CJD being a one- in-a-million lottery, it's more like one-in-2.5-million for African- Americans. Access to medical care might be one reason. Schonberger recounted that the CDC had asked other countries with substantial black populations to submit CJD figures for comparison but found that the surveillance in those countries was inadequate. "We haven't been able to find any comparable literature on this issue, so it's still up in the air," Schonberger said. On the other hand, Alzheimer's disease is more common among black people than whites, with an estimated higher prevalence ranging from 14 percent to almost 100 percent, according to a February 2002 report by the Alzheimer's Association. Are some black CJD cases being misdiagnosed as Alzheimer's? Answering critics like Terry Singeltary, who feels that the U.S. under- counts CJD, Schonberger conceded that the current surveillance system has errors but stated that most of the errors will be confined to the older population. As Schonberger pointed out, no doctor would misdiagnose a 30-year-old CJD patient as having Alzheimer's. The average age of the first 100 variant CJD victims was 29; should the epidemiology of vCJD changeif older people start coming down with itthen there would be problems. "The adequacy of our overall CJD surveillance would be Laying Odds 229 greatly reduced should the proportion of older individuals affected by variant CJD substantially increase," Schonberger explained.9 To date, only brain autopsies can confirm CJD. To encourage the necessary neuropathological studies, in 1997 the CDC helped establish the National Prion Disease Pathology Surveillance Center at Case Western Reserve University, under the directorship of Pierluigi Gambetti. But the number of brains examined has fallen far short of the number of CJD cases in the U.S.: Gambetti's lab, which receives brains based on referrals from local physicians and families, looked at only 99 sporadic CJD cases in 2000 and 138 in 2001, when about 300 each year are expected. "I'm very unhappy with the numbers," Gambetti lamented. "European countries see 100 or 90 percent of all the cases suspected. We see 30 to 40 percent."10 Most families don't think about having an autopsy done (which can cost upward of $1,500 if the hospitals don't pick up the tab), and mem- bers of the support group CJD Voice have said they were too distraught to think of shipping a loved one's brain by Federal Express to Gambetti's lab. (For accurate analyses of brain tissue, the autopsy must be performed within 72 hours of death, assuming the body has been kept refrigerated.) Moreover, physicians often do not suggest an autopsy, perhaps because of liability fears should the postmortem reveal that the original diagnosis was wrong. Gambetti has been work- ing on establishing a network that would enable postmortems to be done near where the deceased person lived and without cost to the family. He is also working on advertising the existence of his surveil- lance center, via meetings and letters to neurologists, pathologists, and other specialists. Gambetti is also attempting to combat what he termed "hysteria" over the potential for infection that has pathologists irrationally shunning CJD cases while they willingly conduct arguably riskier AIDS autopsies. "In order to make people aware, you have to keep informing them over and over and over," he said. Money is the main reason why the U.S. lags behind Europe in terms of surveillance. To adequately survey the 290 U.S. million residents, "you need a lot of money," Robert Will explained. "There was a CJD meeting of families in America in which poor old Larry {Schonberger] got attacked fairly vigorously because there wasn't proper surveillance. You could only do proper surveillance if you have adequate resources. 230 CHAPTER 14 That's the bottom line. We're very fortunate in the U.K.; we have very generous resources for CJD surveillance." Moreover, the U.K. makes feline spongifbrm encephalopathy an offi- cially notifiable disease. Domestic cats proved to be good sentinel ani- mals because they dine on the meat not fit for human consumption the parts more likely to harbor prion infectivity. In the U.S., FSE isn't federally notifiable. And while the USDA says it has sent educational material to private veterinarians and works with vet schools,21 it's not clear just how many vets can spot FSE, which has never been reported in the U.S. Certainly, not many cat postmortems are done. The only active portion of the U.S. CJD surveillance system are the follow-up investigations conducted for victims of CJD under 55 years of age. It began in 1996, when young people in the U.K. started succumb- ing to variant CJD. Victims under 30 years of age especially arouse interest, because such cases could indicate an infection from the envi- ronment. Except for the variant CJD case in Florida, the CDC has clas- sified all of these more youthful cases of CJD as having either sporadic or familial origins. One such age cluster involved the three venison eaters that the CDC tried unsuccessfully to link to the deer-and-elk borne chronic wasting disease. A second grouping occurred in 2002 in a pair of Michigan men. The twoone 26 years old, the other 28 did not know each other but lived in neighboring counties in Michigan and went to the same hospi- tal for diagnosis.12 The CDC's investigation turned up nothing that suggested a new form of CJD had emerged. But the increased frequency of young CJD cases is disturbing. In the 18-year period between 1979 and 1996, the U.S. had 12 cases in patients under 30, and only one of them had the sporadic form of CJD. (The other cases resulted from heredity or from transmission via contami- nated growth hormone or dura mater grafts.13) Between 1997 and 2001, five people under 30 died of sporadic CJD: the three venison eaters and the two Michigan patients. That represents a substantial blip of five young cases in five years, as opposed to only one case in 18 years. Physicians at the University of Michigan Health System who examined the two Michigan men concluded: As a result of our findings, we feel that sporadic CJD may be more common than previously thought, that it may occur in younger indi- Laying Odds 231 viduals than currently perceived, and that some cases may go undiag- nosed due to insufficient testing. . . . We recommend that physicians everywhere begin to consider CJD in rapidly progressive neurological decline of unknown causes in people under 30 years of age, and that brain biopsy and autopsy with genetic and prion analysis be performed in all such cases.14 Pathologically, the recent bout of young casualties in the U.S. appears to be no different from CJD already seen in America. Yet theoretically it may have come from a new source of infection, based on an unex- pected result announced in late November 2002. John Collinge of the