After the storm? UK blood safety and the risk of variant Creutzfeldt-Jakob Disease - Science and Technology Committee Contents


2  Current infection risk and mitigation

The UK blood supply

7. Across the UK, blood donation and transfusion is made possible by one of four devolved Blood Services, each accountable to its own Department of Health: NHS Blood and Transplant (serving England and North Wales), the Welsh Blood Service, the Scottish National Blood Transfusion Service and the Northern Ireland Blood Transfusion Service.[14] Sensibly, despite this devolved structure, policies governing donor selection, testing and manufacturing are UK-wide, with recommendations provided by a variety of scientific advisory bodies, including:

·  The Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO), an independent scientific advisory committee[15] (SAC) responsible for advising "UK ministers and health departments on the most appropriate ways to ensure the safety of blood, cells, tissues and organs for transfusion/transplantation";[16]

·  The Advisory Committee on Dangerous Pathogens, an SAC responsible for providing "scientific advice on the risks to exposure to pathogens and risk assessment advice on transmissible spongiform encephalopathies" such as CJD and vCJD;[17]

·  The National Expert Panel on New and Emerging Infections, an SAC which "assesses the threat from new and emerging infectious diseases" and advises the Government on prevention and control measures;[18] and

·  The UK Blood Services Joint Professional Advisory Committee, a coordinating body which provides advice across UK Blood Services to ensure that the UK has "a common set of guidelines for blood transfusion services".[19]

8. In recent years, the UK has maintained a strong blood safety record and the likelihood of a patient suffering harm as a result of an infection transmitted through donated blood is extremely low.[20] According to Dr Paula Bolton-Maggs, Medical Director of the Serious Hazards of Transfusion (SHOT) scheme, a professionally-led blood safety monitoring system, recent UK figures for transfusion-transmitted infections compare favourably with previous periods and UK blood safety is currently "equivalent [to], if not better" than that of other developed countries.[21] However, cases do continue to occur. In 2012, the SHOT scheme recorded three instances of transfusion-transmitted infection, all of which caused "major morbidity".[22] Some witnesses saw such cases as evidence that UK defences against blood-borne pathogens remained fallible, surmising that the UK blood supply was still not as safe as it reasonably could be.[23]

9. Blood transfusions save lives and we should be proud, as a nation, of our long tradition of altruistic donation. In recent years, the UK blood supply has proved to be extremely safe and, in the vast majority of cases, the benefits of receiving a transfusion will far outweigh the risk of acquiring a transfusion-transmitted infection. However, we urge against complacency and stress the need for UK Blood Services to remain vigilant to the threat posed by blood-borne pathogens.

In the following paragraphs we consider some of the key risks facing the UK blood supply and the measures in place to mitigate them.

RISKS TO THE UK BLOOD SUPPLY

10. Transfusion-transmitted infection risks can be divided into three categories:

i)  Known risks that can be well mitigated;

ii)  Known risks that cannot be well mitigated; and

iii)  Unknown risks.

Viruses and bacteria, the pathogens responsible for most common infectious diseases, make up the bulk of the first category. The second category is currently dominated by a more unusual type of infectious agent known as a prion, the biology of which is discussed briefly below. The composition of the third category is, by definition, unknown, but could feasibly include all of the above and potentially other, as yet unidentified, types of pathogen.

Known risks that can be well mitigated

11. Existing blood safety measures are largely focused on mitigating the known risks posed by certain well-characterised pathogens. These currently include a wide range of bacteria, viruses and parasites, including hepatitis B and C, HIV, syphilis and the micro-organisms responsible for malaria and Chagas' disease.[24] Of course, these pathogens were themselves once unknown; a blood safety strategy based on known risks is therefore largely retrospective, with risk mitigation measures only being implemented once a pathogen has been identified as a threat, often through instances of transfusion-transmitted infection. Current measures to protect the blood supply from hepatitis C and HIV, for example, were only implemented after the mass infection events of the 1970s, 80s and 90s.[25]

Known risks that cannot be well mitigated

12. In most cases, once a pathogen has been identified as a potential threat, it is possible to put measures in place to prevent that threat from being realised. However, some pathogens are invulnerable to standard risk mitigation measures and may therefore continue to pose a threat even after they have been identified. The most noteworthy type of pathogen currently in this category is the prion.[26]

