Office of the Regional Executive for Biology - Central Region
7-22-2002
1. BSE: there are several new reports involving
individual case reports in Slovakia, Ukraine and the Czech Republic. Russia has
increasing concern over risk in that country. In a real economic twist to the
BSE scare, 2 companies in Japan have used the BSE issue in schemes to defraud
the government. Both companies tried to pass off foreign beef as domestic beef
thus causing their sales to plummet dramatically because of the BSE scare in
that country (Say what???). Sounds odd till you understand that the schemers
were banking on the domestic program payoffs and the ability to file for
bankruptcy protection.
2. vCJD: In the latest data available, the case incidence
rate shows a rapid increase: "Analysis of the incidence of vCJD onsets and
deaths from Jan 1994 to Dec 2001 shows evidence of an annual increase of around
20 percent for both onsets and deaths but, because of the considerable
uncertainties over the incubation period for vCJD, continuing surveillance will
be required to establish whether this trend is sustained in future years."
(The National CJD Surveillance Unit, 10th Annual Report, Tue 9 Jul 2002).
Because of this finding newspaper reports are latching onto a predicted increase
in vCJD cases (see report below). Additional information in this report
indicates genetic predisposition for development of vCJD, specifically
methionine homozygosity at codon 129 for the prion protein gene.
3. CJD and CWD??: I've included at the bottom a rather
lengthy newspaper report speculating on a cluster of Wisconsin CJD cases and
their possible relationship to CWD. CWD is THE headline wildlife news in the US
right now and speculation on its relationship to human disease continues in the
absence of good data on the issue. As you all will remember, similar speculation
on CJD and CWD followed the death of a 63 year old in Colorado recently. Some
folks are really paying attention to the possibility and the recent cases in
unusually young (for sporadic CJD) have only added fuel to the fire. If you
thought the recent poll showing 36% of Wisconsin deer
hunters would not participate in this fall's hunt was high,
wait till the effects of this report are disseminated. A new test (an ELISA)
being used in Europe for BSE and scrapie is undergoing trials at CSU to see if
it works for CWD. If validated this will greatly increase the speed of testing
surveillance tissues.
4. West Nile: WNV continues its march westward. In the last
couple of weeks first cases for 2002 have been reported in birds in Oklahoma,
Nebraska, Wisconsin and parts of Canada, and a horse in eastern North Dakota. In
addition, the first cases of WNV in humans for 2002 have been reported, all 7 in
Louisiana (see report below). Ages have been widely varying including teenage,
middle age and older. The number of cases and age distribution have created
significant concern. WNV is an avian virus with humans and horses as aberrant
dead-end hosts. Because migratory birds carry the virus, the disease is expected
to eventually envelope the entire country. WNV has also been reported now in
Ontario, Manitoba, and Quebec. Furthest west cases are Oklahoma/Texas, and
horses in North Dakota/Texas.
5. FMD: Scientific review and recommendations from the Royal
Society on Britain's handling of the FMD outbreak recommend changes in policy.
Vaccination would be the front line defense rather than wholesale slaughter of
millions of animals. You all might remember back to when this was a hot issue.
In most countries, if you are vaccinating against a disease that is considered
prima facie evidence that your country is not free of the disease. Thus there
has been intense pressure to eradicate by slaughter rather than through use of
vaccines. I think people are starting to recognize the global nature of FMD and
reexamining policies that result in tens of millions of animals killed. Even
just economically that is hard to justify. The second issue, though, may be
tougher to overcome - people's concern over eating FMD vaccinated animals (see
report below); never mind the fact that we already consume animals with lots of
vaccinations.
Thomas J. Roffe, PhD, DVM
USGS-BRD
Northern Rocky Mountain Science Center
FWP Bldg, 1400 S. 19th Ave.
Bozeman, MT 59718-5496
T: 406-994-5789
F: 406-994-4090
Cell: 406-539-4955
Supporting
Documents:
Date: Thu 11 Jul 2002
From: M. Cosgriff <mcosgriff@hotmail.com>
BBC News Online, Wed 10 Jul 2002 [edited]
<http://news.bbc.co.uk/hi/english/health/newsid_2120000/2120005.stm>
CJD cases "will increase"
Cases of variant Creutzfeldt-Jakob Disease, the human form
of mad cow disease, are set to increase by about 20 percent each year, experts
have predicted. But scientists at the National CJD Surveillance Unit in
Edinburgh stress numbers will still be very small. In their latest report (see
above), they said the "north-south divide", where the incidence is
higher in Scotland and northern England, will continue. The report predicted
there would be 32 deaths from vCJD, the human form of bovine spongiform
encephalopathy (BSE), this year.
