Current Issue: Volume 16 Number 51	Published on: 21 December 2006	Current Issue in PDF PDF format (283 Kb)

Emerging infections/CJD

Last updated: 14 December 2006, Volume 16, No. 50 (PDF file, KB) Next update: 14 December 2006

Emerging infections/CJD Archives: | 2006 | 2005 |

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Creutzfeldt-Jakob disease (CJD) update report

This six-monthly report provides an update on reports of incidents of potential iatrogenic (healthcare-acquired) exposure to CJD via surgery, and on the National Anonymous Tonsil Archive. Data is correct as of 12 December 2006.

For numbers of CJD case reports, readers should consult data provided by the national CJD Surveillance Unit (NCJDSU), Edinburgh [1]. The latest quarterly analysis of vCJD reports (onsets and deaths) is also available from the NCJDSU website [2].

Reports of incidents of potential iatrogenic exposure to CJD via surgery 01January 2000 to 30 June 2006

There were 281 incidents in this period: 53 surgical incidents were reported to the CJD Incidents Panel (Panel) in 2005 and 28 in the first half of 2006 (table 1). Surgical incidents occur when instruments considered potentially contaminated with the CJD agent during use on an index patient have been subsequently re-used on other patients. A patient whose surgery results in potential contamination of instruments with prions is referred to as the index patient. Table 1 shows the number of CJD surgical incidents reported to the Panel from January 2000 to June 2006 by the diagnosis of the index patient.

Table 1 CJD surgical incidents reported to the CJD Incidents Panel: between January 2000 and June 2006, by diagnosis of index patient

Investigation of surgical incidents may result in advice to remove surgical instruments from clinical use (to quarantine, destroy, or donate for research). Such advice is generally only given for instruments considered to be potentially contaminated with the CJD agent that have not undergone sufficient number of cycles of use and decontamination since their use on an index patient. Hospitals are asked to consider sending any instruments to be permanently removed from use to the Surgical Instrument Store (held by the Health Protection Agency, Centre for Emergency Preparedness and Response, Porton Down) for research.

Instruments were quarantined or permanently removed from use on other patients in 55 incidents reported between January 2000 and June 2006. 11 of these incidents were reported in 2005 and four incidents were reported in the first half of 2006. The Panel may advise contacting and informing some patients of their possible exposure to CJD in a surgical incident. Such advice is generally only given for patients who have definitely been exposed to potentially contaminated instruments which have been used on risk tissues in certain index patients. The Panel advises that these patients should be considered 'at-risk of CJD for public health purposes' and asked to take certain precautions (i.e. not to donate blood or other tissues and to inform their medical and dental carers prior to any invasive procedures) in order to reduce the risk of transmitting the CJD agent to other patients. Since 2000, 16 incidents have given rise to advice to contact and inform subsequent patients of their potential exposure to CJD (Table 2). The Panel advised that 70 patients should be contacted and informed that they are 'at-risk' of CJD for public health purposes. Subsequently, based on updated risk assessments, 14 patients have been re-assessed and are no longer considered to be 'at-risk' of CJD for public health purposes.

Table 2 Panel advice to inform patients that they are 'at-risk' of CJD/vCJD: 1 January 2000 to 30 June 2006

*The index patient was a blood component recipient with evidence of vCJD infection. Information about the CJD Incidents Panel can be found on the HPA website [3].

The National Anonymous Tonsil Archive
The National Anonymous Tonsil Archive (NATA) is currently receiving approximately 400 tonsil pairs per week from hospitals in England and Scotland . By the end of November 2006, 35,600 tonsil pairs had been collected (figure 1). A further 3000 tonsil pairs from the Medical Research Council Prion Unit, has brought the total number of tonsil pairs in the archive to 38,600. In addition, 1375 collection forms have been completed and returned without accompanying tonsil tissue of which 896 were due to patient objection and 479 specimens having to be retained for analysis as part of the patients' care.

Out of the 100 NHS Hospital Trusts that perform over 200 tonsillectomies per year in England, 88 send tonsil pairs to NATA on a regular basis (figure 2). There are 120 hospitals sites within these trusts taking part in NATA. Approximately 50,000 tonsillectomies are currently performed annually in England.

Scotland; where just over 5000 tonsillectomies are performed each year, joined the project in January 2006. This part of the project is being coordinated by Health Protection Scotland. There are 14 hospitals in Scotland which carry out more than 200 tonsillectomies per year and already 11 of these hospitals have started collecting tonsils for NATA. Tonsil tissue collected in Scotland is being transported to the Health Protection Agency Centre for Infections for inclusion in the archive.

Figure 1 Number of tonsil pairs collected for NATA monthly: January 2004 to November 2006

Figure 2 NHS Trusts in England and hospital sites currently sending tonsils to NATA

®Crown copyright. All rights reserved. HPA, 100016969; (2006).

References
1. The National Creutzfeldt-Jakob Disease Surveillance Unit, The University of Edinburgh. CJD statistics. CJD figures. Edinburgh: NCJDSU, 3 May 2005. Available at <http://www.cjd.ed.ac.uk/figures.htm>.

2.The National Creutzfeldt-Jakob Disease Surveillance Unit, The University of Edinburgh. Incidence of variant Creutzfeldt-Jakob disease onsets and deaths in the UK January 1994 to March 2005. Edinburgh: NCJDSU, 14 April 2005. Available at <http://www.cjd.ed.ac.uk/vcjdqmar05.htm>.

3. Health Protection Agency CJD Incidents Panel. [online]. London: HPA. Available at
<http://www.hpa.org.uk/infections/topics_az/cjd/incidents_panel.htm>.

4. HPA. The National Anonymous Tonsil Archive: a resource for Creutzfeldt-Jakob disease studies. Commun Dis Rep CDR Wkly [serial online] 30 October 2003 [accessed 14 December 2006]; 13(44): News. Available at: <http://www.hpa.org.uk/cdr/archives/2003/cdr4403.pdf>.