Accuracy of a history of blood donation from surrogate witnesses: data from the UK TMER study

Look-back studies of blood transfusion in Creutzfeldt-Jakob disease commonly rely on reported history from surrogate witnesses. Data from the UK Transfusion Medicine Epidemiology Review have been analysed to determine the accuracy of the blood donation history provided by the relatives of cases. Our results show that only a small percentage of cases were found to be registered as donors on UK Blood Service (UKBS) databases when there was no family report of blood donation. In contrast, a history of reported donation was less accurate.

Creutzfeldt-Jakob disease and blood transfusion safety

Transmissible spongiform encephalopathies (TSEs) are untreatable, fatal neurologic diseases affecting mammals. Human disease forms include sporadic, familial and acquired Creutzfeldt-Jakob disease (CJD). While sporadic CJD (sCJD) has been recognized for near on 100 years, variant CJD (vCJD) was first reported in 1996 and is the result of food-borne transmission of the prion of bovine spongiform encephalopathy (BSE, 'mad cow disease'). Currently, 230 vCJD cases have been reported in 12 countries, the majority in the UK (178) and France (27). Animal studies demonstrated highly efficient transmission of natural scrapie and experimental BSE by blood transfusion and fuelled concern that sCJD was potentially transfusion transmissible. No such case has been recorded and case-control evaluations and lookback studies indicate that, if transfusion transmission occurs at all, it is very rare. In contrast, four cases of apparent transfusion transmission of vCJD infectivity have been identified in the UK. Risk minimization strategies in response to the threat of vCJD include leucodepletion, geographically based donor deferrals and deferral of transfusion recipients. A sensitive and specific, high-throughput screening test would provide a potential path to mitigation but despite substantial effort no such test has yet appeared. The initial outbreak of vCJD appears to be over, but concern remains about subsequent waves of disease among those already infected. There is considerable uncertainty about the size of the infected population, and there will be at least a perception of some continuing risk to blood safety. Accordingly, at least some precautionary measures will remain in place and continued surveillance is necessary.

Ten-year follow-up of two cohorts with an increased risk of variant CJD: donors to individuals who later developed variant CJD and other recipients of these at-risk donors

BACKGROUND

Transmission of variant Creutzfeldt-Jakob disease (vCJD) through blood transfusion is implicated in three deaths and one asymptomatic infection. Based on this evidence, individuals assessed to be at increased risk of vCJD through donating blood transfused to individuals who later developed vCJD, or through being other recipients of such donors, are followed up to further understand the risks of vCJD transmission through blood.

OBJECTIVES

To provide a ten-year follow-up of these at-risk cohorts.

METHODS

Blood donors to patients who later died from vCJD were identified by the Transfusion Medicine Epidemiological Review (TMER) study. A reverse risk probability assessment quantified the risk of blood transfusion or exposure through diet as the source of vCJD in the recipients. Donors to these recipients, and these donors' other recipients, with a probability risk above 1%, are classified as at increased risk of vCJD for public health purposes. These cohorts are monitored for any vCJD occurrences.

RESULTS

A total of 112 donors and 33 other recipients of their donated blood have been classified as at increased risk. After 2397 and 492 vCJD-free years of follow-up, respectively, no deaths in either at-risk cohort were of vCJD-related causes.

CONCLUSIONS

The at-risk cohorts have survived disease-free far longer than the estimated incubation time for dietary-acquired vCJD (donors) and transfusion-acquired disease (other recipients). However, due to our still limited understanding of, and a lack of a reliable test for, asymptomatic vCJD infection, public health follow-up is necessary for continued monitoring of at-risk cohorts.

vCJD Donor Notification Exercise: 2005

UK blood services, supported by the Health Protection Agency/Health Protection Scotland, carried out an exercise over the summer of 2005 to notify 110 donors whose blood was transfused to three recipients who later developed vCJD. These donors were to be informed that they were now considered 'at risk of vCJD for public health purposes'. The notification began on 20 July 2005 and was completed (barring follow-up) at the end of the first week of October 2005. Apart from two donors who had died, contact was attempted with all donors, including four who were not currently registered with a GP. The lessons learnt about the conduct of such notification have been reviewed. The limited ad hoc feedback available suggests the process and content of this notification was acceptable to donors and their GPs.

