ISBT Working Party on Transmissible Diseases: Report on the Workshop ‘Infectious-Disease Testing and Quality Control’

ISBT/ICSH Working Patty

Vox Sanguinis Vox Sang 1996;70:53-60

Cees van der Poel a

John Barbara

a Rode Kruis Bloedbank, Utrecht,

ISBT Working Party on Transmissible Diseases: Report on the Workshop ‘Infectious-Disease Testing and Quality Control’

Luc Noel

Roger Dodd

The Netherlands; Centre Transfusion Yvelines, Le Chesnay, France; North London Blood Transfusion Centre, London, UK; American Red Cross, Rockville, Md., USA

This publication reports on a workshop designed to com- pare and contrast regulations, policies, practice and quality control (QC) in infectious-disease testing of blood donors in different countries. It is not intended to be comprehensive. This informal workshop was conducted on July 3, 1994, at the 13th Congress of the International Society of Blood Transfusion (ISBT) in Amsterdam, The Netherlands, and was attended by 41 participants and invitees, representing 26 countries.

Methods

Three months before the workshop, questionnaires were sent by telefax to a selection of 42 individuals from 28 countries, known for their expertise in the field of infectious-disease testing of blood donors and related national and local regulations. The questionnaires con- tained 39 questions directed at the following subject areas: (1) mandatory donor screening tests; (2) licensing or other approval of donor screening tests; (3) QC programmes on screening tests; (4) quarantine procedures and use of retention samples (serotheques); (5) mandatory confirmatory testing; (6) nature and use of confirmatory test procedures, and (7) QC programmes on confirmatory tests. Completed questionnaires were received by telefax, the data were entered into a PC database, and were also reviewed by a steering committee, to identify issues which were unique or of particular interest. A selection of participants was invited to discuss these issues at the workshop, by presenting an explanation of the procedure and the arguments under- lying the practice.

Meeting participants were provided with draft copies of the overview tables at the workshop. After the workshop, another round of questionnaires was mailed to the participants to permit correction of the overview tables.

A workshop conducted by the Working Party on Transmissible Diseases, July 3,1994. at the 13th ISBT Congress in Amsterdam, The Netherlands

0 1996 S. Karger AG. Basel 0042-900719610701-0053 $10.00/0 KARCER

E-Mail kargeret karger.ch Fax +4161 306 I2 34

Results

A total of 37/42 (88%) completed questionnaires, representing 26/28 (93%) of the invited countries, were received by the steering committee.

Mandatory Screening Tests Table 1 summarizes the requirements for microbiologi-

cal screening tests performed on all blood donations. They are classified, by country, on the basis of the nature and source of the requirement to test. Those defined as ‘mandatory nationally’ (N) are performed by all institutions in the country on the basis of a national government regulation; those defined as ‘mandatory locally’ (L) are required for a limited number of institutions on the basis of regional regulations, or those from one particular organization, such as the Red Cross/Red Crescent, when more than one organization is operating on a national scale. In addition, table 1 summarizes those screening tests ‘under consideration or in discussion’ (C), those ‘performed in addition to guidelines, but not mandatory’ (P), and the screening tests performed either nationally or locally for ‘only on new donors’ (ND) and in other ‘selected cases’ ( S ) .

Licensing or Other Approval of Donor Screening Tests Table2 summarizes the requirements, in terms of ap-

proval or licensing of screening test, classified on the basis of the organization which approves the test kit: A = governmental agencies; B = Red Cross or Red Crescent organizations; C = other non-governmental organisations; D = regional authorities. The requirements for test characteristics are defined as formal ‘licensing’ implying a more or less rigorous evaluative process, a ‘general approval’ of spec-

Cees L. van der Poel, MD, PhD Red Cross Blood Bank Utrecht Rubenslaan 190 NL-3582 JJ Utrecht (The Netherlands)

Received June 30,1995 Accepted: July 10,1995

Table 1. Mandatory screening assays in 26 different countries

HBsAg Anti- Anti- Anti- HIV-Ag Anti- Anti- Anti- Syphilis ALT Anti- Other tests HBc HIV-I HIV-112 HCV HTLV-I HTLV-UII CMV

Austria N Belgium N Denmark N England N Finland P France N Germany N Greece N Ireland N Italy N Luxembourg N Netherlands N Norway N Scotland N Spain N Sweden N Switzerland N

Hungary N USA N Canada N Newzealand N Japan N HongKong N Singapore N SouthAfrica N Brazil N