The report said: "The upward trend in vCJD cases
continues to be statistically significant with an increase of 21 percent per
year for onsets and 23 percent per year for deaths. "The incidence of
vCJD across the UK continues to show a north-south divide, with a higher
incidence being maintained in the north of the UK." But scientists stress
the number of cases is small, and say the only "statistically significant
cluster" of vCJD cases occurred in Leicestershire. There, health
officials suggested meat preparation techniques used by local butchers in the
1980s could have led to cross-contamination of muscle meat with brain tissue.
But Professor Peter Smith, chairman of SEAC, the Spongiform
Encephalopathy Advisory Committee, told BBC News Online: "They are the
best estimates at the rate at which cases have been going up. But there is
quite a lot of uncertainty." Professor Smith added: "When vCJD was
first described, people felt that, because so many people could potentially
have eaten infected meat, that there could have been an epidemic of tens of
thousands. But as time has gone on, that has looked far less likely."
Date: Wed 17 Jul 2002
From: ProMED-mail <promed@promedmail.org>
Source: CNN online, Associated
Press report, Wed 17 Jul 2002 [edited]
<http://www.cnn.com/2002/HEALTH/conditions/07/17/west.nile.worries.ap/index.htm>
Louisiana: Human Case Number Rises to
Seven in Year 2002
NEW ORLEANS: Health officials are keeping a close eye on the
incidence of West Nile virus in Louisiana after 4 new cases were confirmed
this week, bringing the number to 7 this year. The federal Centers for Disease
Control and Prevention in Atlanta confirmed this week that a 34-year-old woman
and 3 men, ages 17, 62 and 76, had the mosquito-borne virus infection.
Last week, state health officials reported that 3
people, ages 53, 62 and 78, had the disease. The 78-year-old man was the
nation's first human found to have the disease this year.
Louisiana has not set any West Nile records, a 1999 outbreak
killed 7 people and sent 62 others to hospitals in New York, but Louisiana's
epidemiologist, Dr. Raoult Ratard, is concerned. "In 2001, no county in
the United States had more than 3 cases," Ratard said. "We are
getting up into fairly concentrated numbers. And of course it's early in the
season. So, the news is not that good."
West Nile virus has killed 18 people along the East
Coast since it was first detected in 1999. Last summer was the most severe,
with 66 human infections and 9 deaths nationwide.
Date: 18 Jul 2002
From: ProMED-mail <promed@promedmail.org>
Source: The Times, 17 Jul 2002 [edited]
<http://www.timesonline.co.uk/section/0,,172,00.html>
Consumers "must be persuaded that
vaccinated beef is safe"
A campaign to promote the safety of meat and milk from
animals vaccinated against foot-and-mouth disease was recommended yesterday as
a vital weapon to combat any future outbreak. The country's leading scientific
establishment, the Royal Society, insists that consumers must be won over if
the Government is to adopt a vaccination strategy. As The Times revealed last
month, the scientific inquiry backs the use of "ring" vaccination as
"major tool of first resort" to prevent any future outbreak becoming
an epidemic.
Unlike the Dutch experience last year, when vaccinated
animals were subsequently slaughtered and banned from human consumption, the
inquiry team advocates "vaccinate to live" with animals going
normally into the food chain. It is demanding a change of rules throughout the
European Union by the end of next year.
Sir Brian Follett, chairman of the inquiry, said that the
Food Standards Agency had already advised that there were no risks to human
health about eating products from vaccinated animals. He added: "I don't
know if society can face the alternative." (He was clearly referring to
the mass slaughter last year of more than 10 million farm animals.) Ian
McConnell, director of research at the Department of Clinical Veterinary
Medicine at Cambridge University, said that we already consume products from
animals vaccinated against 33 other diseases.
Consumer resistance was one of the main reasons for the
Government rejecting a vaccination programme last year. Supermarkets were
willing to stock vaccinated food but feared labelled products could be left
unsold.
Sir Brian said such a controversial debate should not take
place at the height of an epidemic. Contingency plans for a future outbreak of
livestock diseases should be debated in public and agreed by all interested
groups including consumers. An emergency drill should be rehearsed each year.