A retrospective case note review of deceased recipients of vCJD-implicated blood transfusions

BACKGROUND

To date, four instances of probable transfusion-transmission of variant Creutzfeldt-Jakob disease (vCJD) infection have been described, and surviving recipients of vCJD-implicated blood components have been informed that they may be 'at risk' of vCJD. Nearly two-thirds of all recipients of vCJD-implicated blood components are deceased, and many died before the vCJD risk was known. The primary aim of this study was to determine retrospectively whether there was evidence that any of the other deceased recipients of vCJD-implicated blood components had any clinical signs or symptoms suggestive of vCJD in life. In addition, pathological material from recipients, stored at the time of surgery or autopsy, was sought to allow testing for evidence of vCJD infection. A secondary aim of the study was to obtain information on invasive healthcare procedures undertaken on recipients following the transfusion to identify the potential for onward transmission of infection.

METHODS

A retrospective review of medical case notes of deceased recipients of vCJD-implicated blood components was carried out, and relevant information was extracted. In cases undergoing post-mortem, details of the findings were obtained.

RESULTS

The medical case notes of 33 (83%) deceased recipients of vCJD-implicated blood components, not already known to be infected with vCJD, were reviewed. The median age of recipients was 68 years (interquartile range 57-79 years). Almost half (16) were male. The median time from transfusion to death was 175 days (interquartile range 43-701 days). Most (66%) recipients died in hospital. None of the recipients had documented evidence of clinical signs or symptoms suggestive of vCJD. Only two recipients, both of whom died within a year of transfusion, underwent autopsy examination. Neither brain nor peripheral lymphoreticular tissue was available from either recipient, and pathological material was unavailable from any of the other deceased recipients. Almost half of all recipients underwent at least one invasive healthcare procedure post-transfusion.

CONCLUSIONS

A retrospective review of the medical case notes of the deceased recipients of vCJD-implicated blood components found no evidence that any further cases expressed clinical signs or symptoms suggestive of vCJD during life, but only four of the recipients survived for more than 5 years post-transfusion.

HIV screening reactivity due to donor participation in HIV vaccine trials

We report two instances of human immunodeficiency virus (HIV) serological screening reactivity in blood donations which were subsequently determined to be due to donor participation in HIV vaccine trials. Both donations were screen reactive with atypical patterns on confirmation; no definitive conclusion could be given for either donor. Subsequent questioning identified that both donors had been involved in HIV vaccine trials. In both cases the screening and confirmation identified the presence of HIV antibodies, although vaccine induced. While clinical trials of vaccines are important, the implications of some need careful consideration if they are not to adversely impact other areas of healthcare.

Creutzfeldt-Jakob disease and blood transfusion: results of the UK Transfusion Medicine Epidemiological Review study

BACKGROUND AND OBJECTIVES

This paper reports the results to 1 March 2006 of an ongoing UK study, the Transfusion Medicine Epidemiological Review (TMER), by the National CJD Surveillance Unit (NCJDSU) and the UK Blood Services (UKBS) to determine whether there is any evidence that Creutzfeldt-Jakob disease (CJD), including sporadic CJD (sCJD), familial CJD (fCJD), and variant CJD (vCJD) is transmissible via blood transfusion.

MATERIALS AND METHODS

Sporadic CJD and fCJD cases with a history of blood donation or transfusion are notified to UKBS. All vCJD cases aged > 17 years are notified to UKBS on diagnosis. A search for donation records is instigated and the fate of all donations is identified by lookback. For cases with a history of blood transfusion, hospital and UKBS records are searched to identify blood donors. Details of identified recipients and donors are checked against the NCJDSU register to establish if there are any matches.

