Current Issues Regarding Disinfection & Sterilization of Prion Contaminated Medical Instruments

1
Current Issues Regarding Disinfection
Sterilization of Prion Contaminated Medical
Instruments

• Jeannie Druckenmiller
• Wisconsin Division of Public Health
• 2011

2
Incident 2009

• Patient with rapidly progressive dementia
• Tumor found, bx done not malignant no
  histology indicating prion disease
• Pt mental status continues to rapidly deteriorate
  
• CJD discovered at full brain autopsy
• Bx instruments used on gt 50 other patients

3
Incident 2009 cont.

• Per hospital policy, the biopsy on the tumor was
  considered to be neuro-surgery on a
  space-occupying lesion, hence Infection
  Prevention was not notified in advance

4
2010 SHEA Guideline to Disinfection and
Sterization of Prion-Contaminated Medical
Instruments

• Rutala WA, Weber DJ. Guideline for disinfection
  and sterilization of Prion-Contaminated Medical
  Instruments. Infect Control Hosp Epidemiol
  201031107-117.
• http//www.unc.edu/depts/spice/dis/ICHE-2010-Feb-p
  107.pdf
• Letter from CDC, Belay et al, Dec 2010
• Reply from Rutala to Belay letter

5
2010 SHEA Guideline cont.Background

• Iatrogenic transmission of CJD described in
  humans in only 3 circumstances
• Intracranial electrodes/neuro surgery
• Cadaveric growth hormone therapy
• Contaminated grafts from human tissue (dura
  matter gt190 cases) processed prior to 1987 and
  corneas (2 cases)
• Rutala and Weber, 2010

6
2010 SHEA Guideline cont.Background

• Summary All known instances resulted from
  exposure to infected brain, pituitary or
  posterior eye tissue.
• Rutala and Weber, 2010

7
2010 SHEA Guideline cont.Background

• No known cases transmitted by contaminated
  medical instruments in past several decades (gt30
  yrs)
• Transmission is inefficient and current cleaning
  and disinfection methods, though suboptimal may
  be preventing disease.

8
2010 SHEA Guideline cont.Background

• Studies of iatrogenic-associated CJD from
  1952-1976 are missing important details regarding
  methodology of reprocessing.
• No known cases attributable to reuse of devices
  or associated with transfusion of blood products.

9
2010 SHEA Guideline cont. Background

• Prions exhibit extreme resistance to conventional
  methods of disinfection / sterilization
• Past studies have NOT detailed the reprocessing
  procedures
• 1) did not incorporate a cleaning step
• Can reduce microbial load 4-6 log10
• Many studies have shown effectiveness of these
  products to eliminate infectivity of prions

10
2010 SHEA Guideline cont.Background

• 2) studies have been done using tissue
  homogenates (lumps of tissue). The tissue
  protects the prion and may be the reason the
  prion is so difficult to destroy.
• 3) Studies have involved differing methodologies

11
2010 SHEA Guideline cont.

• What we do know
• Chlorine and NaOH provide the most consistent
  inactivation results but are corrosive to
  instruments and sterilizers and harmful to
  workers
• Certain enzymatic cleaners and alkaline
  detergents do inactivate prions
• Ethylene oxide does not work

12
2010 SHEA Guideline cont.

• What we do know
• Transmission based on instrument contact with
  infected pt must retain its infectivity and
  that of adhering tissue after disinfection /
  sterilization must make contact with a
  receptive tissue (patient).

13
2010 SHEA Guideline cont.

• The recommendations in this guideline are
  designed to break the chain of transmission and
• Are predicated on epidemiological
  (evidence-based) studies. Other studies have been
  based on inactivation studies using lumps of
  tissue.

14
2010 SHEA Guideline cont.

• Review The 3 Parameters to consider
• Patients risk of having prion disease
• Comparative infectivity of body tissue(s)
  involved
• Intended use of the medical device

15
2010 SHEA Guideline cont.

• At risk patient
• Rapidly progressive dementia
• Ataxia (movement disorder)
• Positive CSF 14-3-3 / tau protein / NSE
• MRI and/or EEG consistent with CJD
• Known risk history of dura matter or growth
  hormone transplant
• No other diagnosis to support S S
• No. 3 - 6 may not be present

16
2010 SHEA Guideline cont.