13. A prion is an infectious agent comprised of protein folded into an abnormal form. Unlike other pathogens, prions contain no genetic material and closely resemble naturally occurring proteins, making them extremely difficult to detect, remove or selectively inactivate.[27] As a consequence, prions are largely invulnerable to many of the methods used to mitigate the risk posed by other known pathogens. Prions are responsible for a family of fatal brain diseases known as transmissible spongiform encephalopathies (TSEs). Examples include livestock diseases such as bovine spongiform encephalopathy (BSE) and scrapie[28] and, in humans, Creutzfeldt-Jakob Disease (CJD), a debilitating disease caused by a build-up of abnormal protein in the brain. Symptoms of CJD are similar to those of dementia and include loss of balance, coordination and mobility, loss of memory, slurred speech, personality change and progressive loss of brain function. CJD is invariably fatal and most people die within a year of first experiencing symptoms.[29]

14. Prior to the mid-1990s, three types of "classical" CJD had been characterised:

·  an inherited form that runs in families (typically 5-10 cases per year in the UK);

·  an acquired form, transmitted through contact with human tissue contaminated with prions (2-3 per year), and

·  a sporadic form of unknown cause, historically responsible for the majority of cases (50-100 per year).[30]

Following the BSE epidemic of the late 1980s and early 1990s, the first cases of a new form of CJD were identified. Variant Creutzfeldt-Jakob Disease (vCJD) shared some symptoms with classical CJD but tended to affect younger people and led to a longer period of illness before death.[31] Primary transmission was thought to be caused by exposure to BSE-infected material, such as contaminated meat. Since vCJD was first identified in 1995 it has been attributed to 177 UK deaths, the majority occurring between 1996 and 2003.[32]

15. Secondary transmission of a disease occurs when an individual carrying the infectious agent passes that infection on to another person. This has been demonstrated to occur both in acquired forms of classical CJD, for example through the use of contaminated surgical instruments (see paragraphs 27-29), and in vCJD, which has been shown to have been transmitted via blood transfusion. Dr Lorna Williamson, Medical and Research Director, NHS Blood and Transplant (NHSBT), explained that in the late 1990s and early 2000s:

    three patients developed variant CJD between six and eight years after a blood transfusion, and their donors also went on to develop variant CJD, suggesting that their transfusion may have been the source of the infection. There was a fourth recipient who had no symptoms during life but who at post-mortem showed signs of variant CJD.[33]

According to Dr Simon Mead, Association of British Neurologists, this constitutes "hard evidence that variant CJD has been transmitted [via] blood transfusion".[34] However, the UK Blood Services Prion Working Group stated that there was "considerable uncertainty as to the magnitude of the risk" posed by this mode of transmission: for example, with regard the level of infectivity in blood and the likelihood that infected individuals would go on to develop disease.[35] Nevertheless, several international advisory bodies, including the US Food and Drug Administration, do not recommend that donations be taken from people who spent time in the UK between 1980 and 1996 due to the perceived risk of vCJD.[36]

16. In October 2013, the British Medical Journal published the results of a large study intended to provide further information on the potential public health risk posed by vCJD.[37] The study, led by Public Health England, looked for the presence of prions in 32,441 samples of archived appendix tissue in order to estimate the rate of "subclinical infection": that is, the approximate number of individuals who carry prions—and could potentially transmit them to others—but do not knowingly suffer from prion disease. The study detected the presence of prions in 16 of the samples, suggesting that around 1 in 2,000 people in the UK could be 'silent carriers' of vCJD. The implications of these results remain uncertain. According to Professor Richard Knight, Director of the National CJD Research and Surveillance Unit:

    We do not know for sure whether the appendix data really mean that these people are infected. Even if they do, we do not know whether these people are infectious. If they are infectious, we do not know for what period of time they are infectious, so there is another uncertainty.[38]

Dr Williamson, NHSBT, agreed that there remained "a good deal of uncertainty" about the risk of blood-borne vCJD transmission but stated that it was desirable to "keep and, if possible, improve the preventative steps that we take" to prevent transmission from occurring.[39] Dr Paul Cosford, Medical Director, Public Health England, likewise stated that "the most precautionary steps" needed to be taken in order to minimise risk.[40] The Minister stated that she considered the Government's approach to be "extremely precautionary"; however, several witnesses stated that blood-borne vCJD remained "a concern" and Christine Lord, mother of vCJD victim Andrew Black, called the issue "a ticking health time-bomb, which must be addressed and tackled".[41]

17. The evidence that we have heard suggests that we cannot be confident that prions are not present in the blood supply. There remains considerable uncertainty about the potential implications of such contamination. We consider it imperative that a precautionary approach to this risk be maintained until further evidence becomes available.