RESULTS

CJD cases with donation history: 18/31 vCJD, 3/93 sCJD, and 3/5 fCJD cases reported as blood donors were confirmed to have donated labile components transfused to 66, 20, and 11 recipients respectively. Two vCJD recipients have appeared on the NCJDSU register as confirmed and probable vCJD cases. The latter developed symptoms of vCJD 6.5 years and 7.8 years respectively after receiving non-leucodepleted red blood cells (RBCs) from two different donors who developed clinical symptoms approximately 40 and 21 months after donating. A third recipient, given RBC donated by a further vCJD case approximately 18 months before onset of clinical symptoms, had abnormal prion protein in lymphoid tissue at post-mortem (5-years post-transfusion) but had no clinical symptoms of vCJD. CJD cases with history of transfusion: Hospital records for 7/11 vCJD and 7/52 sCJD cases included a history of transfusion of labile blood components donated by 125 and 24 donors respectively. Two recipients who developed vCJD were linked to donors who had already appeared on the NCJDSU register as vCJD cases (see above). No further links were established.

CONCLUSION

This study has identified three instances of probable transfusion transmission of vCJD infection, including two confirmed clinical cases and one pre- or sub-clinical infection. This study has not provided evidence, to date, of transmission of sCJD or fCJD by blood transfusion, but data on these forms of diseases are limited.

Documented cases of post-transfusion malaria occurring in England: a review in relation to current and proposed donor-selection guidelines

BACKGROUND AND OBJECTIVES

Although uncommon, five cases of transfusion-transmitted malaria have been documented in England over the last 20 years. With the reappearance onto the market of high-quality malaria antibody assays, and by utilizing the results of analysis of these five cases, it has been possible to review the donor malaria-deferral guidelines.

MATERIALS AND METHODS

Details of the five cases of post-transfusion malaria were reviewed against the proposed new donor-deferral guidelines for malaria.

RESULTS

Three of the five cases of post-transfusion malaria were directly attributable to the deferral guidelines, allowing infectious donors to be bled.

CONCLUSIONS

The proposed new guidelines will prevent further cases of transmission from semi-immune individuals.

Use of red cells preserved in extended storage media for exchange transfusion in anti-k haemolytic disease of the newborn

Anti-k is a Kell-related antibody. There is little correlation between the maternal antibody titre and the severity of haemolytic disease of the foetus and newborn, and anaemia is usually associated with low bilirubin levels. Severe erythroblastosis has been reported with a low titre anti-k (IAT 8-16). We report a case of severe haemolytic disease of the newborn (HDN) due to anti-k. HDN was associated with a normal bilirubin level and reticulocytopenia. The foetus was monitored by ultrasound, and delivery by elective caesarean section (CS) was planned. The mother was admitted 1 week before the expected date of delivery, and the infant was delivered by urgent CS. The infant required exchange transfusion. As suitable plasma-reduced (k antigen(-)) red cell units were not readily available, k- SAGM red cell units (preserved in extended storage media: SAGM sodium chloride, adenine, glucose and mannitol) were provided. The post-transfusion Hb remained stable, and the infant did not require further transfusion support. Our findings (reticulocytopenia and normal bilirubin levels) support the hypothesis that the pathogenesis of anaemia and haemolysis in anti-k HDN may be similar to that in anti-K (suppression of erythropoesis and immune destruction of K+ erythroid progenitor cells by macrophages in the foetal liver). The ideal product for exchange transfusion is plasma-reduced RBC, less than 5-days old. We provided a 4-day-old SAGM red cell unit for exchange transfusion in a term infant, and this was uneventful. Caution should be taken, however, and renal function and electrolyte levels should be monitored closely. More information is required regarding the safety of SAGM units for exchange transfusion.

Possible transmission of variant Creutzfeldt-Jakob disease by blood transfusion

BACKGROUND

Variant Creutzfeldt-Jakob disease (vCJD) is a novel human prion disease caused by infection with the agent of bovine spongiform encephalopathy (BSE). Epidemiological evidence does not suggest that sporadic CJD is transmitted from person to person via blood transfusion, but this evidence may not apply to vCJD. We aimed to identify whether vCJD is transmissible through blood transfusion.