• At risk tissues
• High risk brain, spinal cord, posterior eye
  (including retina, cornea and optic nerve),
  pituitary
• Low risk CSF, liver, lymph, kidney, lung,
  spleen, placenta, olfactory epithelium

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2010 SHEA Guideline cont.

• No risk blood / blood products / components,
  bone marrow, peripheral nerves, intestine, heart,
  skeletal muscle, adipose, gingival, prostate,
  tears, saliva, sputum, urine, feces, sweat,
  breast milk, vaginal secretions, thyroid
• Rutala and Weber, 2010

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2010 SHEA Guideline cont.

• Review Spauldings Principles
• Critical device enters sterile tissue or
  vascular system
• Semi-critical contact non-intact skin or mucous
  membranes
• Special reprocessing necessary for these devices
  if potentially prion contaminated

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2010 SHEA Guideline cont.

• Recommendations
• Keep instruments wet until decontamination takes
  place
• Immerse in water or prioncidal detergent
  (references included)
• Do not let them dry out
• Decontaminate (clean) in automated washer
  disinfector ASAP after use to remove tissue

20
2010 SHEA Guideline cont.

• Recommendations
• After cleaning options
• 134C for 18 min pre-vacuum
• 132 C for 1 hr gravity displacement
• 1 N NaOH for 1 hr rinse with water, autoclave in
  open pan (121 or 134C)
• 1N NaOH for 1 hr, heat in gravity displacement
  at 121C 30 min, then clean and routine
  sterilize
• Rutala and Weber, 2010

21
2010 SHEA Guideline cont.

• Recommendations
• Discard devices impossible to clean
• Do not use flash sterilization
• Recall contaminated items from pts later
  diagnosed with prion disease and reprocess using
  prion guideline protocol
• Establish policies for all pts undergoing brain
  biopsy

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2010 SHEA Guideline cont.

• Recommendations
• No recommendation for prion reprocessing for
  critical or semi-critical devices contaminated
  with low-risk tissue from a high risk patient.
• Autopsy and research lab surfaces contaminated
  with high-risk tissue should be decontaminated
  with 15 bleach, contact time 15 min
• Rutala and Weber, 2010

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2010 SHEA Guideline cont.

• Recommendations
• Quote from the authors we have included only
  those options for which scientific studies have
  best demonstrated both safety (for equipment and
  operator) and efficacy.
• Rutala and Weber, 2010

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2010 SHEA Guideline cont.

• Recommendations
• Environmental surfaces contaminated with no risk
  tissue from high-risk patients require standard /
  routine disinfection.
• Rutala and Weber, 2010

25
2010 SHEA Guideline cont.

• Recommendations
• Consider using these recommendations for
  non-specific brain biopsies done on all patients
  with a non-space occupying lesion or
• Use disposable instruments or
• Routinely quarantine instruments

26
2010 SHEA Guideline cont.

• Recommendations
• If prion disease discovered after the fact,
  recall and reprocess instruments using special
  processes previously described, or
• Discard the instruments
• To do this you need a detailed tracking system

27
2010 SHEA Guideline cont.

• General IP Precautions for prion disease
• Standard precautions
• No special precautions for food, utensils or
  environmental cleaning, disposal of blood or body
  fluids
• No evidence of occupational transmission
• No need to discard expensive lab or central
  processing instruments

28
2010 SHEA Guideline cont.

• This document has been endorsed by
• SHEA
• APIC
• AORN
• AAMI
• This guideline will be updated as appropriate
  if/when scientifically proven new technologies
  are available.
• Rutala and Weber, 2010

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Reply from Belay et al, CDC to Rutala and Weber
December 2010 ICHE / SHEA Journal

• Recommendations are contrary to those endorsed by
  other recognized experts in the field
• Contrary to the WHO 1999 Guideline
• Lack of reported iatrogenically transmitted cases
  may not be as reassuring as Rutala and Weber
  assert
• CDC, FDA, NIH continue to endorse WHO 1999
  protocol

30
Reply from Rutala and Weber to Belay et al

• 1) WHO document is not an evidence-based
  guideline and does not list the scientific
  studies used to support it
• 2) Agree the perfect test system type of study
  does not exist, but believe efficacy of protocols
  should place greater weight on studies
  representative of current standard instrument
  reprocessing
• 3) Rutala/Weber place more weight on lack of
  reported iatrogenic cases
• 4) Careful review of studies indicates
  conflicting results, probably due to use of
  different methodology

31
Reply from Rutala and Weber to Belay et al

• 5) Disagree with Belay et al on determination of
  mean infectivity likely present in human brain
• 6) Agree instruments should be kept moist until
  cleaned
• 7) Protocols in SHEA Guideline are consistent
  with SHEA, APIC, AORN, AAMI

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The Controversy continues

• Which document should you use?
• What about cataract surgery?
• What about automated, expensive lab instruments?

