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From: TSS (216-119-129-71.ipset9.wt.net)
Subject: Questions and Answers Regarding Creutzfeldt-Jakob Disease Infection-Control Practices
Date: November 5, 2004 at 9:58 am PST

-------- Original Message --------
Subject: Questions and Answers Regarding Creutzfeldt-Jakob Disease Infection-Control Practices
Date: Fri, 5 Nov 2004 09:02:50 -0600
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@UNI-KARLSRUHE.DE


Questions and Answers Regarding Creutzfeldt-Jakob Disease
Infection-Control Practices

The CJD infection control website is now updated to include THERE
experimental findings and articles on TSE and effects of decontamination
on instruments...TSS


BSE and CJD Home

Questions and Answers Regarding Creutzfeldt-Jakob Disease
Infection-Control Practices


What is Creutzfeldt-Jakob disease?

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, invariably
fatal neurodegenerative disorder believed to be caused by an abnormal
isoform of a cellular glycoprotein known as the prion protein. CJD
occurs worldwide and the estimated annual incidence in many countries,
including the United States, has been reported to be about one case per
million population.

The vast majority of CJD patients usually die within 1 year of illness
onset. CJD is classified as a transmissible spongiform encephalopathy
(TSE) along with other prion diseases that occur in humans and animals.
In about 85% of patients, CJD occurs as a sporadic disease with no
recognizable pattern of transmission. A smaller proportion of patients
(5 to 15%) develop CJD because of inherited mutations of the prion
protein gene. These inherited forms include
Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia.

How is CJD diagnosed?

Physicians suspect a diagnosis of CJD on the basis of the typical signs
and symptoms and progression of the disease. In most CJD patients, the
presence of 14-3-3 protein in the cerebrospinal fluid and/or a typical
electroencephalogram (EEG) pattern, both of which are believed to be
diagnostic for CJD, have been reported. However, a confirmatory
diagnosis of CJD requires neuropathologic and/or immunodiagnostic
testing of brain tissue obtained either at biopsy or autopsy.

Have there been any reports of iatrogenic transmission of CJD?

Yes, iatrogenic transmission of the CJD agent has been reported in over
250 patients worldwide. These cases have been linked to the use of
contaminated human growth hormone, dura mater and corneal grafts, or
neurosurgical equipment. Of the six cases linked to the use of
contaminated equipment, four were associated with neurosurgical
instruments, and two with stereotactic EEG depth electrodes.

All of these equipment-related cases occurred before the routine
implementation of sterilization procedures currently used in health care
facilities. No such cases have been reported since 1976, and no
iatrogenic CJD cases associated with exposure to the CJD agent from
surfaces such as floors, walls, or countertops have been identified.

How should surgical instruments used on suspected or confirmed
CJD patients be reprocessed?

Inactivation studies have not rigorously evaluated the effectiveness of
actual cleaning and reprocessing methods used in health care facilities.
Recommendations to reprocess instruments potentially contaminated with
the CJD agent are primarily derived from in vitro inactivation studies
that used either brain tissues or tissue homogenates, both of which pose
enormous challenges to any sterilization process.

The World Health Organization (WHO) has developed CJD infection control
guidelines
that can be a valuable guide to infection control personnel and other
health care workers involved in the care of CJD patients. Destruction of
heat-resistant surgical instruments that come in contact with high
infectivity tissues, albeit the safest and most unambiguous method as
described in the WHO guidelines, may not be practical or cost effective.

One of the most stringent chemical and autoclave sterilization methods
outlined in Annex III of the WHO guidelines (see below) can be used to
reprocess heat-resistant instruments that come in contact with high
infectivity tissues (brain, spinal cord, and eyes) and low infectivity
tissues (cerebrospinal fluid, kidneys, liver, lungs, lymph nodes,
spleen, and placenta) of patients with suspected or confirmed CJD. High
and low infectivity tissues were defined on the basis of available
experimental data as described in Table 2 of the WHO guidelines. The
stringent sterilization methods described below should be used to
reprocess medical instruments that come in contact with high infectivity
tissues of persons known to be blood relatives of patients with
inheritable forms of TSEs.

What are the chemical and autoclave sterilization methods
outlined in Annex III of the WHO infection control guidelines
for transmissible spongiform encephalopathies?

The three most stringent sterilization methods for heat-resistant
instruments described in Annex III of the WHO guidelines are listed
below; the alternatives are listed in order of more to less severe
treatments. Sodium hypochlorite may be corrosive to some instruments,
such as gold-plated instruments. Before instruments are immersed in
sodium hypochlorite, the instrument manufacturer should be consulted
about the instrument's tolerance of exposure to sodium hypochlorite.