Unknown risks

18. According to Dr Matthew Buckland, UK Primary Immunodeficiency Network, while known pathogens such as "the major viruses" continue to cause occasional infections in transfusion patients, "the unknown unknowns are clearly the greater problem […] the things that we yet don't know to worry about".[42] Pathogens are constantly emerging, evolving and colonising new areas and the campaign group TaintedBlood described the UK blood supply as "highly susceptible" to these emerging risks.[43] Other witnesses agreed that emerging pathogens remained an issue.[44] A 2009 study published in the journal Transfusion identified 68 emerging infectious agents that potentially posed a threat to the blood supply. The majority of these risks were not, at the time, mitigated by existing measures.[45] However, Dr Sheila MacLennan, Chair of UK Blood Services Joint Professional Advisory Committee, stressed that one of her group's main responsibilities was to conduct "external horizon scanning" to identify such threats and she added that she personally sat "on a European committee that looks at emerging infectious diseases".[46] Dr Bolton-Maggs, SHOT, also highlighted the "very good" global screening processes in place to identify emerging infections.[47]

RISK MITIGATION MEASURES

19. Several controls are currently in place across UK Blood Services which are designed to mitigate both known and, to an extent, unknown infection risks.

Donor selection

20. Not everyone is accepted as a blood donor. Before making a donation, all potential donors complete a donor questionnaire (or 'health check') during which "a number of confidential questions" are asked in order to establish whether or not that individual meets the selection criteria.[48] These criteria are intended to protect both donor and recipient and include several measures to reduce the likelihood of transfusion-transmitted infections from occurring. For example, people are asked not to donate if they are suffering from a chesty cough, sore throat or active cold-sore, or if they are currently taking antibiotics or have had any infection in the two weeks prior to donation.[49] In addition, according to UK Blood Services' Joint Professional Advisory Committee (JPAC), "as donation testing for infectious agents cannot be 100% effective, it is important to retain policies which defer donors with lifestyle factors which increase infection risk".[50] As such, temporary and, in some cases, permanent deferrals are in place for people participating in certain activities, detailed in table 1.
Behavioural risk Donor deferral period
Accepting money or drugs for sex Permanent
Intravenous drug use Permanent
Sex with a sex worker 1 year from last sexual contact
Sex with an intravenous drug user 1 year from last sexual contact
Sex with anyone who may ever have had sex in parts of the world where HIV/AIDS is common 1 year from last sexual contact
Sex with anyone infected by HIV, Hepatitis B or C 1 year from last sexual contact
Sex with a man (if the potential donor is male) 1 year from last sexual contact
Sex with a man who has had sex with another man (if the potential donor is female) 1 year from last sexual contact
Sex with anyone with haemophilia or a related blood clotting disorder who has received clotting factor concentrates 1 year from last sexual contact

Table 1: Behavioural deferrals for potential blood donors[51]

21. Witnesses pointed out several weaknesses associated with the use of donor selection as a tool for infection risk mitigation:

·  Reliability of information: Whether errors are accidental or due to deliberate non-compliance, not all of the information provided during donor screening is likely to be accurate. According to the Health Protection Agency (now Public Health England, PHE), in 2011, 290 blood donations tested positive for either hepatitis B, hepatitis C, HIV, HTLV[52] or syphilis. Of these, "11% should not have been made if donors had disclosed relevant information at the time of their donation".[53] The most common reason given for non-compliance was the belief that the information "did not matter".[54] PHE is currently conducting a survey of UK donors in order to better understand compliance levels.[55]

·  Donor pool reduction: Over 10% of attendances at UK blood sessions result in the potential donor being deferred and, according to Dr Sheila MacLennan, JPAC, "about 30% […] do not return".[56] Changes to donor selection policies have led to a reduction in the referral rate in recent years; however, according to Terumo BCT,[57] "the increased use of donor deferrals […] has been a major strand of NHSBT policy" and could lead to a problematic reduction in the size of the donor pool if widespread outbreaks of blood-borne pathogens were to occur in the future.[58]

