23 September 2004
Variant Creutzfeldt-Jakob disease and plasma products: implementation
of public health precautions in the UK
Anna Molesworth (email@example.com),
Helen Janecek, Noel Gill, Nicky Connor, Health Protection Agency Communicable
Disease Surveillance Centre, London, United Kingdom
The CJD Incidents Panel (CJDIP), a United Kingdom expert
committee set up to advise on the management of ‘incidents’ of potential transmission
of Creutzfeldt-Jakob disease) between patients, has issued recommendations
on the management of variant CJD (vCJD) risk from implicated plasma products.
To date, nine UK plasma donors are known to have developed vCJD. Collectively,
they made 23 plasma donations. The donated plasma was used to manufacture
factor VIII, factor IX, antithrombin, intravenous immunoglobulin G, albumin,
intramuscular human normal immunoglobulin, and anti-D.
The potential risk of vCJD infection following treatment with any implicated
plasma products, on top of the risk from dietary exposure to the bovine
spongiform encephalopathy (BSE) agent, is very uncertain. So far, there
are no recorded instances of vCJD being spread through surgery, nor have
there been any cases among recipients of plasma products sourced from individuals
who later developed vCJD. In December 2003, the death from vCJD of a person
some years after receiving a blood transfusion from a donor who had died
of vCJD was announced . In July 2004 a second probable case of transfusion-associated
vCJD infection was identified . These two events have increased concern
about the potential infectivity of blood and plasma products.
Public health precautions against vCJD
The CJDIP now recommends that certain special public health precautions
need to be taken for some recipients of UK sourced plasma products that
were manufactured using donations from individuals who subsequently developed
vCJD. This is in order to reduce any possible risk of iatrogenic transmission
The CJDIP has used a vCJD blood risk assessment (http://www.dnv.com/consulting/news_consulting/RiskofInfectionfromvariantCJDinBlood.asp),
together with information on how the particular batches of plasma products
were manufactured, to assess the potential levels of infection that patients
were exposed to.
The CJDIP advises certain special public health precautions need to be
taken for recipients of UK sourced plasma products who have been exposed
to a 1% or greater potential additional risk of vCJD infection as these
patients could pose a risk to others in defined circumstances. These at
risk patients are asked:
- not to donate blood, organs or tissues,
- to inform their clinician if they need medical, surgical or dental
treatment, so that infection control precautions (http://www.advisorybodies.doh.gov.uk/acdp/tseguidance/)
can be taken to reduce any possible risk of spreading vCJD, and
to consider informing their family, in case they (the patients)
need emergency surgery in the future.
The CJDIP has categorised each batch of implicated plasma products according
to the likelihood that special public health precautions need to be taken
- High: the amount of potential infectivity in
product batches was high enough to warrant special public health
precautions following the administration of a very small dose. These
batches should be traced, and the recipients advised of their exposure
and asked to take special public health precautions.
- Medium: substantial quantities of the material
in question would need to have been administered to warrant special
public health precautions. Efforts should be made to trace these
batches and assess the additional risk to individual recipients
to determine if special precautions should be taken.
- Low: the potential additional risk to recipients
is considered negligible. These batches do not need to be traced
and the individual recipients do not need to be informed.
This categorisation is based on very cautious assumptions, and the uncertainties
underlying the assessment of ‘risk’ are great. The CJDIP guidance is to
limit any possible iatrogenic human-to-human transmission of vCJD. It should
NOT be interpreted as an estimate of an individual patient’s
additional risk of developing vCJD, which is uncertain, and likely to be
The patients who may be affected include some patients with bleeding disorders,
some patients with primary immunodeficiency (PID), and some patients with
other conditions, who may include, for example, patients with secondary
immunodeficiencies, certain neurological and autoimmune conditions, plasma
exchange recipients and patients with severe burns, and with some other
conditions requiring critical care.
Patients in the UK who are ‘at-risk’ of vCJD for public health purposes
are being contacted by their doctors and informed of the precautions they
will need to take.
The product manufacturers are providing details to individual countries
to which parts of batches with a ‘High’ or ‘Medium’ likelihood that public
health precautions might be required were exported. The UK Department of
Health and the Health Protection Agency are providing further details to
authoritative bodies in these countries as well as to the European Commission
The Health Protection Agency’s (HPA) CJD section at the Communicable Disease
Surveillance Centre is coordinating the patient notification in England,
Wales, and Northern Ireland. The Scottish Centre for Infection and Environmental
Health (SCIEH) is coordinating this notification in Scotland. Background
information about vCJD with useful links is available from their websites:
*Editorial note, 24 September 2004: the second paragraph
of this report has been re-edited for grammatical corrections since publication.
- Llewelyn CA, Hewitt PE, Knight RS, Amar K, Cousens S, Mackenzie J, et
al. Possible transmission of variant Creutzfeldt-Jakob disease by blood
transfusion. Lancet 2004;363(9407):417-21.
- Peden AH, Head MW, Ritchie DL, Bell JE, Ironside JW. Preclinical vCJD
after blood transfusion in a PRNP codon 129 heterozygous patient. Lancet
back to top