METHODS

The national CJD surveillance unit reported all cases of probable or definite vCJD to the UK blood services, which searched for donation records at blood centres and hospitals. Information on named recipients and donors was provided to the surveillance unit to establish if any matches existed between recipients or donors and the database of cases of vCJD. Recipients were also flagged at the UK Office of National Statistics to establish date and cause of death.

FINDINGS

48 individuals were identified as having received a labile blood component from a total of 15 donors who later became vCJD cases and appeared on the surveillance unit's register. One of these recipients was identified as developing symptoms of vCJD 6.5 years after receiving a transfusion of red cells donated by an individual 3.5 years before the donor developed symptoms of vCJD.

INTERPRETATION

Our findings raise the possibility that this infection was transfusion transmitted. Infection in the recipient could have been due to past dietary exposure to the BSE agent. However, the age of the patient was well beyond that of most vCJD cases, and the chance of observing a case of vCJD in a recipient in the absence of transfusion transmitted infection is about 1 in 15000 to 1 in 30000.

Review of counselling in a transfusion service: the London (UK) experience

Donor (and recipient) counselling within the Transfusion Service in the UK has grown in volume and complexity over the last 10 years. The addition of new tests for donated blood and the growth of bone marrow transplantation have increased the demands on counselling staff. New initiatives, such as the HCV look-back programme, have required an extension of the skills and knowledge of staff involved in counselling.

Evaluation of a malaria antibody ELISA and its value in reducing potential wastage of red cell donations from blood donors exposed to malaria, with a note on a case of transfusion-transmitted malaria

BACKGROUND AND OBJECTIVES

Blood donations are often wasted for lack of a satisfactory procedure to evaluate donors potentially exposed to malaria.

MATERIALS AND METHODS

We evaluated a commercial ELISA for the detection of antibodies to malaria and compared it with an immunofluorescent antibody test (IFAT).

RESULTS

When 5,311 sera from routine non-exposed donors were tested, 24 (0.45%) were positive by the ELISA, using a Plasmodium falciparum antigen. Seventeen were subjected to confirmatory testing but none were positive by IFAT. Of 1,000 donors potentially exposed in endemic areas 15 (1.5%) were repeatably reactive by ELISA. 10 of these were tested by IFAT and 2 were positive. When 150 patients attending the Hospital for Tropical Diseases in London with acute malaria were tested, 73% of those infected with P. falciparum were repeatably reactive for malarial antibodies by ELISA and 56% with Plasmodium vivax. Of 88 stored clinical sera tested by both IFAT and ELISA 56 were positive by IFAT and of these 52 (93 degrees/0) were positive by ELISA.

CONCLUSION

The ELISA is sufficiently sensitive and specific to screen at-risk donors. Its use could safely retrieve 40,000 red cell units currently discarded each year in Great Britain.

Evidence that anti-HBc but not HBV DNA testing may prevent some HBV transmission by transfusion

Blood donor screening for antibody to hepatitis B core antigen (anti-HBc) implemented in some countries as a surrogate marker for non-A, non-B hepatitis has been superseded by anti-HCV screening. To assess the value of anti-HBc screening for the detection of hepatitis B surface antigen-negative blood donations that might contain infectious HBV, HBV genomic detection and recipient testing were used. Blood donations were screened and confirmed by multiple anti-HBc assays. Donations containing isolated anti-HBc and those with anti-hepatitis B surface antigen (anti-HBs) level < 0.1 IU/ml were tested for the presence of HBV DNA. Recipients of previous donations from the corresponding donors during the previous 5 years were traced and tested for markers of HBV infection. Of 103 869 donations screened, 586 (0.56%) were anti-HBc positive, two of which contained HBsAg, and 413 (0.4%) had protective (>/= 0.1 IU/ml) levels of anti-HBs. Anti-HBs < 0.1 IU/ml was found in 102 of these donations (0.1%) and isolated anti-HBc in 69 (0.07%). No donations with isolated anti-HBc were HBV DNA confirmed positive. Of 278 recipients of previous donations from 171 donors at risk of HBV carriage, 12 had markers of HBV infection. Six recipients had other identified risk factors. An association with blood transfusion was considered probable in two and possible in four recipients. None of the six corresponding donors had detectable HBV DNA 6-40 months after the implicated donation. The frequency of HBV transmission by chronic carriers negative for hepatitis B surface antigen was estimated in this study to be 1 in 52,000 donations (CI 0.3-7.8/100,000) from HBsAg-negative donors. Such HBV infectious donations may not be detected by DNA amplification.