ND

C

N L, c S

ND C ND C C ND

S N C

N

N

N N C N P N N L, C N N N P N N N N C P N

N N C N N N N N N N P

N N N N P N N N N N P N N N N N N

N N N N N N N N N

C N

C N C

C P

C C c, p N P, L

C

c, s

N N

N P N N N N N N N ND N N ND N

N N N N N N N N N

N S L, c s c s

S P S N L, S N S c s

S N P S

P, s S S

C,P s s s N S

L S L S c L,S

S N S N N

S N S

neopterin: N malaria: S

malaria: S

ASTJyGT: P PCR pools: C

1989-1 991 : two anti-HIV tests

parvovirus: C malaria: S

Chagas: N

N = Mandatory nationally; L = mandatory locally e.g. mandatory for some institutions only; C = being considered on a national scale; P = performed but not mandatory; ND = mandatory only for new donors; S = mandatory only in selected cases (see text).

ified test kits, or a simple ‘definition of the performance characteristics’.

QC Programmes on Screening tests Table 3 summarizes the nature and regulatory status of

QC programmes employed either nationally or locally on donor screening tests. External control samples are classified either as a ‘consistency sample’ to monitor shifts in test performance (for instance signa1:cut-off ratios) or as a ‘go- no-go sample’ in which the external control must give a reactive result in order to validate the test run. External control samples can be used to monitor or validate ‘every run’ (ru) or ‘every batch’ (ba). In addition, self-assessment and/or blind proficiency panels may be available on a national scale to validate the performance of the screening laboratory. As indicated in the table, these panels may be issued by: A = governmental agencies; B = Red Cross or Red Crescent

54 Vox Sang 1996;70:53-60

organisations, or C = other non-governmental organizations. In addition, results of proficiency testing may be collated, and screening laboratories may be audited by these agencies and organizations (table 3). The questionnaire did not inquire whether proficiency testing was used for certification of the screening laboratory.

Quarantine Procedures and Use of Retention Samples (Serotheques) In 1 country, donations are discarded after an initially re-

active screen, in the remaining 25, donations with repeatedly reactive screening test results are discarded, with the ex- ception of minor variations in 2 countries: 1 ’where under certain conditions anti-HBc-reactive units are released after positive test results for anti-HBs, and 1 where units reactive in screening tests for anti-HIV, syphilis and Chagas are released after retesting with another screening test, if the latter

van der PoeVNoeVBarbardDodd

Table 2. Requirements for assays in 26 different countries

screening License General Definition of Remarks certif- approval performance icate characteristics

Austria Belgium Denmark England Finland France Germany Greece Ireland Italy Luxembourg Netherlands Norway Scotland Spain Sweden Switzerland Hungary USA Canada New Zealand

Japan Hong Kong Singapore South Africa Brazil

A

A A

C A B

A Ca Db

A

A C‘ A

B

A A

tests should be ‘suited for the purpose’

tests should be ‘suited for the purpose’

Individual test kits may have to be licensed, may need some other form of general approvial or only the performance characteristics of the employed test systems are defined by regulatory agencies. Regulatory agencies may be governmental (A), Red Cross/Red Crescent agencies (B), other non-governmental agencies (C), or regional authorities (D).

Infectious-Disease Testing and Quality Control

A

A, B

B B

tests approved by the FDA or in Europe

9ests licensed by the FDA (USA) beach institution its makes own selection

is negative. In 6/26 (23%) countries (3 of which require this nationally), new donors are tested but wait 2-13 weeks before being drawn; in 3/26 (12%) countries (nationally required in 2/3), plasma units are kept in quarantine 4- 6 months before distribution. Fifteen of 26 (58%) countries have confidential unit exclusion systems for the donors (nationally required in 7/15), in 19/26 (73%) countries, donor deferral registries are kept (nationally mandated in 7/19), and in 17/26 (69%) countries (nationally mandated in 7/17), a serum sample from each donation is stored for a period ranging from 6 months to indefinitely.

Mandatory Confirmatory Testing Table 4 summarizes the microbiological markers for

which confirmatory testing is mandatory. Regulations are

classified as: ‘national’ i.e. to be fulfilled by all institutions in the country, or ‘local’ i.e. to be fulfilled by a limited number of institutions (including regional regulations and regulations from one particular organization when more than one is operating on a national scale). In addition, confirmatory testing is defined on the basis of its use to (a) notify blood donors and/or (b) to reinstate blood donors if the infection cannot be proven by confirmatory assays (re-entry).

