The Centers for Disease
Control and Prevention (CDC)
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.
- 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.]
- 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.]
- 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.]
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
decontaminated by 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.
* 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.
CDC Web
Site where this information was obtained.
