Re: Daily Digest
|From:||Rose Richardson <email@example.com>|
For this situation I would recomend to use an autoclave if you have metal
buckets, or if the parts are not stable to the heat use 2M NaOH or 10%
bleach, wipe down and let stand for an hour then rinse. Included is the CAP
protocol for known CJD.
I have worked with CJD for 15 years and if you have further questions please
feel free to contact me.
Safety tips for anatomic studies of possible CJD
* Precautions for tissue handling in the autopsy room
Decontaminating the autopsy room
Decontaminating the tissue
* Precautions for tissue handling in the histology lab
Handling slides and blocks
Barbara J. Crain, MD, PhD
Identifying cases at risk for Creutzfeldt-Jakob Disease (CJD)
All brain biopsies for dementia should be handled as possible CJD cases. No
frozen sections should be done.
1. In cases of neurodegenerative disease, examine the chart carefully for
specific mention of CJD, spongiform encephalopathy, or other prion diseases.
Irrespective of the clinical diagnosis, examine the chart for any of the
following: rapidly progressive dementia; dementia less than three years
total duration; signs or symptoms of cerebellar disease; dementia
accompanied by lower motor neuron findings; demential accompanied by any
focal neurologic deficit not explainable on the basis of documented
structural disease (e.g., infarct, tumor); dementia with seizures,
especially myoclonic seizures early in the disease course; previous dural
implants; or human growth hormone treatment. If any of these warning signs
is present, discuss the case with a neuropathologist or the attending
2. If there is any suspicion of CJD, the autopsy should be limited to the
brain only and the tissue treated as outlined below. Exceptions to this rule
should be very few.
Precautions for tissue handling in the autopsy room
1. Follow universal precautions against conventional bloodborne agents;
cut-resistant gloves are preferable.
2. Wear a mask and eye shield, although there is no evidence that CJD is
transmitted by aerosols or by nonpenetrating mucosal contamination.
3. Confine all tissues and fluids (including running water) to the table.
4. This may be facilitated by placing a plastic sheet over the table. Remove
the calvarium with a hand saw if possible. If a Stryker saw is used, use
some form of shielding (such as a plastic bag) to contain small drops of
blood and tissue.
5. Do not contaminate the outer surface of the specimen container.
6. Clearly, label the container as infectious and place in a similarly
labeled secondary container. Notify the funeral home of the infectious
nature of the case.
Decontaminating the autopsy room
1. Wash the area of the incision and any other contaminated skin surfaces
with freshly opened undiluted commercial bleach (sodium hypochlorite).
After 10 minutes, wash off the bleach with water.
2. Place all gowns, gloves, plastic sheets, and other disposable supplies in
"biohazard" bags and incinerate them. Alternatively, autoclave (132 degrees
Celsius steam) the disposables and discard them. Disinfect any liquids on
the autopsy table with an equal volume of bleach or 2 normal sodium
hydroxide (2N NaOH) before disposing.
3. Decontaminate hard surfaces and surgical instruments with bleach or 2N
These two treatments are equally efficacious; the choice between them
depends on convenience and the material being decontaminated. NaOH is
preferred for steel instruments because it is less corrosive than bleach.
Leave the disinfectant in contact with the surface for at least 15 and
preferably 60 minutes.
Decontaminating the tissue.
1. The strongly preferred approach is formalin fixation followed by formic
acid treatment of tissue blocks.
i. Fix the intact brain in formalin for at least 10 days prior to cutting.
Agitate the tissue blocks (including at least one section from each cortical
lobe, basal ganglia plus cerebellum) in at least 50-100 mL of 95 percent-100
percent formic acid for one hour and then return them to formalin for two
days prior to embedding.
ii. Alternatively, take the necessary diagnostic sections from the fresh
brain; fix them in formalin for two to seven days (as one would a surgical
biopsy for dementia), treat with formic acid for one hour, and fix again in
formalin for two days.
iii. The formic acid treatment significantly reduces infectivity, although
it does interfere with some silver stains for the plaques and tangles of
2. Retain the remaining brain tissue until a diagnosis has been made.
3. If the initial sections show CJD, proceed with a workup for Alzheimer's
disease and other dementias.
Precautions for tissue handling in the histology lab
Tissue processing and sectioning.
1. Tissue treated with formic acid is essentially decontaminated and may be
processed routinely, although many histology laboratories still prefer hand
processing. Treat hand-processed material as potentially infectious.
2. Wear double gloves at all times.
3. Treat all solutions with equal volumes of fresh undiluted bleach for 60
minutes before disposal.
4. Handle disposables, glassware, tools, etc. according to the procedures
used in the autopsy room (see preceding comments).
5. Collect all scraps of paraffin and unused sections on a disposable sheet.
6. Use disposable microtome blades.
7. The microtome itself may be wiped with bleach or sodium hydroxide
solution, but it obviously cannot be thoroughly decontaminated. Laboratories
that frequently handle possible CJD cases may wish to dedicate an old
microtome to this purpose.
Handling slides and blocks
1. No special precautions are needed in handling intact glass slides once
they have been coverslipped. Decontaminate and discard broken slides.
2. Paraffin blocks should be stored in a properly labeled bag or box.
1. Brown P. Guidelines for high-risk autopsy cases: special precautions for
Creutzfeldt-Jakob disease. In: Hutchins G, ed. Autopsy Performance and
Reporting, Northfield, Ill.: College of American Pathologists; 1990:68-74.
2. Brown P, Wolff A, Gajdusek DC. A simple and effective method for
inactivating virus infectivity in formalin-fixed tissue samples from
patients with Creutzfeldt-Jakob disease. Neurology. 1990;40:887-890.
Dr. Crain, of the Department of Pathology, Johns Hopkins Hospital,
Baltimore, is a member of the CAP Neuropathology Committee. Her article is
one of a periodic series of articles written by the members of committees
composing the CAP Commission on Anatomic Pathology.
----- Original Message -----
To: HistoNet Server <firstname.lastname@example.org>
Sent: Monday, August 13, 2001 5:57 PM
Subject: RE: Daily Digest
-- Original Message --
I am wondering if someone is willing to share a procedure for
a tissue processor after processing a Creutzfeldt-Jacob case (unknowingly).
Do I use formic acid or should I use fresh 10% bleach? I am updating
for JCAHO inspection and any information would be appreci
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