Nature and Use of Confirmatory Test Procedures The questionaire requested information on the nature of

the assays that are generally used in the confirmatory strategy. The specific identity ofthe required tests was not sought, and it should be noted that more than one test may be used to confirm a repeatedly reactive screening test. For confirma-

Vox Sang 1996;7053-60 55

Table 3. Quality assurance programmes for blood donor screening as used in 26 different countries

Con- Go-no-go Proficiency panels Collation of Audit of sistency samplesa QC data screening samplesa laboratories oganisationb markers

Austria Belgium Denmark England Finland France Germany Greece Ireland Italy Luxembourg Netherlands Norway Scotland Spain Sweden Switzerland Hungary USA Canada New Zealand Japan Hong Kong Singapore South Africa Brazil

ru ba ba ruiba

ruiba

ba

ru

ru

ru

ru ruiba

ruiba ru

ru ru ru

ba

ba ba

ru

ru ru

N A ru A, B

A d b a A, C ru C ru C

C

ru ru A ruiba A ruiba C ru A ruiba A ru/ba

C B A

ruF A, C A, B

ru B, C ru ba B ba A, C ru C ru A, C

HIV HbsAg, HIV, HCV, syphilis HIV HbsAg, HIV, syphilis HbsAg, HIV, HCV HIV, HTLV, HbsAg all markers but HIV-Ag

HbsAg, HIV, HCV HbsAg, HIV, syphilis, ALT HbsAg, HIV, HCV HbsAg, HIV, HCV HbsAg, HIV, HCV

all markers but syphilis HbsAg, HIV, HCV, syphilis HbsAg, HIV, HCV, syphilis all markers all markers all markers

all markers HbsAg, HIV HbsAg, HIV, syphilis all markers

A A C B, C A C

C B A A, C B C

B A

A, B, C A, B C

B A A, C A

a ru = Every test run; ba = every batch. A = Governmental agencies; B = Red Cross/Red Crescent agencies; C =other non governmental agencies. FDA allows for invalidation of a negative test result, but not of a positive one.

tion of HBsAg, neutralization or blocking assays are used in 22/26 (85%) countries, combined with PCR in 2/22, and 31 26 countries employ other tests, such as the HBV serolog- ical profile, while 2/26 do not use confirmatory assays. An- ti-HIV is confirmed by immunoblot assays (Western blot with natural and/or recombinant or peptide antigens) in all 26 (100%) countries, with immunofluorescence used to some extent in 2. Algorithms incorporate PCR in 4 (15%) of the countries. Typing for HIV-1 versus HIV-2 is performed in 13/26 (50%) countries. Confirmation of anti-HCV is performed by recombinant/peptide immunoblot in 23/26 (88%) countries, with the addition of PCR in 12/23 (52%); 2 countries note use of PCR, but do not specify other tests and 1 uses other tests (not specified). Confirmation of anti- HTLV-1/11 is performed in 13 countries, using immunoblot

56 Vox Sang 1996;70:53-60

assay (Western blot with natural and/or recombinant or peptide antigens) in all 13, with the addition of PCR in 5/13 (38%). Typing (either sero- or genotyping) for HTLV-I versus HTLV-I1 is performed in 8/13 (61%) countries. A reactive screening test for syphilis is confirmed in 24 countries, using immunofluorescence in 18/24 (75%) and in 6 others, unidentified tests are used.

QC Programmes on Confirmatory Tests It is mandatory to have confirmatory testing performed

by an external reference laboratory in 17/26 (65%) countries, 5 of which require this for all tested markers, and 12/17 specify this requirement for at least some of the markers. In 6 countries, blood facilities have a formal contract with an external reference laboratory; this is mandatory in 3 coun-

van der Poel/NoeI/Barbara/Dodd

Table 4. Mandatory confirmation of reactive screening test results in 26 different countries

HBsAg Anti- Anti- Anti- Anti- Anti- Anti- Syphilis ALT Remarks HBc HIV-1 HIV-1/2 HCV HTLV-I HTLV-YII

Austria Belgium Denmark England Finland France Germany Greece Ireland Italy Luxembourg Netherlands Norway Scotland Spain Sweden Switzerland Hungary USA Canada New Zealand Japan Hong Kong Singapore South Africa Brazil