·  Potential for discrimination: Donor selection policies are currently based on population-level rather than individualised risk factors, leading to potentially inaccurate or even discriminatory assessments being made. Men who have sex with men are currently deferred from donating blood for 12 months following last sexual contact (see table 1);[59] however, as Stonewall pointed out, "gay and bisexual men are not automatically at a higher risk of contracting sexually transmitted infections"—"heterosexual people can engage in risky sexual behaviour too".[60] Stonewall stated that it was "concerned" that "gay and bisexual men engaged in low-risk sexual activity" were excluded from giving blood "while heterosexual people engaged in higher risk activity" were not.[61] Professor Mark Turner, Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO), agreed that individualised risk assessment was "an ideal" but stated that there were "practical problems and issues" that would need to be resolved before this could be implemented.[62]

22. We echo concerns that population-level risk assessment could lead to inaccurate and potentially discriminatory judgements being made about the risk posed by individuals, particularly men who have sex with men. We recommend that the Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) reconsider the feasibility of a move to more individualised risk assessment as part of its 2015 work programme, following completion of the current UK blood donor survey.

Blood sample testing

23. According to the Government, "all blood donations are tested on every occasion" for evidence of infection with five known pathogens:

·  human immunodeficiency virus (HIV);

·  hepatitis B virus;

·  hepatitis C virus;

·  human T-cell lymphotropic virus (HTLV); and

·  syphilis.[63]

In addition, "donors who may have been exposed to certain infections found outside the UK", that is, malaria and Chagas' disease[64], "undergo specific testing before their blood is released for use".[65] In 2011, of the 2.4 million donations tested throughout the UK, 290 (0.012%) tested positive for one of the five infections universally screened for.[66] Of the 44,103 donations tested for malaria, 1,495 (3.4%) were positive.[67] Tests for cytomegalovirus (CMV)[68] are also carried out on a subset of donations "to meet the specific clinical needs of patients with depressed immunity".[69]

Leucodepletion

24. Leucodepletion is the process by which white blood cells are removed from whole blood, usually through use of a specialised filter. It confers several benefits on recipients[70] but was initially implemented in 1999 because of its presumed ability to reduce the risk of prion transmission. The lack of confirmed cases of transfusion-transmitted vCJD since 1999 has led the Advisory Committee on Dangerous Pathogens to speculate that leucodepletion "may have had a substantial impact on blood-borne transmission risks" and witnesses praised the Government's "prescient" decision to introduce this measure at a time when the prevailing scientific view was that blood transfusion would not prove to be a source of prion transmission.[71] However, for many years leucodepletion's utility as a vCJD risk reduction measure was unconfirmed and Dr Williamson, NHSBT, stated that the measure's "high effectiveness" in removing prions had only recently been established.[72] Chief Medical Officer Dame Sally Davies stated that leucodepletion "probably" removed "about 40%" of prion infectivity, at an estimated cost, according to Dr Williamson, of "£4 million to £4.5 million per year".[73]

Other pathogen reduction steps

25. In addition to leucodepletion, additional "pathogen reduction" measures may be applied to certain blood components to further reduce the risk of transfusion-transmitted infection, including of unknown pathogens. Nigel Talboys, Director of Blood Safety at Terumo BCT,[74] explained the advantages of this approach:

    Many new pathogens come along. One of the issues is: can you test for every single one? The answer to that is, probably, no. By implementing a pathogen-reduction technology, you are able to inactivate not only the known pathogens […] but also give a level of protection against those emerging or unknown pathogens.[75]

Plasma imported for UK use is currently treated with methylene blue which, according to Professor Turner, SaBTO, "will inactivate most, [but] not all, bacteria and viruses".[76] Professor Turner acknowledged, however, that "the vast majority of blood components" do not currently undergo such pathogen reduction measures as there are "currently no licensed pathogen inactivation systems" that can be used on whole blood.[77] In December 2013, SaBTO recommended that novel technologies for pathogen reduction in platelets should not be implemented, in part because of their poor cost-effectiveness.[78]

26. Pathogens are constantly emerging and evolving; novel pathogens will therefore always pose a threat to the blood supply. In the past, it has often taken multiple cases of transfusion-transmitted infection before these threats have been recognised and mitigated. This will remain the case as long as risk mitigation measures remain pathogen-specific. We urge the Government to take steps to support the development of broader spectrum technologies with the potential to mitigate the risk of both known and unknown pathogens.

