Pig Brain Aerosolization related to Neuropathy.

[Guest guest]

Mad Cow,CSD, or are aerosolized brain proteins just not a good idea?

From MMWR

Investigation of Progressive Inflammatory Neuropathy Among Swine

Slaughterhouse Workers --- Minnesota, 2007---2008

On October 29, 2007, the Minnesota Department of Health (MDH) was

notified by a tertiary-care provider of unexplained neurologic

illnesses among workers in a swine slaughterhouse (plant A) in

southeast Minnesota. As a result, MDH initiated a detailed

investigation at plant A to characterize the outbreak. This report

describes the ongoing investigation and outbreak-control measures

undertaken by state public health officials and CDC.

Plant A, located in southeastern Minnesota, employs approximately 1,200

workers and processes 18,000 pigs per day. After being notified of the

illnesses, MDH investigators initiated active case finding, interviewed

workers at plant A, and reviewed the plant's occupational health and

employment records. As of January 28, 2008, a total of 12 workers at

plant A had been identified with confirmed (eight workers), probable

(two), or possible (two) progressive inflammatory neuropathy (PIN)

(Box). Illness onset ranged from November 2006 through November 2007.

Median age of the 12 patients was 31 years (range: 21--51 years); six

patients were female. All 12 patients reported being healthy before the

onset of neurologic symptoms.

Symptoms ranged from acute paralysis to gradually progressive symmetric

weakness over periods ranging from 8 to 213 days. Severity ranged from

minor weakness and numbness to paralysis predominantly in the lower

extremities affecting mobility. Eleven patients had evidence of axonal

or demyelinating peripheral neuropathy by electrodiagnostic testing.

Cerebrospinal fluid was obtained from seven patients. All seven had

elevated protein levels (median: 125 mg/dL; range: 75--231 mg/dL

[normal: 14--45 mg/dL]) with no or minimal pleocytosis (median: 1

cell/dL; range: 1--73 cells/dL in a nontraumatic tap); five patients

had evidence of inflammation on spinal magnetic resonance imaging (four

patients in peripheral nerves or roots and one patient in the anterior

spinal cord).

All 12 patients reported either working at or having regular contact

with an area where swine heads were processed (known as the head

table), which was located within a larger processing area in plant A

known as the warm room. A case-control study was conducted among plant

A workers to identify specific risk factors associated with illness.

The 10 patients with confirmed or probable cases were included in the

study, along with two stratified control groups: 1) a random selection

of 48 healthy warm-room workers and 2) all 65 healthy head-table

workers. Statistically significant (p<0.05) differences were calculated

by chi-square test. Blood samples and throat swabs were collected from

all consenting case-patients and controls. As of January 30, laboratory

investigations had not identified any infectious agent from the blood

and throat-swab specimens that would explain the occurrence of PIN.

Results of the case-control study indicated that case-patients (seven

of 10, 70%) were significantly more likely to have worked at the head

table than the warm-room controls (12 of 48, 25%) (odds ratio [OR]:

7.0; 95% confidence interval [CI] = 1.3--42.2; p = 0.009).

Case-patients also were more likely to have removed brains or remaining

skeletal muscle from the pig head (a process known as backing heads)

(four of 10, 40%) than controls (two of 46, 4%) (OR: 15.3; CI =

1.8--163.4; p = 0.006). Among head-table workers, case-patients were

significantly more likely to have removed brains or skeletal muscle

from the head (four of seven, 57%) than head-table controls (eight of

65, 12%) (OR: 9.50; CI = 1.40--70.2; p = 0.01). Illness was not

determined to be associated with previous travel outside or within the

United States; exposure to chemicals, fertilizers, or insecticides; use

of medications; or receipt of previous vaccinations.

An environmental assessment of the plant was conducted on November 28,

2007. Standard personal protective equipment (PPE) used by workers at

plant A included hard hats, laboratory coats (including some that were

short-sleeved), boots, hearing protection, eye protection, and

specialized gloves that varied with the particular task of the worker.

A compressed air device was used in the plant to harvest brain tissue

from pig heads at the head table. The device was placed into the skull

of the pig through the foramen magnum, and the force of the air

disrupted the brain material into a liquefied form that made it easier

to remove (a technique known as " blowing brains " ). This technique

caused generation of small droplets and splatter, possibly including

aerosolized brain material, to which workers operating the device and

others nearby might have been exposed. In response to the

investigation, plant A voluntarily suspended harvesting of brains and

instituted additional mandatory PPE on November 28, 2007, including

face shields and long sleeves, for workers stationed at the head table

and other workers who chose to use additional PPE.

Results of Case-Finding Survey

A survey of the 25 federally inspected swine slaughterhouses with >500

employees in the United States indicated that only three plants (plant

A in Minnesota and plants in Nebraska and Indiana) reported recent use

of compressed air to extract pig brains. To date, no cases of PIN have

been identified in association with workers at the Nebraska plant.