1,3 1 ,3 2,4 1 L 3 2,4 4 3 4 3 1 4 3 1 4 3 2,4 2,4 294 2,4 Chagas

'anti-HBc titer + anti HBs

Confirmation of reactive screening test results may be mandated nationally ( I , 3) of 'locally' e.g. mandatory only for a limited number of institutions (2,4). Confirmation may be used to notify blood donors ( I , 2) or to allow reinstatement ('re-entry') of screening-test-reactive blood donors with negative or non-specific results in confirmatory assays: 1 = national guidelines donor notification; 2 = local guidelines donor notification; 3 =national guidelines re-entry; 4 =local guidelines re-entry.

tries. Confirmatory tests must be licensed in 17/26 (65%) countries (13/16 by governmental agencies), in 3/26 (12%) countries the confirmatory test kits need general approval, and in 2/26 (8%) countries only the performance characteristics of the confirmatory tests are defined in the regulations. Quality-monitoring samples are included in assay runs in 14/26 (54%) countries, and self-assessment and/or blind proficiency panels for confirmatory laboratories are available on a national scale in 14/26 (54%) countries, of which 8/14 (57%) are organized by governmental agencies.

Issues of Special Interest

The workshop organizers selected a number of circum- stances which were unique, or illustrated specific approaches to regulation, testing or QC. A selection is summarized below.

Testing for Serum Neopterin Levels: Austria Dr. Schoenitzer explained that donor testing for elevated

serum neopterin levels was mandatory in Austria. Although the biochemical and physiological function of neopterin is not well established, levels are elevated in some bacterial, and most viral and parasitic infections, often before clinical symptons or antibodies are detected. Some of the factors favouring the use of this test are as follows: an assumed, but


Vox Sang 1996;70:5340 57

unproven, increase in safety by preventing the transmission of agents for which tests are not currently performed (HAY parvovirus Bl9, EBV); the availability of an EIA test kit; documented elevation in 20% of anti-HIV-negative drugusers, and a moderate donor loss of 2-3%. Factors which may be considered to be negative include the non-specificity and poor reproducibility of the test, difficulty in estab- lishing an appropriate cut-off value, and the fact that the only data supporting a narrowing of the HIV window period came from drugusers rather than blood donors.

Discontinuation of Syphilis Testing: Denmark Dr. Wantzin explained that the requirement for syphilis

testing had been eliminated in 1983 by the Danish National Board of Health. Factors favouring this decision included the following: the known occurrence of known false-negative reactions, especially in the highly infectious early stage; the loss of viability of spirochetes after > 72 h storage at 4”C, and the availability of successful treatment in case of recipient infection. In addition, a cost-effectiveness analysis based on 1971-1981 data revealed that donor testing in- curred expenditure of DKr. 70000000 per case prevented. Arguments for retaining syphilis testing are that transfusion syphilis, although extremely rare, can occur, and that it may be a surrogate marker for individuals at risk for HI\!

HI V Antigen Testing: German.y Dr. Knoedler explained that HIV antigen testing is re-

quired for blood donors in Germany. Factors favouring the requirement are that the test is available, it is simple and has a specificity 99.83%. Additionally, a decision of the Ger- man Supreme Court in 1991 required that all available measures should be taken to provide ‘maximum HIV safety’. However, there has been no confirmed case of isolated HIV antigenaemia among 2 000000 donations as of January 1994, and it is possible that the test might be counter-pro- ductive by attracting individuals at risk to donate in order to be tested. The test also has an unfavourable cost-effectiveness in countries with a low incidence of HI\!

Discontinuation of Multiple t i l V Tests: Switzerland Dr. Burckhardt explained that a requirement for the si-

multaneous use of two separate anti-HIV screening tests had been discontinued in 1991 in Switzerland. The rationale for performing such replicate testing reflected a conflict be- tween regulations in Switzerland and the United States. The US FDA required that stable blood derivatives distributed in the US be prepared from units tested with a FDA-licensed kit (then of first-generation sensitivity), while testing ‘ac- cording to the state of the art’ (i.e. second-generation kits)

was mandatory in Switzerland. From January 1989 to Au- gust 1991, when delivery to the USA stopped, 449 580 donations were tested with two assays and all 22 confirmed positive donors were detected with both kits; 3/22 gave border- line signals with the first-generation assay. Consequently, the use of the first-generation assay was abandoned on the basis of performance data.