The inquiry also criticised the slaughter of animals within
a mile of an infected farm. This so-called "contiguous cull" was
recommended by scientists who had drawn up worst-case scenarios and forecasts
for the disease. David Black, a vet in private practice in Cumbria and a
member of the inquiry, said: "We still don't know how 80 percent of farms
became infected. The contiguous cull was an attempt to identify infected
animals but it was a blunt instrument."
The 400 000-pounds inquiry report concludes, however:
"For the foreseeable future there is no alternative, when an outbreak
occurs, to the rapid culling of diseased animals, and all those that are ...
likely to have been
infected by them." Sir Brian explained that the inquiry
had favoured emergency vaccination because mass culling was ineffective.
"Five times in 80 years we have not been able to contain this disease
with these methods. So we think, in most cases, we should use
vaccination."
The inquiry also accepted that the United Kingdom should
seek to remain free of the disease without routine vaccination. Within 10 to
15 years, however, a policy of routine vaccination may be possible. Diagnostic
tests will first have to be developed to distinguish whether an animal is
vaccinated or infected. Ben Gill, president of the National Farmers' Union,
supported emergency vaccination as an option. "The threat of importing
disease is increasing. It is vital that the resources needed to protect our
animal populations and native crops and plants keep pace with that."
A new early-warning system to alert the country to the
potential threat of new animal and human diseases is proposed by the Royal
Society inquiry. Bluetongue is a disease of sheep and goats, never yet found
in Britain but present in North America, China, Spain, France, Italy and the
Balkans "and so might move into Britain." It is fatal in 70 percent
of cases. African horse sickness can also affect dogs. Like bluetongue, this
disease spreads by midge bites. Avian influenza or fowl plague, always fatal
to poultry, was last seen in Britain 10 years ago. In 1997 a lethal strain was
transmitted directly from chickens to humans in Hong Kong. All chickens there
were slaughtered, a move the report describes as "drastic but wise."
Emergency vaccination is used to control an outbreak.
Date: Sun 21 Jul 2002
From: PromED-mail <promed@promedmail.org>
Source: Milwaukee Journal Sentinel, Sat 20 Jul 2002 [edited]
<http://www.jsonline.com/news/state/jul02/60546.asp>
Did wild game feasts lead to fatal
brain disorders?
Wild game feasts were a fall ritual that drew outdoorsmen to
a family cabin overlooking the Brule River in Wisconsin. The father of the
present owner died of Creutzfeldt-Jakob disease (CJD) and 2 other participants
also died from rare brain disorders. Now, years later, the legacy of those
hearty spreads of the late 1980s and early '90s is a medical mystery linking
these 3 diners.
One by one, the 3 have died from rare brain diseases,
leaving their families and health officials wondering whether their deaths
were an eerie coincidence or evidence that the deer and elk brain disorder
known as chronic wasting disease has crossed the threshold from animals to
people. Either way, their tale is one more warning sign on a cautionary trail
cutting through the heart of one of Wisconsin's most popular and revered
traditions: deer hunting.
Of the 3 deceased, 2 died of CJD, an always-fatal brain
ailment that occurs in only one in a million people. The third was believed to
have died of Pick's disease, a somewhat more common neurological disorder that
can be diagnosed in error when the true culprit is CJD.
Over the years, as many as 100 men may have taken part
in the wild game feeds at the Brule River cabin. The odds are strongly against
2 men dying of CJD, according to Dennis Maki, a professor of medicine and an
infectious disease expert at the University of Wisconsin-Madison; 3 would
increase those odds dramatically."It's very suspicious," he said.
The families of 3 men were devastated and baffled by
their deaths, 2 of which occurred in 1993 and the third in 1999; all before
chronic wasting disease was known to exist in Wisconsin's deer herd.
Raising more suspicion, however, is the fact that some of
the meat served at the wild game feasts was elk and deer from Western states,
including Colorado, where chronic wasting disease has been endemic for
decades. Presented last week with specifics of the cases, state public health
officials expressed concern. "We've immediately decided to proceed with
an investigation," said Jeffrey Davis, chief medical officer and state
epidemiologist for communicable diseases at the Wisconsin Division of Public
Health. He said the state will request death certificates and clinical and
laboratory records for the 3 men.
