Management:

A team was formed to review this case, and various expert bodies were consulted, including the NICD Outbreak Response Unit, an ethicist, the UK National CJD Research & Surveillance Unit and decontamination experts in South Africa and the United Kingdom.  

A risk assessment was done for instrumentation management:

Table 1: Risk assessment

Discussion

The risk of acquiring CJD is said to be about one person in every one million per year worldwide, although, in Europe where surveillance is enhanced, this figure rises to 2.5 per million per year.

Since the discovery of prion diseases, there have been 491 documented incidents of iatrogenic transmission, mostly resulting from prion-contaminated growth hormone (238 cases) and dura mater grafts (238 cases), one of which was described in the South African Medical Journal in 2006. Four cases were reported after gonadotropin treatment, four were transmitted by surgical instruments in the 1950s (UK and France), two by corneal transplant and two by electroencephalogram (EEG) depth electrode. There have been three reports of transmission of variant CJD by blood transfusion, although transmission risk remains theoretical to date.

Although fewer than 9 cases of probable iatrogenic neurosurgical cases of Creutzfeldt-Jakob disease (CJD) have been reported worldwide, the likelihood of some missed cases and the potential for prion transmission by neurosurgery create considerable concern.

(D. Bonda et al, 2016) 

Abnormal prions are unusually resistant to conventional chemical and physical decontamination methods, including high doses of ionizing and UV irradiation. Prions remain stable at a wide range of pH, are hydrophobic and resistant to most disinfectants. Of all micro-organisms, prions are the most resistant to disinfectants and sterilants, even more so than bacterial spores.

The probability of a surgical device remaining capable of transmitting disease depends on the initial load of contamination and effectiveness of cleaning, disinfection and sterilization.

Standard, effective cleaning of surgical instruments in the sterile services department results in only a 4 log10 reduction of microbes and about a 2 log10 reduction in protein contamination. Infectivity is stabilized by drying of tissues and by fixing with alcohol, formalin or gluteraldehyde.

Effects of cleaning methodologies on surgical instruments, according to S. Brown et al, 2004, include darkening of instruments, damaging of carbon steel and gold-plated instruments and welded and soldered joints. Damage becomes apparent after the first exposure.

Recommendations

• Treating physicians to have a high index of suspicion where patients might fit the criteria of diagnosis of CJD.
• Advise the Infection Prevention and Control Practitioner and the Sterile Services Manager as soon as possible – preferably before any surgery is planned or theatre booking is made.
• Perform intervention in an operating theatre
• Perform procedure at end of list – allows cleaning before next list
• Minimum no. personnel to be involved
• PPE – liquid repellent gown & mask; goggles & gloves (symptomatic patient – incinerate PPE; “at risk patient” – re-usable PPE may be re-processed)
• Shield complex instruments – drills and saws
• Use single use, disposable instruments & equipment where possible and destroy after use, or use the minimum number of instruments possible.
• Track instruments so they can be traced back to the patient they were used on. Surgical instruments that come into contact with high-risk tissues must not be moved from one set to another and must remain within their individual sets. All endoscopes should have a unique identifier and process register.
• Re-usable instruments – risk assess. Separate out instruments that came into contact with low infectivity tissue for re-processing and re-use
• Transport instruments to a previously designated area of Sterile Services Department in a closed container.
• Process instruments as soon as possible after use – do not allow them to dry out, keep them moist.
• High risk instruments should be cleaned of gross soil, taking care to avoid aerosols & splashing, under water but with water running and draining out continuously. Use a detergent cleaner with known efficacy against prions.
• Avoid contact with fixative agents such as alcohol and glutaraldehyde.
• Air dry then place in impervious rigid container and seal with heavy duty tape and label, including responsible person’s name and list of contents.
• If the diagnosis of the patient is positive, perform a risk assessment.
• If the risk is unacceptable, preferably incinerate instruments.
• Or quarantine high risk instruments for use on same patient if further surgery is likely.
• If instruments are to be disposed of, contact a reputable healthcare waste contractor. Instruments will have to be further treated before acceptance by the contractor. See different methodologies in the WHO guide: WHO Infection Control Guidelines for Transmissible Spongiform Encephalopathies, 2003.
• Clean contaminated working surfaces with hypochlorite at 10 000 ppm with contact time of 1 hour.
• Keep records of all decisions. 

Recommended reading

1. WHO Infection Control Guidelines for Transmissible Spongiform Encephalopathies: Report of a WHO Consultation, Geneva, Switzerland, 23-26 March 1999 - https://www.who.int/csr/resources/publications/bse/WHO_CDS_CSR_APH_2000_3/en/
   1. Although these guidelines were published about 20 years ago, they remain a valuable source of information for IPC concerns.
2. Rutala, W., Weber, D. (2010). Guideline for Disinfection and Sterilization of Prion-Contaminated Medical Instruments. Infection Control & Hospital Epidemiology, 31(2), 107-117.
   1. This guideline discusses in detail the decontamination and sterilization of prion-contaminated instruments.
3. CSSD Forums of South Africa (CFSA) Decontamination and Sterilisation Department Standard Operating Procedures updated 2019 contained in the: APPSA/SafMed. 2020. A Guide to Decontamination, Disinfection and Sterilization Practices. Enquiries re purchasing the guide: contact carma@gonet.co.za
   1. This is a South African document with guidelines on numerous decontamination processes. SOP 52 deals with prion-contaminated instruments.
4. Centers for Disease Control and Prevention CDC (2020). Prion Diseases. Available from https://www.cdc.gov/prions/index.html [accessed 5.2.2021]
5. National Creutzfeldt-Jakob Disease Research & Surveillance Unit (NCJDRSU), University of Edinburgh (2017). PROTOCOL Surveillance of CJD in the UK. Version 4, April 2017. https://www.cjd.ed.ac.uk/sites/default/files/NCJDRSU%20surveillance%20protocol-april%202017%20rev2.pdf
6. Bonda DJ, Manjila S, Mehndiratta P, Khan F, Miller BR, Onwuzulike K, et al. Human prion diseases: surgical lessons learned from iatrogenic prion transmission. Neurosurg Focus 2016;41:E10. - https://www.researchgate.net/publication/304708747_Human_prion_diseases_Surgical_lessons_learned_from_iatrogenic_prion_transmission
7. Crowder LA, Schonberger LB, Dodd RY, Steele WR. Creutzfeldt-Jakob disease lookback study: 21 years of surveillance for transfusion transmission risk. Transfusion 2017;57:1875e8. - https://onlinelibrary.wiley.com/doi/abs/10.1111/trf.14145
8. Toovey, S and Hewlett, R. A case of dura mater graft-associated Creutzfeldt-Jakob disease in South Africa July 2006, Vol. 96, No. 7 SAMJ - https://www.ajol.info/index.php/samj/article/view/13794
9. WHO tissue infectivity matrix - https://www.who.int/bloodproducts/tablestissueinfectivity.pdf
10. Brown, S.A., Merritt,T., Woods, T.Q., Busick, D.N., Effects on Instruments of the World Health Organization–Recommended Protocols for Decontamination after Possible Exposure to Transmissible Spongiform Encephalopathy– Contaminated Tissue. United States Food & Drug Administration. Published online 24 September 2004 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jbm.b.30125 - Available at: https://www.cdc.gov/prions/cjd/pdfs/effects-instruments-who-protocol-508.pd