SEARCH VEGSOURCE:

 

 

Follow Ups | Post Followup | Back to Discussion Board | VegSource
See spam or
inappropriate posts?
Please let us know.
  




From: TSS ()
Subject: UNDIAGNOSED NEUROLOGIC SYNDROME, PORCINE PLANT WORKERS - USA
Date: January 29, 2008 at 8:36 am PST

UNDIAGNOSED NEUROLOGIC SYNDROME, PORCINE PLANT WORKERS - USA (02):
(INDIANA, MINNESOTA)
******************************************************
A ProMED-mail post

ProMED-mail is a program of the
International Society for Infectious Diseases

[1] CDC: urgent bulletin
[2] CDC: letter to American Academy of Neurology (AAN)
[3] Neurology Today: upcoming article [7 Feb 2008]

******
[1] CDC: urgent bulletin
Date: Mon 28 Jan 2008
Source: Medscape Medical News [edited]


Prompted by reports of neurological symptoms among workers at 2 pork
processing plants in the USA, CDC [US Centers for Disease Control and
Prevention] has dispatched an urgent bulletin to all US neurologists
requesting information about any similar cases they may come across. The
CDC sent the bulletin to American Academy of Neurology (AAN) 17 Jan 2008;
it reports that clinicians at the Mayo Clinic in Rochester, Minnesota
notified the Minnesota Department of Health in the fall of 2007 about an
unusual cluster of 12 patients who developed inflammatory neuropathy
between November 2006 and November 2007.

All of the subjects worked in a pork processing plant in Austin, Minnesota,
in an area of the facility where the pigs' heads are processed. In
mid-January of 2008, there were reports of an additional cluster of
patients with similar symptoms among individuals working in a pig
processing plant in Indiana.

"In particular, neurologists who have diagnosed patients with peripheral
neuropathy, myelopathy, or a mixed clinical presentation of
peripheral/central (and, more specifically, myelopathic) involvement in
persons with exposure to pig butchering or processing during the past year
are asked to report this information to their state health department and
contact the CDC at (770) 488-7100."

--
communicated by:
ProMED-mail

******
[2] CDC: letter to American Academy of Neurology (AAN)
Date: Thu 17 Jan 2008
Source: American Academy of Neurology (AAN) website [edited]


In the fall of 2007, clinicians at the Mayo Clinic in Rochester, Minnesota,
notified the Minnesota Department of Health of an unusual cluster of 12
patients with inflammatory neuropathy occurring between November 2006 and
November 2007 among workers at a pork processing plant in Minnesota. An
initial investigation has revealed that they all have worked in the same
area of the plant where the heads of the pig are processed. The
investigation in Minnesota is ongoing and additional patients have been
identified in Indiana, among workers in a similar plant. At this point an
etiologic agent has not been identified.
These patients have frequently had illness onset with pain, numbness, and
tingling in the extremities. The illness typically progressed with
development of relatively symmetric mild to moderate weakness involving
predominantly the distal lower limbs. Occasionally, facial weakness has
also been observed. They often complain of difficulty with balance
(ataxia). Electrodiagnostic testing showed prolonged motor distal latencies
and F-wave latencies, minimal sensory nerve conduction abnormality, and
evidence of mild denervation of distal muscles on EMG (electromyography).
Of the cases in which cerebrospinal fluid (CSF) has been obtained, all have
had elevated CSF protein, with minimal if any pleocytosis (such as,
cytoalbuminologic dissociation). Thoracic and lumbar magnetic resonance
imaging has demonstrated mildly thickened nerve roots and contrast
enhancement. Time of illness progression ranged from several days to months
with severity of illness ranging from mild weakness in most cases to
paraplegia in one. Most have had some level of recovery.

Given the apparent close association of these patients with participation
in the processing of pig head material, it is possible that similar
illnesses are occurring at other pork processing plants. The CDC is
requesting neurologists to provide information about patients who may have
developed illnesses similar to that reported by the Mayo Clinic. In
particular, neurologists who have diagnosed patients with peripheral
neuropathy, myelopathy, or a mixed clinical presentation of
peripheral/central (and, more specifically, myelopathic) involvement in
persons with exposure to pig butchering or processing during the past year
are asked to report this information to their state health department, and
contact the CDC at 770-488-7100.

--
communicated by:
ProMED-mail

[More clinical information is given here but the issues of using air
pressure to extract the porcine brain in the plants where cases occurred is
not mentioned and what kind of personal protective equipment was used is
also not stated. - Mod.LL]

******
[3] Neurology Today: upcoming article [7 Feb 2008]
Date: Mon 28 Jan 2008
Source: American Academy of Neurology (AAN) website [edited]


An unusual illness in a dozen workers at a Minnesota pork processing plant
has state health officials concerned that the cluster could be an unknown
animal-borne nervous system disease.

All of the employees worked in an area where compressed air was used to
cleanse brain cavities, giving rise to speculation that the illness, health
officials are calling it an unknown inflammatory polyneuropathy, may have
been caused by exposure to an infectious agent in airborne brain
particulate matter.