Surgical transmission of prions

27. Blood transfusions are not the only source of secondary prion infection; transmission can also occur via other forms of medical intervention, notably surgery. The prions thought to be responsible for both classical and variant forms of CJD are known to be present in parts of the body that are accessed during surgical procedures.[79] According to Professor John Collinge, MRC Prion Unit, prions are known to "stick very avidly to metal surfaces", meaning that contaminated surgical instruments could potentially act as "a very efficient route" of person-to-person prion transmission.[80] This is more than just a theoretical risk: Professor Richard Knight, Director of the National CJD Research and Surveillance Unit, confirmed that "a handful" of cases of classical CJD appeared to have been transmitted in this way.[81] Professor Collinge added that there was "epidemiological evidence from several countries now that patients developing classical CJD are more likely to have had abdominal surgery beforehand", suggesting a potential link between the procedure and the disease.[82] Professor Collinge also considered it possible that some cases of vCJD had "been related to" surgical exposure, but members of the Department of Health's Decontamination Science Working Group stated that these concerns were "exaggerated".[83] To date, there have been no cases in which it has been conclusively demonstrated that vCJD has been transmitted via surgery, although scientific evidence suggests that this would be possible. [84]

28. Speaking on behalf of the Government, Chief Medical Officer Dame Sally Davies, stated that she was "concerned about the transmission of disease" via surgical instruments and claimed that the Government had applied the precautionary principle in its management of this risk.[85] The Government highlighted two key steps that it had taken:

·  Since the mid-1990s, the Advisory Committee on Dangerous Pathogens (ACDP) has issued guidance on "the decontamination, quarantining and appropriate use of surgical equipment (including endoscopes), and on pre-surgical assessment of patients to identify and act on those with, or at risk of, all forms of human prion disease".[86]

·  In 2006, the National Institute for Health and Care Excellence (NICE) issued guidance on "patient safety and reduction of risk of transmission" of CJD via surgical procedures.[87] This made several suggestions relating to the management and tracking of surgical instruments and recommended the use of new, unused instruments for certain groups, such as children undergoing high-risk procedures.

We did not receive any evidence on current levels of compliance with the ACDP guidance but, according to NICE, following publication of its 2006 guidance, the Department of Health became aware that implementation "had not proceeded satisfactorily".[88] A number of activities took place to address this and in 2008 NICE published additional resources to aid implementation, including "a checklist for acute Trusts to self-assess current practice against the guidance".[89] NICE does not perform implementation audits for this type of guidance. However, a 2011 academic study examining decontamination procedures across a sample of NHS centres found that the guidance had only been "fully implemented" in ten (19%) of the organisations audited.[90] Dame Sally stressed the importance of NICE's "significant" guidance and stated that she was "not aware" that it had not been fully implemented and would consider it "unacceptable" if this were the case.[91]

29. The Government has acknowledged that contaminated surgical instruments are a potential source of prion transmission and states that it has taken a precautionary approach in its response to this risk. However, this response appears to rest heavily on guidance which, based on the available evidence, may not have been fully implemented. We recommend that the Government work with the National Institute of Health and Care Excellence (NICE) and the Advisory Committee on Dangerous Pathogens to better understand the extent to which the precautions recommended by these bodies have been implemented across the NHS. We ask the Government to provide us with an update on this work well before the dissolution of Parliament, together with an indication of the steps it will take if preliminary findings suggest that implementation has been incomplete.


