Transmissible spongiform encephalopathy agents: safe working
and the prevention of infection. Guidance from the UK Advisory Committee on
Dangerous Pathogens and the Spongiform Encephalopathy Advisory Committee
Revised guidelines have been issued in the United Kingdom
(UK) on reducing the occupational risk of exposure to TSE infectivity (http://www.doh.gov.uk/cjd/tseguidance
The guidance is aimed at employers and others, such as staff working in infection
control and the reprocessing of medical devices. It is also relevant to pathologists
and others handling deceased infected patients and people working with human
and animal TSEs in the laboratory, including those working with diagnostic
specimens (potentially) infected with TSEs.
The guidance was prepared by a Joint TSE Working Group, drawn from members
of the Advisory Committee on Dangerous Pathogens (ACDP, http://www.doh.gov.uk/acdp/)
and the Spongiform Encephalopathy Advisory Committee (SEAC, http://www.seac.gov.uk),
and other experts. Their remit was to consider the risks from exposure to
TSE agents that may arise as a result of work activities, and to provide
advice on the minimisation of such risks and other related matters. This
revised edition has been produced in the light of enhanced scientific knowledge
and the practicalities of working with the 1998 guidance.
The format is the same as the 1998 edition but the document is significantly
expanded and web based with the main changes being:
The risk categorisation of patients (definite, probable
or possible Creutzfeldt-Jakob disease (CJD) and variant Creutzfeldt-Jakob
disease (vCJD) is now based on established, published, diagnostic criteria.
A new category of symptomatic patients 'with neurological
disease of unknown aetiology where the diagnosis of CJD is being actively
considered' has been included to encourage appropriate handling of surgical
instruments, on a precautionary basis, recognising that CJD is sometimes
difficult to diagnose in the early stages of the disease.
A clearer description of the asymptomatic 'at risk'
patient groups, divided into those at risk from familial forms of the
disease and those at risk from iatrogenic exposure.
Abandonment of the earlier recommendation for enhanced
reprocessing of certain surgical instruments in particular circumstances.
The regimen previously recommended is now known not to be reliably effective
and may even render instruments more difficult to decontaminate.
A recommendation to quarantine instruments pending
diagnosis in certain circumstances. This was recommended in a Health Services
Circular issued in 1999. The advice has now been subsumed into this guidance
Extensive scientific information on the distribution
of abnormal prion protein in human tissues and body fluids, which forms
the basis of the guidance.
Extensive cross referencing to other relevant guidance.