From: TSS ()
Subject: CWD study needs more participants
Date: December 15, 2005 at 7:12 pm PST
CWD study needs more participants
By ANDREW BROWN, Dispatch Staff Writer
Ralph Garruto, a professor of biomedical anthropology at Binghamton, is leading a team of researchers conducting a study of the people who ate meat from deer infected with CWD at a sportsmen's feast in Verona earlier this year.
"It's become a real issue in the U.S.," Garruto said of CWD, a neurological disease found in deer and elk. "Why this particular study is so critically important is the fact that never before have we had a situation where we've had an animal that has tested positive for chronic wasting disease, and where we have had a fairly large group of individuals who may have butchered, or cooked, or consumed that meat, and we know who those individuals are."
Chronic wasting disease is a type of prion disease, or transmissible spongiform encephalopathy. It's caused by a mutation of the prion protein, which changes after infection into a shape Garruto described as being similar to a piece of leather folded over multiple times into a tight ball.
Although CWD is specific to deer and elk, prion diseases are found in many other animals. The most well-known form of the disease is mad cow disease, which has been found in cattle all over the world. The human form is known as Creutzfeldt-Jakob Disease, and there is also a form that infects sheep called scrapie.
At the Verona Fire Department's annual Sportsmen's Feast on March 13, an estimated 250 to 350 people ate venison from a deer that later was found to be infected with CWD.
"Based on the menu that was served I think it's safe to assume everybody who attended that function consumed the meat, because they served venison in virtually every dish that was offered on the menu," said Ken Fanelli, the Oneida County Health Department's public information officer.
What Garruto wants to find out is whether or not those people could have contracted a prion disease, such as Creutzfeldt-Jakob, from eating venison at the feast. Oneida County health officials told the people who ate the contaminated meat what is generally accepted in the scientific community about the issue: There is very little reason to worry.
"CWD has been around for 25 years in many Western states and there has never been anything linking it to a human illness," Fanelli said.
Garruto, however, believes several recent research studies might indicate otherwise. The most recent, a study published earlier this year in the Journal of Virology, found that chronic wasting disease could be transmitted to squirrel monkeys.
"All these other scientific studies are not directly providing evidence that humans are at risk, but they are building a lot of important circumstantial evidence that could provide the kind of scientific evidence that we need to establish a risk to humans," Garruto said of the recent studies on prion diseases.
Part of the reason many people believe humans are not at risk of catching CWD from deer is that prion diseases do not always jump what is known as the "species barrier." In other words, although it is generally believed that deer can give deer a prion disease, it is unknown whether deer can give people that prion disease.
For humans, that disease is Creutzfeldt-Jakob Disease, which, according to the World Health Organization, is always fatal. A neurodegenerative disease with no known cure, CJD is typically marked by several neurological symptoms, including depression, unsteadiness, difficulty walking and breathing and sometimes a schizophrenia-like psychosis.
Since so many of the disease's symptoms are related to the brain and spinal cord, Garruto's study will focus on these areas of the study's subjects. At the beginning, each subject must fill out a questionnaire that will indicate any neurological problems they had before attending the feast, and will describe how much contact they had with the infected deer that was served. They are also given a neurological examination at the beginning and then six years later at the end of the study.
For the next six years, Garruto and the other researchers will monitor the subjects for any changes in their condition. Mainly a surveillance project, the study involves very little bodily contact, and requires the subjects simply to check in with Garruto on a regular basis. They can update him on any changes in their condition over the phone or through written correspondence.
Although six years may seem like a long time to wait for the results, Garruto said the span was chosen because prion diseases often take at least five years to develop.
Garruto said only about 50 of the 300 people who attended the feast have contacted him about participating in the study. He said he needs at least two or three times that to get enough funding to keep the project going. Although ideally he would only study about 150 people, the potential impact of the project reaches far beyond that.
"This isn't just an issue about a number of people who attended that sportsmen's dinner, it has much, much broader implications," Garruto said.
Now found in 14 states and two Canadian provinces, CWD is what Garruto refers to as a "smoldering epidemic." Since two deer tested positive in Central New York in April, the state's Department of Environmental Conservation has not found any more deer with CWD, said DEC spokesperson Maureen Wren. The DEC has tested 7,165 deer statewide, including 1,791 in the CWD containment area that stretches from eastern Madison County to the Town of Trenton in Oneida County.
Regardless of the New York numbers, Garruto predicts CWD will soon spread to other Eastern states, where it could become a more severe threat.
"We are faced with a very significant issue, and we are not somewhere out in the Midwest with wide open spaces and few people," Garruto said. "We are now here on the East Coast of the United States, where you have some of the heaviest population density in the country."
The study could provide some answers to a lot of questions, and if nothing is found it could establish more definitively that there is no risk.
"That means that anyone who hunts, as well as those who don't hunt but who may eat venison or may butcher animals, it gives them some degree of confidence that they likely have no worries," said Garruto of the possibility that the study turns up nothing, a result he said he would be pleased with.
If Garruto and the other researchers do not get enough participants though, the study may not get off the ground. Fanelli said he believes one reason for the lack of interest in the study is because many people do not think there is a serious risk.
"As to why the response hasn't been greater, I think in part because the health department did a very effective job at that time getting the message out that there was no evidence linking chronic wasting disease in deer with any human illness," Fanelli said. "I think that contributes to the seeming lack of response to Dr. Garruto's study, that people feel, 'Well, if there is no public health risk or human health risk what's the point?' "
Fanelli thinks that's the wrong attitude to take towards the project though, considering its potential importance and the small amount of time involved.
"It doesn't involve any invasive testing or anything that's going to pose an additional risk to their health, so I really think it's a no brainer," Fanelli said. "I think people who were at that function should by all means take advantage of the study."
Although Garruto does not believe there is a very good chance that the study will turn anything up, he thinks it is important to carry it out anyway.
Said Garruto: "We have an ethical responsibility to make sure that there is no health issue here."
* Anyone who attended the Sportsmen's Feast in Verona and would like to participate in the study should contact Ken Fanelli of the Oneida County Health Department at 798-5099. They are asking both men and women of all ages to participate.
©The Oneida Daily Dispatch 2005
>>>Although six years may seem like a long time to wait for the results, Garruto said the span was chosen because prion diseases often take at least five years to develop. <<<
UNLESS THIS STUDY GOES BEYOND 15 YEARS, it's meaningless. ...TSS