RE: Process of tissue with CJD
Rita Riddle wrote:
CJD is not "enhanced" by formalin. Formalin simply does not deactivate the
prion, so any formalin fixed tissue or block (or block shavings) is still
Here are some resources for handling CJD cases. If you know for sure it is a
CJD case you should either send it to a lab that specializes in these or
wait until you have the proper setup to handle it.
For really good information about the practicalities of dealing with CJD lab
Jennifer Hofecker, HT, Dept of Pathology, Univ. of Rochester Medical center,
Box 626, Rochester, NY, 14642. PH(W): 716-275-3196, email:
Jennifer has put on workshops at the NSH meetings and has a lot of printed
material on how to set up a lab for CJD work.
Handling Creutzveldt-Jakcob disease Tissues in the Histology Laboratory,
Titford, M. and Bastian, F.O., J Histotech, V12, No.3 Sept 1989
If you have access to the internet you can go to these sites:
Search Altavista for "CJD" at http://www.altavista.digital.com
there are many articles concerning CJD and V-CJD from Britain.
CAP: Detailed information on handling CJD in the autopsy suite and the lab,
For all CDC information on CJD, go to to the main CDC web page and search
for "CJD" :
CJD Epidemiology, risk factors and decontamination:
Udatated info at (reproduced below)
AGENT: Transmissible Spongiform Encephalopathies (Creutzfeldt-Jakob, kuru
and related agents)
Laboratory-associated infections with the transmissible spongiform
diseases) have not been documented. However, there is evidence that
disease (CJD) has been transmitted iatrogenically to patients by
corneal transplants, dura
mater grafts and growth hormone extracted from human pituitary glands,
and by exposure
to contaminated electroencephalographic electrodes (99). Infection is
always fatal. There is
no known nonhuman reservoir for CJD or kuru. Nonhuman primates and
animals have been infected by inoculation, but there is no evidence of
transmission. Scrapie of sheep and goats, bovine spongiform
encephalopathy and mink
encephalopathy are transmissible spongiform encephalopathies of animals
that are similar to
the human transmissible diseases. However, there is no evidence that
the animal diseases
can be transmitted to man.
LABORATORY HAZARDS: High titers of a transmissible agent have been
the brain and spinal cord of persons with kuru. In persons with
and its Gerstmann-StrSussler-Schenker Syndrome variants, a similar
transmissible agent has
been demonstrated in the brain, spleen, liver, lymph nodes, lungs,
spinal cord, kidneys,
cornea and lens, and in spinal fluid and blood. Accidental parenteral
of nerve tissues, including formalin-fixed specimens, is extremely
non-nerve tissues are less often infectious, all tissues of humans and
animals infected with
these agents should be considered potentially hazardous. The risk of
infection from aerosols,
droplets, and exposure to intact skin, gastric and mucous membranes is
however, there is no evidence of contact or aerosol transmission. These
characterized by extreme resistance to conventional inactivation
irradiation, boiling, dry heat and chemicals (formalin,
however, they are inactivated by 1 N NaOH, sodium hypochlorite (>2%
concentration) and steam autoclaving at 134 degrees C for 1 hour.
RECOMMENDED PRECAUTIONS: Biosafety Level 2 practices and facilities are
for all activities utilizing known or potentially infectious tissues
and fluids from
naturally-infected humans and from experimentally infected animals.
Extreme care must be
taken to avoid accidental autoinoculation, or other traumatic
parenteral inoculations of
infectious tissues and fluids (76). Although there is no evidence to
suggest that aerosol
transmission occurs in the natural disease, it is prudent to avoid the
generation of aerosols
or droplets during the manipulation of tissues or fluids, and during
the necropsy of
experimental animals. It is further strongly recommended that gloves be
worn for activities
that provide the opportunity for skin contact with infectious tissues
Formaldehyde-fixed and paraffin-embedded tissues, especially of the
infectious. It is recommended that formalin-fixed tissues from
suspected cases of
transmissible encephalopathy be immersed in 96% formic acid for 30
histopathologic processing (15). Vaccines are not available for use in
A PREVIOUS HISTONET DISCUSSION:
-- 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 appreciated. Thanks in
Cathy Goeden HT(ASCP)
VAMC Sioux Falls, SD
From: Rose Richardson [mailto:email@example.com]
Sent: Tuesday, August 14, 2001 10:23 AM
For this situation I would recommend 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.
From: firstname.lastname@example.org (Wenk, Lee & Peggy) Save Address Block Sender
To: "Carson, Karla"
Subject: Re: CJD
Date: Wed, 21 Jul 1999 21:52:34 -0400
NSH just had a teleconference on this TODAY - Wed. July 21, 1999.
Contact the NSH office at 301-262-6221. Ask them for Jennifer's
phone number, the person who gave the teleconference today. I
forget her last name, and I'm at home, and that's at work.
You really need a good procedure. THIS IS NOTHING TO GOOF UP ON.
Basically, you will need to fix the tissue in 10% NBF for several
days, place it in 90% formic acid for an hour, go back into NBF,
hand process in plastic dishes, collect all the fixation and processing
solutions and dishes for special sterilization and incineration,
wear all the personal protective equipment you can, cover your
microtomes with plastic wrap or aluminum foil to collect all
the shavings (to be sterilized and incinerated), hand stain
in plastic disposable containers (and again collect all
staining solutions to be sterilized and incinerated).
I hope someone will be able to contact Jennifer early
tomorrow, or that someone will be able to email you their
procedure. (Sorry, I got a new computer at work, and literally
cannot do a thing with it. But that's another story.)
Also, maybe someone can email you the address of the
Histonet archives. I can't find my bookmark on it.
I know this has been discussed before, so you might be able
to find a procedure from previous postings.
Peggy A. Wenk, HTL(ASCP)
William Beaumont Hospital
Royal Oak, MI 48073
ANOTHER PREVIOUS HISTONET DISCUSSION:
CJD References for NaOH use
There are numerous references for using sodium hydroxide as a
Two that first come to mind are "Tissue Handling in Suspected Creutzfeldt -
Jakob Disease and Other Human Spongiform Encephalopathies (Prion Diseases)"
published in Brain Pathology 1995 by Herbert Budka et al . Another good
reference is Dr. Barbara Crain's article in CAP Today, January 1996:
"Safety Tips for anatomic studies of possible CJD. There are different
opinions on what concentration of NaOH to use, but many agree on its
effectiveness. I agree, it is definitely better to deactivate prion prior
to processing with formic acid treatment of tissues.
My reason for encouraging sodium hydroxide use is as an alternative to
bleach. Sodium Hydroxide is more stable than bleach which must be used
Hope this helped,
Jennifer Hofecker, HT (ASCP)
University of Rochester
From: Rita Riddle [mailto:RitaR@lexhealth.org]
Sent: Wednesday, January 16, 2002 10:59 AM
To: Histology (E-mail)
Subject: Process of tissue with CJD
Need your help,
Does anyone know if any special handling of formalin-fixed brain tissue and
paraffin blocks obtained from patients with Creutzfeldt-Jakob disease is
required by any known standard? I've read that formalin actually enhances
prion infectivity and that a formalin-formic acid procedure is required for
inactivation of such tissue samples. Can such tissues be disposed of in the
usual manner? Thanks
Lexington Medical Center
West Columbia, SC
Supervisor of Histo/Surgical Pathology
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