Deferral Registers: United States Dr. Bianco pointed out that the US FDA requires the

maintenance of records to identify donors previously found unsuitable on the basis of test results (whether confirmed or not), unacceptable risk histories, or a number of other factors. Subsequent donations from these individuals must be discarded, regardless of the current test results. National files are maintained by the American Red Cross, regional and local files are maintained by other blood centres and hospitals. These files include donors with a repeatedly reactive screening test (one hit for HIV, HCV and HBsAg, two hits for HBcAb, ALT, HTLV) or medical history data. For some markers, re-entry may be performed with FDA-approved algorithms, using licensed confirmatory tests. Inap- propriate release of units from deferred donors constitutes up to 30% of the errors reported to the FDA.

Uniform International Control Procedures: United Kingdom Dr. Robinson explained the system of Common Internal

Controls and central collation of the data generated in Eng- land. The National Blood Transfusion Service obtains and distributes control samples nationally. The controls are han- dled and tested routinely, and data are collected and ana- lysed by manufacturer, procedure and batch. The raw data (including signal levels) are reviewed an a regular basis, thus providing comparative data for judgement of tech- nique, manufacturer, reagent lots and centre competence plus trend analysis.

External QC and Proficiency Programmes Drs. Knoedler, Lindholm, Burckhardt and Polesky ex-

plained the organization of external QC programmes in Germany, Sweden, Switzerland and the USA, respectively in Germany, external QC is required by national guidelines; INSTAND (Institute for Standardization and Documenta- tion) distributes two coded samples, one normal and one pathological, twice a year. The results are collated by IN- STAND and each participant receives the overall results of the programme and, if applicable, a certificate, which is val- id for 1 year. Sites which fail to achieve certification may be ineligible to provide other test results to regional health au-

58 Vox Sang 1996;70:53 -60 van der Poel/Noel/Barbara/Dodd

thorities, may have problems with billing private health in- surance companies, and may be at risk for litigation for mal- practice due to violation of regulations.

In Sweden, external QC is organized by SEQLA (Swed- ish External Quality Assurance in Laboratory Medicine). SEQLA consults expert groups in clinical microbiology and transfusion medicine, designing a blind panel in collaboration with the Swedish Institute for Infectious Disease Con- trol. The programme is based on voluntary assessment of a panel including 7 samples with HBsAg, anti-HIV-I, anti- HCV and anti-HBc. The panel ist sent to all blood-donor- screening facilities, the results are collated and evaluated by SEQLA but, by agreement, SEQLA may not report the results from individual laboratories. However, governmental agencies may request the information directly from the par- ticipating laboratories.

In Switzerland, external QC is performed by the Central Laboratory of the Blood Transfusion Service (ZLB) of the Swiss Red Cross. Two mailings of 40 samples are sent to 52 participants. The panels include samples to be tested for HBsAg, anti-HIV, ALAT (ALT), anti-HCV and syphilis. The programme has educational goals, but the ZLB intends to develop future policies to prevent shipment of plasma from laboratories with unacceptable performance standards and to inform cantonal health authorities. In future, a federal institution (‘inspectorate’) will be responsible for pharma- ceuticals and blood products, in place of 26 cantonal authorities.

In the USA, the American Association of Blood banks (AABB) in collaboration with the College of American Pa- thologists (CAP) mails 3 panels yearly, each including 5 challenge samples for HBsAg, anti-HBc, anti-HCV, anti- HIV-1, anti-HIV-2, anti-HIV-I, ALT, STS and anti-CMY The panel is designed by a committee of transfusion medicine experts, and is intended to evaluate screening and confirmatory testing. The data are collated by the CAP for analysis and reported to participants and regulatory agencies; the program meets a number of federal and state requirements for proficiency assessment.

Donor Re-Entry: The Netherlands Dr. Lelie explained the Dutch guidelines for re-entry of

blood donors after a previous indeterminate anti-HIV West- ern blot result. Factors favouring this position include the frequent occurrence of indeterminate anti-HIV Western blot results among low-risk blood donors the proven absence of infection or infectivity when such patterns are per- sistent over time, the finding that such donors are often negative when tested with subsequent, more sensitive versions or generations of screening tests, and the concept that in-

clusion of HIV-Ag testing in the confirmatory strategy may rule out false-negative Western blot results in the early phase of infection. In addition, the inclusion of PCR in the test algorithm adds security to the interpretation. It was also pointed out that donors should not be deferred for inappro- priate reasons. However, it was recognized that re-entry pro- tocols are complicated and exact compliance is difficult.