1. Immerse in a pan containing 1N sodium hydroxide (NaOH) and heat in
a gravity displacement autoclave at 121°C for 30 min; clean; rinse
in water; and subject to routine sterilization.
[CDC NOTE: The pan containing sodium hydroxide should be covered,
and care should be taken to avoid sodium hydroxide spills in the
autoclave. To avoid autoclave exposure to gaseous sodium hydroxide
condensing on the lid of the container, the use of containers with
a rim and lid designed for condensation to collect and drip back
into the pan is recommended. Persons who use this procedure should
be cautious in handling hot sodium hydroxide solution
(post-autoclave) and in avoiding potential exposure to gaseous
sodium hydroxide, exercise caution during all sterilization steps,
and allow the autoclave, instruments, and solutions to cool down
before removal. An experiment conducted by Food and Drug
Administration (FDA) investigators indicated that the use of
appropriate containment pans and lids prevents escape of sodium
hydroxide vapors that may cause damage to the autoclave (Brown and
Merritt. Am J Infect Control 2003;31:257-260). PDF version

Adobe Acrobat Reader icon (86 KB)]
2. Immerse in 1N NaOH or sodium hypochlorite (20,000 ppm available
chlorine) for 1 hour; transfer instruments to water; heat in a
gravity displacement autoclave at 121°C for 1 hour; clean; and
subject to routine sterilization.
[CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]
3. Immerse in 1N NaOH or sodium hypochlorite (20,000 ppm available
chlorine) for 1 hour; remove and rinse in water, and then transfer
to open pan and heat in a gravity displacement (121°C) or porous
load (134°C) autoclave for 1 hour; clean; and subject to routine
sterilization.
[CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]

FDA investigators evaluated the effects to surgical instruments of the
steps involved in the sterilization protocols listed above; some of the
protocols they assessed subjected the instruments to harsher conditions
than those prescribed above. Their findings indicate that much of the
damage from autoclaving in sodium hydroxide was cosmetic and would not
affect the performance or cleaning of the instruments. Soaking in sodium
hydroxide had the least damaging effect on instruments, but immersion in
sodium hypochlorite bleach caused severe damage to some instruments. The
article summarizing the findings of this experiment by Brown et al. of
the FDA was published in the Journal of Biomedical Materials Research
(electronic version published October 2004) PDF version

Adobe Acrobat Reader icon (148 KB).

How should instruments used in patients with no clear diagnosis at the
time of a neurosurgical procedure be reprocessed?

In some patients undergoing neurosurgery, a CJD diagnosis that is not
suspected before the procedure may be confirmed after the neurosurgery.
For this group of patients, in whom the clinical diagnosis leading to
the neurosurgical procedure remains unclear, the instruments should be
reprocessed in the same manner as that for instruments used in
procedures involving suspected or confirmed CJD patients. Unless a clear
non-CJD diagnosis is established, these patients should be considered as
potentially suspected CJD patients for all other infection control
requirements.

How should heat-sensitive instruments or materials that come in
contact with suspected or confirmed CJD patients be decontaminated?

All disposable instruments, materials, and wastes that come in contact
with high infectivity tissues (brain, spinal cord, and eyes) and low
infectivity tissues (cerebrospinal fluid, kidneys, liver, lungs, lymph
nodes, spleen, and placenta) of suspected or confirmed TSE patients
should be disposed of by incineration. Surfaces and heat-sensitive
re-usable instruments that come in contact with high infectivity and low
infectivity tissues should be decontaminatedby flooding with or soaking
in 2N NaOH or undiluted sodium hypochlorite for 1 hour and rinsed with
water.
[CDC NOTE: Sodium hypochlorite may be corrosive to some instruments.]

What kinds of precautions should be taken while embalming the
bodies of patients with suspected or confirmed CJD?

An autopsied or traumatized body of a suspected or confirmed CJD patient
can be embalmed, using the precautions outlined in the WHO CJD infection
control guidelines
. CJD
patients who have not been autopsied or whose bodies have not been
traumatized can be embalmed using Standard Precautions. Family members
of CJD patients should be advised to avoid superficial contact (such as
touching or kissing the patient's face) with the body of a CJD patient
who has been autopsied. However, if the patient has not been autopsied,
such contact need not be discouraged.


Additional recommendations for CJD infection control practices not
addressed in this Q&A can be obtained from the "WHO Infection Control
Guidelines for Transmissible Spongiform Encephalopathies: Report of a
WHO Consultation, Geneva, Switzerland, 23-26 March 1999
."
Adobe Acrobat Reader icon PDF version (229 KB)

These documents are outside the CDC site.*

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* Links to nonfederal organizations found at this site are provided
solely as a service to our users. These links do not constitute an
endorsement of these organizations or their programs by CDC or the
federal government, and none should be inferred. The CDC is not
responsible for the content of the individual organization Web pages
found at these links.

http://www.cdc.gov/ncidod/diseases/cjd/cjd_inf_ctrl_qa.htm

TSS





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