Fatal Clostridium perfringens sepsis from a pooled platelet transfusion

A male patient with acute myeloid leukaemia received a pooled platelet preparation prepared by Optipress system on the last day of its shelf life. The patient collapsed after two-thirds of the contents had been transfused. Clostridium perfringens was isolated from the platelet bag within 18 h of the acute event. Metronidazole, gentamicin and Clostridium antiserum were then administered in addition to the broad spectrum antibiotics started previously. However, the patient died 4 days after the platelets were transfused. The cause of death was given as cardiovascular shock, entirely compatible with an overwhelming bacteraemic and septic episode. A coroner's verdict of accidental death due to transfusion of a contaminated unit of platelets was recorded. On subsequent investigation Cl. perfringens type A serotype PS68,PS80 (identical to that found in the platelet bag) was cultured from the venepuncture site of the arm of one of the donors who contributed towards the platelet pool. The donor had two young children and frequently changed nappies. Faecal contamination of the venepuncture site was the suspected source for the transmission of Cl. perfringens, an organism commonly found in the soil and intestinal tract of humans. This case dramatically highlights the consequences of transfusing a bacterially contaminated unit. It is vital that such incidents are investigated and reported so that the extent of transfusion-associated bacterial transmission can be monitored and preventative measures taken if possible.

Does anti-HBc reactivity reflect 'lifestyle' risk in north London blood donors?

BACKGROUND AND OBJECTIVES

To determine whether antibody to hepatitis B core (anti-HBc) reactivity, as a marker of hepatitis B virus infection, reflects a 'lifestyle' risk in donors in North London, we have obtained detailed histories from donors with various manifestations of HBV infection.

MATERIALS AND METHODS

Interviews based on a standardised questionnaire were conducted with 70 donors confirmed to be anti-HBc reactive.

RESULTS

Comparison with controls (known to be anti-HBc-negative) and donors reactive for anti-hepatitis-C virus showed that current donor strategies are effective; in our area, reactivity for anti-HBc is not associated with a lifestyle risk for those donors who are unreactive in current mandatory screening tests.

CONCLUSIONS

Blood from donors positive for both anti-HBc and anti-HBs should be considered suitable for transfusion purposes. This is consistent with the practice of accepting blood from naturally immune donors for preparation of hepatitis B immunoglobulin.

Yersinia enterocolitica transmission from a red cell unit 34 days old

In 1993 the North London Blood Transfusion Centre received its first report of Yersinia enterocolitica transmission from a unit of red cells supplied to a local hospital. The recipient was a 23-year-old male who was neutropenic following a third cycle of chemotherapy for treatment of acute myeloblastic leukaemia (FAB type M6) and received a 34-day-old red cell unit. During transfusion the patient developed septicaemia and endotoxin-mediated shock. The transfusion was stopped immediately and broad spectrum antibiotics administered immediately on suspicion of bacteraemia from the transfused unit. This prompt action undoubtedly prevented a fatal outcome. Y. enterocolitica was isolated from the blood bag. Antibody was also detected in the bag and in a sample taken from the donor 39 days post-donation. Antibody to serotype 03 was identified, the commonest serotype reported in transfusion-transmitted Y. enterocolitica. The donor reported no gastrointestinal upset or illness prior to donation. This transfusion reaction might not have occurred had the red cells been transfused earlier in their storage period, but would not have been prevented by the exclusion of donors with a history of gastrointestinal illness as the donor was asymptomatic. Nor would it have been prevented by inspecting the blood for a change in colour, as no such change was observed. Y. enterocolitica is a significant problem in transfusion medicine and transmission is generally associated with a high mortality rate. Hospitals should be urged to investigate bacteriologically all appropriate transfusion reactions so that the true extent of the problem in the United Kingdom can be assessed.

