Pork plant worker says symptoms
started with charley horse
MINNEAPOLIS (AP) It started with a
charley horse for Susan Kruse.
She had worked at the Quality Pork
Processors plant in Austin for 15 years.
Then the 36-year-old started having
cramps in her legs, followed by muscle
stiffness, soreness and pain that left
her unable to work and dependent on a
walker to get around.
Kruse was among the first of 11
employees at the plant to be diagnosed
with a rare neurological disease called
CIPD, short for chronic inflammatory
Doctors have told her she may never
work again. Her disability insurance
payments recently ended, and she's now
living on Social Security.
``It started with a charley horse in
my calf that wouldn't go away,'' Kruse
told the Star Tribune in an interview at
her home Tuesday night. ``Then my hands
and feet got sore and cold and numb. I
had perfect health before.''
``She can't do a lot of the things
she used to,'' said her son, Travis
Kruse, a ninth-grader. ``Before, she
could lift heavy boxes and stuff, but
now she gets tired after she walks a
The plant owner, Kelly Wadding, said
Tuesday that investigators told him they
probably won't know ``for some time''
what caused the illnesses.
The Minnesota Department of Health,
which disclosed the illnesses Monday, is
leading the investigation, which is
expected to take months or longer.
Department staffers arrived in Austin on
Tuesday, while another team is
researching the autoimmune disease,
which normally strikes only two out of
every 100,000 people.
``We're trying to get a sense of
whether the incidence has changed in
recent years,'' State Epidemiologist
Ruth Lynfield said, adding that there
could be clusters of cases elsewhere in
the country that have not been
Officials were able to connect the 11
Austin cases because of a fortunate
confluence of events, Lynfield said.
Plant nurses were the first to recognize
that they were seeing an unusual number
of people with odd neurological
symptoms. They very quickly connected
with doctors at the Mayo Clinic in
Rochester who happen to be among the
nation's experts in CIDP, she said.
Autoimmune diseases occur when the
body's immune system attacks healthy
tissue because it can't tell the
difference between healthy tissue and
foreign invaders. In the case of CIPD,
it gradually damages the tissue sheath
surrounding nerves in arms, legs and the
Kruse went through another battery of
tests at Mayo on Tuesday. Every other
week, she spends five hours receiving an
intravenous drug that doctors hope will
ease her symptoms, which include muscle
weakness, pain and tingling. She had
been puzzled about the illness until
last week, when someone from the Health
Department called asking questions. Then
she ran into a co-worker at Mayo who had
the same illness.
But it wasn't until Monday's Health
Department news conference that she
realized the link to her job.
Kruse worked in the ``day kill
area,'' where she carved meat out of the
back of butchered pigs' heads with a
small knife. Her work area was next to
the place where compressed-air hoses
were used to blow out brain material
from pig skulls.
According to experts, the cause of
CIDP is unknown and could include any
number of factors, including infectious
microbes, toxins or something from the
pigs that triggers the body's immune
system to attack healthy tissue. It's
the chronic form of another disease,
Guillain-Barre syndrome, which develops
much more rapidly and has a number of
known triggers. It first received public
attention in 1976 when linked to the
swine flu vaccine. CIDP does not appear
to be spread by person-to-person
contact, Lynfield said.
Symptoms first emerged around the
same time the plant began using the
high-pressure air system. Some health
experts think exposure to blood and
pulverized tissue might have caused the
autoimmune response, and they
recommended that the plant shut the
compressed-air system down.
Kruse said she liked her job and is
sorry she can no longer do it.
``It's depressing,'' she said of her
increased weakness and decreased
mobility and of her uncertain future.
``I hope that my arms aren't so weak
that I can't at least get a desk job.''
Update presented on disease in pork plant workers
SEATTLE – More than a year after developing a unique neurological
disorder, the affected pork processing plant workers have improved,
but all have some continuing symptoms and many have ongoing mild
pain, according to a study released today that will be presented at
the American Academy of Neurology's 61st Annual Meeting in Seattle,
April 25 to May 2, 2009.
The workers developed symptoms such as walking difficulties,
weakness, numbness and tingling in the arms and legs, pain and
fatigue. All had worked in or near the area where compressed air was
used to extract pig brains. All plants have discontinued the
For the study, researchers reexamined 24 of the workers affected
at plants in Minnesota and Indiana. Of those, 17 were treated with
immune therapy such as steroids. Sixteen people improved with
treatment; 12 had marked improvement, two had moderate improvement
and two had mild improvement. Six of the people who had no treatment
also improved after they were no longer exposed to the pig brain
Neurologists have identified the illness as a new disorder that
is a sensory predominant polyradiculoneuropathy. The patients all
have a unique antibody not seen before. The disease affects the
nerves, and can usually be identified by standard tests (nerve
conduction studies and EMG), although in four mild cases specialized
tests were needed to detect the abnormalities. The disease seems to
improve with treatment and removal of exposure to pig brain.
The disorder likely has an autoimmune basis, with workers exposed
to the pig brains developing an autoimmune response that caused
nerve damage. The researchers hope that further studies on this
disease will aid understanding of other autoimmune disorders. "There
are other autoimmune disorders where the trigger is not known, so
this case with a known trigger could provide us with an opportunity
to understand how an antigen can trigger the body's immune system to
produce disease," said study author P. James B. Dyck, MD, of the
Mayo Clinic in Rochester, MN, and a Fellow of the American Academy
Additional details on the patients' testing and outcomes will be
presented at the AAN Annual Meeting.
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