Use of a second EIA for Product Release: United Kingdom Dr. Robinson explained that, in England, products from a

donor with a previous false-positive screening test result could be released on the basis of a current negative result in an alternative screening test. Anti-HIV/HCV-screening- test-positive blood donors are reinstated 6 months after a negative or indeterminate result from the reference laboratory and blood may be released for donation thereafter on the basis of a negative result using the alternative screening test. This reflects the finding that non-specific reactivity is often restricted to a single manufacturer’s screening test.

Anti-HBc Screening: Japan Dr. Okochi explained the Japanese system of testing in

which those donors with high titres of anti-HBc, in the absence of anti-HBs, are deferred. Among the issues are the following: anti-HBc testing was not introduced as a surrogate marker for HCV, but as an additional screening test for cryptogenichariant HBV infection; low anti-HBc titres (5 1:64) are ‘further confirmed’ with anti-HBs: if the anti- HBs titre is I 1 : 16, the donor is considered to have resolved an HBV infection and the donation is released.

Testing Pools of Samples with PCR: The Netherlands Dr. Lelie explained a proposal for testing pooled dona-

tion samples with PCR for HBV, HIV and HCV, prior to in- corporation into pools for fractionation. It was suggested that blood donations in the window phase may contain high- er virus loads in the absence of antibody and thus inactiva- tion procedures in such cases might not be totally effective in eliminating infectivity, particularly if titers > lo6’ viral particles/ml occur. Currently, if seroconversion in a donor is reported to the plasma fractionation centre, plasma (product) pools containing the previous donation are destroyed; this could be prevented with earlier detection of infection by PCR. However, some negative aspects of the proposal are that PCR assays are not very well standardized, results from different laboratories may not be consistent, and studies in the USA showed no detection of additional infectious samples using HIV-DNA PCR on pooled donor samples.


Vox Sang 1996;70:5340 59

Conclusions

Perhaps the most outstanding message from the workshop was the great variety of regulatory approaches to blood donor testing among those countries represented. It is clear that there is uniform concern about the safety of the blood supply, but the extent to which agencies manage the achievement of such safety varies widely. Some regulations and practices are clearly founded upon the responsible assessment of data, whereas in others, approaches are based upon a desire to generate improvement, but without rigorous evaluation ahead of time. Although clearly a rarity, there were some examples of relaxation of a regulatory requirement, which would appear to be a desirable trend where appropriate. Another clear message was that QC measures are increasingly being employed, and that such measures are also acquiring regulatory importance.

Acknowledgements

We gratefully thank Prof. W.G. van Aken, Dr. H.W. Reesink, mem- bers of the ISBT Congress organization and Dr. E. F. van Leeuwen for their warm support. This project was financially sponsored by Ortho Diagnostic Systems Europe.

60 Vox Sang 1996;70 53-60

Appendix

Participants in this workshop were:

Dr. D. Sondag-Thull, Belgium Dr. L. Muyle, Belgium Dr. S. Wendel, Brazil Dr. P. Gill, Canada Dr. P. Wantzin, Denmark Dr. E. A. E. Robinson, England Dr. A. Slopecki, England Dr. T. Krusius, Finland Dr. J. Koistinen, Finland Dr. A.M. Courouce, France Dr. P. Maissoneuve, France Dr. S. Voisin, France Dr. J. M. Lemaire, France Dr. P. Kiihnl, Germany Dr. B. Knoedler, Germany Dr. A. Maniatis, Greece Dr. S. Leong, Hong Kong Dr. C.A. Medgyesi, Hungary Dr. T. Walsh, Ireland Dr. A. Zanella, Italy

Dr. G. Sirchia, Italy Dr. H. Kiyokawa, Japan Dr. K. Okochi, Japan Dr. M. Shimizu, Japan Dr. J. C. Faber, Luxembourg Dr. D.G. Woodfield, New Zealand Dr. B. Solheim, Norway Dr. D. Schoenitzer, Austria Dr. J . D. Cash, Scotland Dr. C.T. Fang, Singapore Dr. A. R. Bird, South Africa Dr. J. Montero, Spain Dr. R. Garcia de Villaescusa,

Dr. A. Lindholm, Sweden Dr. J. J. Burckhardt, Switzerland Dr. P.N. Lelie, The Netherlands Dr. C. Bianco, USA Dr. G . E. Tegtmeier, USA Dr. H. F. Polesky, USA

Spain

van der PoelMoellBarbardDodd

Documents

ISBT Working Party on Transmissible Diseases: Report on the Workshop ‘Infectious-Disease Testing and Quality Control’