14   BTO30 para 2 [JPAC] Back

15   Government Office for Science's Code of Practice for Scientific Advisory Committees (2011) refers to SACs as "advisory committees providing independent scientific advice, regardless of their specific structure and lines of accountability; whether reporting to a Ministerial Department, Non-Ministerial Department or other public body, and whether an advisory NDPB or an expert scientific committee".  Back

16   Advisory Committee on the Safety of Blood, Tissues and Organs, 'Homepage', Government.uk, accessed 30 June 2014 Back

17   Advisory Committee on Dangerous Pathogens, 'Homepage', Government.uk, accessed 30 June 2014 Back

18   National Expert Panel on New and Emerging Infections, 'Homepage', Government.uk, accessed 30 June 2014 Back

19   Q30 [Dr Sheila MacLennan]; Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee, 'Welcome to JPAC', transfusionguidelines.org.uk, accessed 30 June 2014 Back

20   See, for example, Q146 [Dr Paula Bolton-Maggs] and 'Annual SHOT report 2012', July 2013, accessed 30 June 2014  Back

21   Q146 Back

22   According to the Summary of the 2012 SHOT report (see previous footnote): "A child with sickle cell disease developed proven transfusion-transmitted parvovirus infection. There was a case of hepatitis E transmission [...] and two patients were infected with hepatitis B from a single donor" [counted as a single instance of transfusion-transmitted infection]. Note: the 'Annual SHOT report 2013' was released shortly prior to publication of this Report and is available at shotuk.org. Back

23   See, for example, Q1 [Christine Lord], Q2 [Joseph Peaty], Q2 [Liz Carroll] Back

24   BTO31 para 20 [Government] Back

25   Independent Public Inquiry Report on NHS Supplied Contaminated Blood and Blood Products, 'The Archer Inquiry', February 2009 Back

26   See, for example, Q3 [Dr Matthew Buckland] Back

27   Parliamentary Office of Science and Technology, vCJD in the future, POSTnote number 171, January 2002 Back

28   Scrapie is a transmissible spongiform encephalopathy (TSE) endemic in British sheep and found in many parts of the world. Also found in goats. Symptoms of scrapie include changes in behaviour, changes in posture and movement and skin irritation leading to repeated rubbing and scratching. Back

29   Parliamentary Office of Science and Technology, vCJD in the future, POSTnote number 171, January 2002 Back

30   Parliamentary Office of Science and Technology, vCJD in the future, POSTnote number 171, January 2002; National CJD Research and Surveillance Unit, Creutzfeldt-Jakob Disease in the UK (by calendar year), cjd.ed.ac.uk, accessed 30 June 2014 Back

31   Parliamentary Office of Science and Technology, vCJD in the future, POSTnote number 171, January 2002. Back

32   National CJD Research and Surveillance Unit, Creutzfeldt-Jakob Disease in the UK (by calendar year), cjd.ed.ac.uk, accessed 30 June 2014 Back

33   Q241. In addition, in 2009 a case of presumed transmission was described in a patient with haemophilia who had received batches of Factor VIII prepared from plasma from a donor who subsequently died of vCJD. The patient died of unrelated causes but was found at post mortem to have evidence of vCJD prion accumulation in his spleen. It is unclear whether the vCJD infection arose from transmission from the infected donor, transmission from another batch of UK Factor VIII or oral transmission via the food chain (i.e. through eating BSE-infected meat). See BTO14 para 6 [UKBS Prion Working Group]. Back

34   Q149 Back

35   BTO14 para 20, para 24 [UKBS Prion Working Group] Back

36   See, for example: U.S. Department of Health and Human Services, Food and Drug Administration, Center for Biologics Evaluation and Research, Guidance for Industry: Revised Preventive Measures to Reduce the Possible Risk of Transmission of Creutzfeldt-Jakob Disease (CJD) and Variant Creutzfeldt-Jakob Disease (vCJD) by Blood and Blood Products, May 2010 Back

37   Noel Gill et al, 'Prevalent abnormal prion protein in human appendixes after bovine spongiform encephalopathy epizootic: large scale survey', British Medical Journal, 15 October 2013. BMJ2013;347:f5675 Back

38   Q150 Back

39   Q241 [Dr Lorna Williamson] Back

40   Q241 Back

41   Q295 [Jane Ellison MP]; Q3 [Dr Matthew Buckland]; Q1 [Christine Lord] Back

42   Q3  Back

43   BTO18 para 24 [TaintedBlood] Back

44   See, for example, Q4 [Liz Carroll]; Q142 [Nigel Talboys] Back

45   Stramer et al, Emerging infectious disease agents and their potential threat to transfusion safety, Transfusion, Volume 49, August 2009 supplement. Back