So far, there has not been a documented case of a
person contracting chronic wasting disease, but a handful of suspicious cases
have surfaced in Wisconsin and around the country, all involving venison
eaters who have contracted CJD, a deadly neurological disorder closely related
to mad cow disease. One of those cases involved a Minneapolis resident who
died of CJD in 1996 at the age of 41. He occasionally ate venison from
Wisconsin, including deer killed in Barron County. There have also been
several documented cases of CJD among people who cooked and ate brains from
squirrels and wild goats.
The human version of mad cow disease, known as new variant
CJD has killed more than 130 people in Europe and is believed to be caused by
eating contaminated beef. Scientists who watched mad cow disease jump from
animals to humans are now deeply concerned that chronic wasting disease will
make the same leap, if it hasn't already happened. "We're actively
looking for human beings who have acquired chronic wasting disease," said
G. Richard Olds, chairman and Linda and John Mellowes Professor of Medicine at
the Medical College of Wisconsin.
Chronic wasting disease, mad cow disease and CJD are
so-called transmissible spongiform encephalopathies and are believed to be
caused by prions. Prions are mutant proteins that get normal proteins to mimic
their distorted shape, resulting in a buildup of spongelike holes in the
brain. One reason prions are so feared is that they are highly resistant to
heat and other sanitizing methods. In addition, prions may silently incubate
for years or even decades in a person before producing symptoms of disease.
If chronic wasting disease prions were going to infect
people, the men who gathered for the feasts at the Brule River cabin in
northwestern Wisconsin were as likely candidates as any. Several of the men
were prolific hunters, bagging hoofed game in Wisconsin, the western United
States, Mexico, and Canada.
There may be reasons to question the diagnosis in the
case of the Pick's disease patient. It is "highly unusual" for a
Pick's patient to die within a year of the onset of symptoms, Grafman said.
The vast majority of patients die within 2 to 10 years, whereas the patient in
question died slightly less than a year after he first displayed symptoms It's
also unusual for someone to get Pick's after age 60 and this patient died at
age 66. More important, the gold standard for diagnosing Pick's disease is to
do an autopsy and a molecular analysis of brain tissue. However, according to
a certificate of death obtained from the state of Nevada, where the third
patient died after being taken to a clinic in Reno for treatment, no autopsy
was performed.
Maki said he believes that if chronic wasting disease
spreads among Wisconsin's deer herd, it's only a matter of time before the
disease spreads to people."We eventually will see cases (in
humans)," he said. However, he predicted the number of cases is likely to
remain small and the risk low.
In 2000, federal government researchers at the Rocky
Mountain Laboratories in Hamilton, Montana, analyzed prions from deer infected
with chronic wasting disease. The analysis showed a substantial molecular
barrier that helped prevent chronic wasting prions from converting normal
human protein to the mutant form. Despite the barrier, deer prions ultimately
were able to convert human protein to the mutant form. They did so with about
the same level of efficiency as mad cow prions.
Maki and others point to a growing body of evidence
linking the consumption of deer or other wild game with CJD. In 1984,
neurologists at Baylor College of Medicine investigated 4 suspicious deaths
involving unrelated patients, all with a history of eating the brains of wild
animals. All the patients eventually died, and CJD was the suspected cause.
"Our patients ate many brains from many wild animals over the course of
many years and therefore could have come in contact with infected
material," the researchers wrote.
In 1986, a study involving 26 CJD patients by researchers at
Temple University and the National Institutes of Health found that exposure to
deer through a hobby such as hunting resulted in up to a 9-fold increased risk
for CJD.
A 1997 study in the journal Lancet linked 5 unrelated CJD
patients from different towns in rural Kentucky to a history of eating
squirrel brains. "Culinary preparations include scrambling the brains
with eggs or putting them in a meat and vegetable stew referred to as
'burgoo,' " the researchers wrote.
In October 2001, a study in the journal Archives of
Neurology reported on the cases of 3 people who contracted CJD and who had
been deer hunters or had regularly eaten venison. The 3 individuals, who were
from Maine, Oklahoma, and Utah, all were under the age of 30 and came down
with the disease between 1997 and 2000. The vast majority of CJD patients get
the disease in their 60s and 70s. The researchers, some from the U.S. Centers
for Disease Control and Prevention, concluded that although circumstances
suggested a connection with chronic wasting disease, they could find no
"causal link." Now, the cases of
the 3 Wisconsin men raise some of the same questions. Fred Bannister, a
small-town doctor who knew all 3 men and took part in the wild game feeds,
said a thorough investigation of the case is needed.
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