However, several workers at the Indiana plant have been preliminarily

identified with neurologic illnesses and similar histories of exposure

to head-processing activities at that slaughterhouse. Further

assessments of these patients, and additional measures to identify

other workers with illness, are being conducted in Indiana. As a result

of this investigation, all three plants have stopped using compressed

air to extract brain material.

Reported by: D Lachance, Mayo Clinic, Rochester; S Goyal, PhD, Univ of

Minnesota, St. ; R Danila, PhD, A DeVries, MD, R Lynfield, MD,

Minnesota Dept of Health. J Howell, DVM, J Wyatt, MPH, Indiana State

Dept of Health. T Safranek, MD, Nebraska Dept of Health and Human Svcs.

E Belay, MD, J McQuiston, DVM, L Schonberger, MD, J Sejvar, MD, Div of

Viral and Rickettsial Diseases; S Brueck, National Institute for

Occupational Safety and Health; J Adjemian, PhD, B Buss, DVM, J

Gibbins, DVM, S Holzbauer, DVM, EIS officers, CDC.

Editorial Note:

This report summarizes an ongoing investigation of PIN, a syndrome that

appears to be associated with swine slaughterhouse workers who process

pig heads. Several clinical and laboratory features of this illness and

the distinctive epidemiology associated with patients appear unique.

Pigs slaughtered at plant A have passed inspection by the U.S.

Department of Agriculture Food Safety and Inspection Service, and the

investigation has not identified any foodborne risk to the general

population.

The investigation in Minnesota indicates that PIN appears associated

with having worked at the head table, where a compressed-air device was

used to extract pig brains. In the process of blowing compressed air

into the pig skull, brain material might have been splattered or even

aerosolized, and workers might have been exposed through inhalation or

contact with mucous membranes. One hypothesis for development of PIN is

that worker exposure to aerosolized pig neural protein might have

induced an autoimmune-mediated peripheral neuropathy (1,2). Additional

investigation of the characteristics and causes of PIN is under way.

Whether compressed-air devices are being used for pig-brain extraction

in other slaughterhouses or processing facilities, in the United States

or internationally, is unknown. Clinicians should provide CDC with

information regarding swine slaughterhouse workers who might have

illnesses similar to PIN, including patients with peripheral

neuropathy, myelopathy, or features of both. Clinicians who identify

such patients should report the cases to their state health department

and contact CDC at .

References

1. 1. Quattrini A. Inflammatory neuropathies. Neurol Sci 2005;26:S6.

2. 2. Tatsumoto M, Koga M, Gilbert M, et al. Spectrum of

neurological diseases associated with antibodies to minor gangliosides

GM1b and GalNAc-GD1a. J Neuroimmunol 2006;177:201--8.

[Guest guest]

Have they excluded any possibility of prion-based disease, like BSE

(mad cow disease) or scrapie?

If not this may be very scary for them and it would not have a good prognosis.

Brain tissue is known for transmitting these " transmissible spongiform

encephalopathies "

Prions are the smallest known pathogens and they are not destroyed by cooking.

They are very very scary!

Good reasons to consider vegetarianism!

[Guest guest]

Quack:

The issue that this article beings-up has nothing to do with vegetarianism, it has more to do with an engineering control (or lack thereof) in a work setting, i.e., don’t blow brains out of their skulls using compressed air. There are a lot of don’ts when using compressed air, and the meat packing industry should take note of them. Blowing brains seems to be one.

Have they excluded any possibility of prion-based disease, like BSE

(mad cow disease) or scrapie?

If not this may be very scary for them and it would not have a good prognosis.

Brain tissue is known for transmitting these " transmissible spongiform

encephalopathies "

Prions are the smallest known pathogens and they are not destroyed by cooking.

They are very very scary!

Good reasons to consider vegetarianism!

[Guest guest]

That's not what I was mainly getting at, did it seem that way?

Actually, I belong to PWETA

People Who Eat Tasty Animals (trying to make a joke there)

Ive been a vegetarian in the (semi distant) past and do admire them

and it to some extent, but currently eat meat..

But vegetarianism does have that unique benefit of being theoretically

safer from prion-based disease (although I suppose one

could still possibly get them from cooking utensils that had been used

to prepare contaminated meat, given as the temperature to 'deactivate'

prions is allegedly so high..)

>

> Quack:

>

> The issue that this article beings-up has nothing to do with vegetarianism,

> it has more to do with an engineering control (or lack thereof) in a work

> setting, i.e., don't blow brains out of their skulls using compressed air.

> There are a lot of don'ts when using compressed air, and the meat packing

> industry should take note of them. Blowing brains seems to be one.

>

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>

> Have they excluded any possibility of prion-based disease, like BSE

> (mad cow disease) or scrapie?

>

> If not this may be very scary for them and it would not have a good

> prognosis.

>

> Brain tissue is known for transmitting these " transmissible spongiform

> encephalopathies "

>

> Prions are the smallest known pathogens and they are not destroyed by

> cooking.

>

> They are very very scary!

> Good reasons to consider vegetarianism!

>

>

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>