46   Q32 Back

47   Q149 Back

48   NHS Blood and Transplant, 'What happens when I give blood?', blood.co.uk, accessed 30 June 2014 Back

49   NHS Blood and Transplant, 'Who can't give blood?', blood.co.uk, accessed 30 June 2014 Back

50   BTO30 para 10 [JPAC] Back

51   Information taken from Advisory Committee on the Safety of Blood, Tissues and Organs, Donor Selection Criteria Review, April 2011, table 4 (p.34) and NHS Blood and Transplant, 'Who can't give blood?', blood.co.uk, accessed 30 June 2014. Back

52   Human T cell lymphotropic virus, a usually asymptomatic virus endemic in the Caribbean, Japan, South America, and parts of Africa. Back

53   Health Protection Agency/NHS Blood and Transplant, Safe supplies: new horizons, October 2013, p.iii. Note, compliance information was only available for 257 of the 290 positive donations.  Back

54   Health Protection Agency/NHS Blood and Transplant, Safe supplies: new horizons, October 2013, p.11 Back

55   NHS Blood and Transplant, 'UK blood donor survey launched', press release, 1 October 2013 Back

56   Q35; BTO47 [JPAC supplementary] Back

57   Terumo BCT is a developer of pathogen reduction technologies. Back

58   BTO47 [JPAC sup.]; BTO15 para 11 [Terumo BCT] Back

59   NHS Blood and Transplant, 'Who can't give blood?', blood.co.uk, accessed 30 June 2014 Back

60   BTO17 para 6 [Stonewall] Back

61   BTO17 para 3 [Stonewall] Back

62   Q34  Back

63   BTO31 para 20 [Government] Back

64   Chagas' disease is a tropical disease caused by a parasitic protozoan (Trypanosoma cruzi). It is marked by prolonged high fever, edema (excess of fluid) and enlargement of the spleen, liver, and lymph nodes. Back

65   BTO31 para 20 [Government] Back

66   Public Health England, 'Surveillance of Infections in Blood Donors', hpa.org.uk, accessed 29 May 2014 Back

67   Public Health England, 'Surveillance of Infections in Blood Donors', hpa.org.uk, accessed 29 May 2014. No donations were found to be positive for Chagas' disease.  Back

68   Cytomegalovirus (CMV) is a form of herpes virus and is extremely common. It causes few symptoms in most people but can act as an opportunistic infection in immunosuppressed individuals; for example, AIDS patients, people undergoing chemotherapy or those taking immunosuppressive drugs following organ transplant. Back

69   BTO31 para 20 [Government] Back

70   See Q256 [Dr Lorna Williamson] Back

71   BTO31 Annex G [Government]; Q161 [Dr Simon Mead]; BTO14 para 5 [UKBS Prion Working Group]. See also Q161 [Professor Richard Knight].  Back

72   Q250  Back

73   Q325 [Dame Sally Davies]; Q256 [Dr Lorna Williamson] Back

74   Terumo BCT is a developer of pathogen reduction technologies. Back

75   Q140 Back

76   Q40 Back

77   Q46 Back

78   Q257 [Dr Lorna Williamson] Back

79   Oral evidence taken on 27 November 2013, HC (2013-14) 846, Q43 [Professor John Collinge] Back

80   Oral evidence taken on 27 November 2013, HC (2013-14) 846, Q43 [Professor John Collinge] Back

81   Q164 Back

82   Q112 Back

83   Q112 [Professor John Collinge]; BTO20 para 12 [DH DSWG] Back

84   Q164 [Professor Richard Knight]; Q112 [Professor John Collinge] Back

85   Q296 and Q300 [Dame Sally Davies] Back

86   BTO31 para 23 [Government] Back

87   NICE, Patient safety and reduction of risk of transmission of Creutzfeldt-Jakob disease (CJD) via interventional procedures, IPG196, November 2006 Back

88   BTO45 para 9 [NICE] Back

89   BTO45 para 9 [NICE] Back

90   Sjogren, G., Creutzfeldt-Jakob Disease: A study into the changes in surgical instrument decontamination made by decontamination managers following the introduction of NICE interventional procedure guidance 196, 2011. Available at the UHI Millennium Institute or from the Committee on request. Note: this study has not, to our knowledge, been subject to peer-review. Back

91   Q296 Back


 
previous page contents next page


© Parliamentary copyright 2014
Prepared 24 July 2014