33
The Controversy continues

• Which document should you use?
• WHO vs Rutala Weber
• ??

34
The Controversy continues

• What about cataract surgery?
• Risk of transmission from routine cataract
  surgery is unknown. CDC is unaware of this ever
  having occurred.
• Eye surgery of any kind on a suspect or known CJD
  pt should be done with disposable instruments or
  instruments must be reprocessed according to
  prion protocol
• CDC website

35
The Controversy continues

• What about automated, expensive lab instruments?
• In CSF is not a high risk tissue. No need to
  decontaminate or discard the automated lab
  analyzers
• Rutala and Weber, 2010

36
Establishment of hospital policy and procedures
37
Hospital Policy and Procedures for Neurosurgery

• Increase level of awareness of prion disease in
  all surgery cases involving high risk tissue
• Establish high level of communication between OR
  and IP
• Ensure policies and procedures are up to date

38
Hospital Policy and Procedures for Neurosurgery

• Policy should include
• If prion disease is suspected after surgery,
  instruments involved will be recalled and
  properly reprocessed.
• Instruments that cannot withstand prion
  reprocessing will be discarded
• Designated coordination of exposure response, if
  necessary

39
Hospital Policy and Procedures for Neurosurgery

• Policy should include
• All patients undergoing surgery to brain, spinal
  cord or eyes should be screened for SS
  suggestive of prion disease
• Notification that a patient with possible prion
  disease should be made to a defined group of
  people (e.g., IP, hospital epidemiologist, OR)
• Surgery on such pts will be with disposable
  instruments

40
Hospital Policy and Procedures for Neurosurgery

• Policy should include
• Training requirements
• Safety issues (OSHA)
• Forms necessary (e.g., pt screening)
• References
• Responsibility for policy coordination
• Review process with by affected departments

41
Hospital Policy and Procedures for Neurosurgery

• Procedure should include
• Prion disease should be considered in any pt with
  rapidly progressive dementia and/or movement
  disorders
• Pt screening for prion disease shall be performed
  on all pts scheduled for surgery on brain, spinal
  cord, eye
• Designate who will screen pt
• Parameters for screening

42
Hospital Policy and Procedures for Neurosurgery

• Procedure should include
• In event of possible or confirmed case
• Notification of persons responsible for
  coordinating response
• Be specific (e.g., IP, OR, CS, pathology, lab,
  Env. Services, etc.)
• Delineate responsibilities of these individuals

43
Hospital Policy and Procedures for Neurosurgery

• Procedure should include
• Delineate exact precautions to be used during
  surgery
• Disposable instruments if possible
• If using reusable instruments, they should be
  sequestered, kept moist, etc
• Instrument quarantine details
• Removal of unnecessary equipment prior to
  procedure
• Schedule as last case of the day

44
Hospital Policy and Procedures for Neurosurgery

• Procedure should include
• Enhanced cleaning of contaminated OR or lab
  surfaces (concentration, contact time)
• Enhanced reprocessing of instruments include
  detailed check list
• Those which are disposable
• Those which can withstand prion reprocessing
• Quarantine parameters for others
• Bin / instrument labeling

45
Hospital Policy and Procedures for Neurosurgery

• Procedure should include
• Re quarantined instruments
• What to do if prion disease if definitively ruled
  out
• What to do if prion disease is confirmed
• Any special handling issues

46
Questions / Comments
47
2010 SHEA Guideline cont.

• Transmission to 2 pts via brain electrodes is
  only proven transmission via a medical device
• Implanted in known CJD pts
• Then cleaned and sterilized with benzene and
  70 alcohol formaldehyde vapor
• 2 years later - retrieved and implanted in
  chimpanzee which eventually developed the disease