British Medical Research Council's Prion Unit found that not all trans- genic mice infected with BSE prions developed the neuropathological and molecular characteristics of variant CJD; some of the mice instead generated the molecular features of sporadic CJD. Therefore, some CJD cases classified as sporadic may have actually been caused by BSE prions, Collinge hypothesized.15 So far, the epidemiology of CJD in the U.K. does not bear out that suppositionthere has been no substantial uptick in sporadic CJD as would be expected if BSE could paint more than one pathological picture. But the preliminary study, taken at face value, could be seen as evidence that something infectious is happening in the cases of young, sporadic CJD victims in the U.S. Another mouse study, reported in March 2002, fueled concern that prion infections may be more common than previously thought.16 Stanley Prusiner's lab found that mice infected with mouse prions accu- mulated PrPSc in their skeletal muscles, mostly in those in the hind limbs. In some mice, each gram of muscle contained some 10 million infectious doseson par with that in the brain in other experiments involving intracerebral inoculation. To some CJD researchers, this find- ing suggested that muscle meat from cows might not be safe, after all, and that the measures taken in Europe to protect the food supply banning high-risk cow partsmay not be enough. Although this study may seem alarming, its implications are not as sweeping as they may appear. Only a minority of results in mouse stud- ies end up having a direct analog in humans. The skeletal muscle discov- ery warrants further examination, but it would be premature to alter food policies. Prions are different for each species, and accumulation of prions varies from species to species and from disease to disease. Furthermore, BSE cattle muscle has failed to sicken mice in bioassay 232 CHAPTER 14 work, suggesting that little or no infectious prions lurk there. What such findings truly reveal is that prion diseases are complicated and still mysterious, and trying to quantify the risks for human health is fraught with uncertainties...snip...284 pages...thanks Philip...TSS The Pathological Protein: Mad Cow, Chronic Wasting, and Other Deadly Prion Diseases, Philip Yam Philip Yam News Editor Scientific American www.sciam.com http://www.thepathologicalprotein.com/ CJD screening may miss thousands of cases By Steve Mitchell WASHINGTON, July 21 (UPI) -- The federal government's monitoring system Creutzfeldt-Jakob disease or CJD can be caused by eating beef Beginning in the late 1990s, more than 100 people contracted CJD in the No case of mad cow has ever been detected in U.S. cattle and the Centers The first symptoms of CJD typically include memory loss and difficulty Spontaneously-occurring or sporadic CJD is a rare disorder. Only about Clusters of CJD have been reported in various areas of the United States People who develop CJD from eating mad-cow-contaminated beef have been "Now people are beginning to realize that because something looks like Several studies, including Manuelidis', have found that autopsies reveal Experiences in England and Switzerland -- two countries that discovered Switzerland discovered last year its CJD rate was twice that of any The CDC says the annual rate of CJD in the United States is one case per Diagnosing CJD or Alzheimer's is difficult because no test exists that Unfortunately, although autopsies once were performed on approximately "If we don't do autopsies and we don't look at people's brains ... we At the same time autopsies have been declining, the number of deaths "Neurodegenerative disease and Alzheimer's disease have become a The autopsy studies that found undiagnosed CJD cases raise the question "What's the source of that?" Nelson asked. "Could it be the same source Nelson referred to an outbreak of a mad-cow-type disorder in minks in Andrew Monjan, chief of the neuropsychology of aging program at the "There's been no change in the number of CJD cases in the country and If more states made CJD a reportable illness, there would be more Singletary also said there have been increases in sporadic CJD in So far, the CDC has refused to impose a national requirement that Instead, the agency relies on other methods, including death Belay told UPI he discounted this possibility. It is unlikely to happen, Manuelidis disagreed. It can be quite difficult to determine accurately The U. Penn. researchers concluded: "These results show that in patients In addition, the NPDPSC sees less than half of all the CJD cases each Belay said the CDC follows up on all cases of CJD that occur in people The case of Carrie Mahan -- a Philadelphia woman who developed a brain Mahan's physician, Dr. Peter Crinos of the University of Pennsylvania Subsequent research, however, has shown the test used by the "There's no question that Carrie had a spongiform encephalopathy," Crinos told UPI until the CDC implements a better tracking system, a lot Copyright © 2001-2003 United Press International http://www.upi.com/view.cfm?StoryID=20030721-102924-4786r One reason for this was the _inaccuracy_ in coding of cases correctly certified as CJD Coding is carried out by staff who are not medically qualified and it is not surprising that coding errors occur in the processing of large numbers of certificates. In 1982, 12,000 certificates per week were processed at the office of population censuses and surveys bu 15 coders and 6 checkers (Alderson et al., 1983). The occurrence of both inter- and intra-observer coding errors has been described (Curb et al., 1983) and the _inaccuracies_ of BOTH certification and coding discovered in this study _support_ the introduction of a more accurate system of death certificates and a more detailed and specific coding system... snip... http://www.bseinquiry.gov.uk/files/mb/m26/tab01.pdf AS implied in the Inset 25 we must not _ASSUME_ that snip... http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf Ken Waldrup, DVM, PhD states; > and is dictated by the availability of funds. snip... > From my professional interactions with the Texas Parks and Wildlife Department, I can definitely say that they want to do a thorough and sound survey throughout the state, not willy-nilly "look here, look there". There are limitations of manpower, finances and, in some places, deer populations. I would congratulate TPWD for doing the best job with the limitations at hand... TSS states; I would concur here, and congradulate them as well. BUT, it is not Ken Waldrup, DVM, PhD states; > rather than trying to browbeat them when you obviously do not understand the ecology of West Texas. TSS states; I am not browbeating anyone, or no intention, just trying to keep again, thank you for your comments, they are very much appreciated. kind regards,
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