Early reports suggested chronic inflammatory demyelinating polyneuropathy
(CIDP), which damages the myelin sheath surrounding nerves and typically
progresses for months. However, CIDP, as a specific diagnosis, was ruled
out after workers were examined by neurologists and had nerve conduction
studies.

According to Daniel Lachance MD, the Mayo Clinic neurologist who is caring
for many of the workers, "an astute nurse" at the plant brought the
symptoms to the attention of local Austin physicians, who in turn notified
the Mayo Clinic. Dr Lachance recognized the symptoms as being unusual. He
told Neurology Today in a telephone interview that while the illness shares
many similarities with CIDP, tests have shown it has a different signature.
Unlike CIDP, which is characterized by slowing or blocking of nerve
conduction, the workers' illness can be categorized only as an inflammatory
response that is attacking nerve roots proximally, and peripheral motor
nerves distally, he explained.

"While they do have electrophysiological evidence for peripheral nerve
involvement and the disorder appears associated with a remarkable
activation of the immune system, the clinical picture is different from
CIDP," he said...."the syndrome is best characterized as an inflammatory
polyradiculopathy."

"All of the information we have to date indicates that the general public
is not at increased risk for developing this type of illness," said
Minnesota commissioner of health Sanne Magnan MD PhD, in a news release.
"Also, there is no evidence that the foot supply has been affected."

Symptoms appeared over several weeks to months, characterized by muscle
weakness, paresthesias, especially in the legs, and chronic fatigue with a
sudden onset. In most patients, symptoms have been severe enough to limit
many daily activities, according to Dr Lachance, noting, for example, that
many have difficulty managing stairs. Symptoms were first noted in a worker
in a local soccer league when he could not continue playing. In some
patients, sensory symptoms and discomfort in the neck, lower back, and
limbs dominate the clinical picture, while in others, mild to moderate
weakness can be demonstrated on the neurological examination. Treatment has
generally consisted of observation in milder cases, while the more severely
affected have been treatment with steroids or intravenous immunoglobulins.

At press time, the Minnesota state health department had not identified a
cause of the illnesses. Investigators had interviewed all 12 patients, as
well as workers who worked in the same area and those who did not,
collecting information on work history, medical history, potential
exposures, and other topics. Clinical specimens, including throat swabs and
blood, were obtained from 90 per cent of those interviewed and evaluation
for possible infectious agents is ongoing.

All cases of the cases involved people who worked in an area where swine
heads are processed and brains removed. A compressed air system for
cleaning out the brain cavities of processed swine was introduced at the
plant shortly before the 1st worker complained of symptoms, and there has
been concern that the illness might have been caused by inhalation of
aerosolized brain tissue or a microorganism associated with this mode of
exposure.

The plant quickly stopped using the compressed air system and implemented
other measures to protect workers in early December 2007, and as of press
time, no new cases with symptom onset since the changes were made have been
reported, according to Dr Lachance.

Aerosolized blood and organ particulate in slaughterhouses and meat
processing plants, referred to as "blood mist" in occupational safety
circles, has long been recognized as a potential health risk and there are
regulations for worker exposure in the Occupational Health Act. Even so,
the symptoms do not match any known neurological illness that can be
transmitted from animals to humans.

Exposure to chemical toxins at the plant has been ruled out as a cause. To
date, no similar cases have been found in other states [as noted earlier in
the posting, there appears to be cases in an Indiana plant using the same
compressed air technique - Mod.LL] or elsewhere in Minnesota.

Because the workers were close to the brain removal area, concern was
raised that the pig CNS might be the infectious vehicle. "But we did not
know of any specific infectious or autoimmune disorder like this that is
caused by exposure to animal tissue," Dr Lachance said, adding the disorder
could be an autoimmune response to an infection. "Transverse myelitis or a
brachial plexopathy after a viral syndrome, Guillian-Barre syndrome
associated with _Campylobacter_ infection are the most likely models, but
to our knowledge, nothing like this has even been encountered before."

[byline: Kurt Samson]

--
communicated by:
ProMED-mail

[This piece states, of note, that the use of the compressed air technique
was started only shortly before cases began. The cause here may or may not
be an infectious agent but could be an immunologically reactive moiety such
as myelin.

More information is clearly needed here to better define this entity. -
Mod.LL

In a telephone call the MN epidemiologist reported that there is no
respiratory protection although full face shields are in use.- Mod.TG]

[see also:
Undiagnosed neuro. synd., porcine plant workers - USA: (IN, MN)
20080118.0226
2007
---
Undiagnosed neuro. synd., porcine plant workers - USA: (MN), RFI
20071204.3915]

.................ll/mj/sh


*##########################################################*
************************************************************

tss



Follow Ups:



Post a Followup

Name:
E-mail: (optional)
Subject:

Comments:

Optional Link URL:
Link Title:
Optional Image URL:

Unknown