Organisation of blood transfusion services

Worldwide, the availability of blood product support for patients varies considerably, not only in quantity and in standards but also with regard to safety from infections, and specifications for components. Similarly, the organisation responsible for providing blood varies from one country to another. This article discusses the organisation of transfusion services in the UK, describing how the blood supply is provided and looks briefly at the structure of the organisations involved.

Confidential unit exclusion: the North London Blood Transfusion Centre's experience

A 'Confidential AIDS Questionnaire' has been used at North London Blood Transfusion Centre (NLBTC) donor sessions since July, 1985. The aim of the questionnaire is to encourage self-exclusion by those donors whose behaviour puts them at risk of HIV infection. In a situation where such individuals cannot avoid donating they can indicate, in confidence, that their blood should not be used for transfusion. Since the introduction of this procedure, an average of 10 donors per month, who admitted relevant risk behaviour, have been permanently excluded and a number of prospective donors have excluded themselves when faced with the questionnaire. We have found the questionnaire to be well accepted by donors. It is a useful adjunct to routine donor selection and microbiological testing of donations in our efforts to minimize transfusion-transmitted infection.

Visceral leishmaniasis after cardiac surgery

An English child developed visceral leishmaniasis (kala-azar) after cardiac surgery. Neither he nor his mother had ever been out of the UK, and his disease was probably transmitted by blood transfusion. Kala-azar should be considered in patients with unexplained fever and hepatosplenomegaly, even if there is no history of foreign travel.

A study of anti-hepatitis C positive blood donors: the first year of screening

In the U.K., blood donations have been routinely screened for anti-HCV since September 1991. In order to get the most epidemiological benefit from these extensive screening data, the histories obtained at counselling from donors confirmed to be anti-HCV positive, 'indeterminate' and falsely positive have been analysed in detail. In addition, the associations with potential risk factors have been investigated by comparing these groups of donors with a control group of 771 routine donors bled on one day during the study, at North London Blood Transfusion Centre. This paper documents the prevalence and demography of HCV infection in asymptomatic blood donors, to assess various possible sources of infection and the association between liver function test results and alcohol consumption in donors. One in 1400 previously untested donors was confirmed positive for anti-HCV. Age (the group 30-49 years being highest), tattooing and intravenous drug use in both sexes, ear-piercing in males and blood transfusion in females were all significantly associated with an increased risk of HCV infection. Intravenous drug use proved to be the factor most strongly associated with risk. Liver function tests (alanine aminotransferase) were elevated in a significant number of donors confirmed to be anti-HCV positive but no clear correlation between alanine aminotransferase level and either time since infection or alcohol consumption was found. Alcohol consumption was significantly higher in donors confirmed to be anti-HCV positive and was particularly marked in those admitting to previous intravenous drug use.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody to hepatitis C virus in blood donors found positive for other agents. II. Anti-HIV-1

Stored serum samples from 24 blood donors confirmed positive for anti-HIV-1 were tested for antibody to hepatitis C virus (HCV). Those repeatedly reactive using the anti-HCV ELISA screening test were retested by the HCV recombinant immunoblot (RIBA). Risk-factors for the contraction of HIV infection that had been elicited at formal counselling sessions were evaluated in relation to HCV/HIV modes of infection. The only two donors confirmed to be anti-HCV positive both admitted to intravenous drug use.

ABC of transfusion. Massive blood transfusion

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ABC of transfusion. The blood donor and tests on donor blood

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