West Nile Virus Workshop - January 9, 2003

An International Regulatory Consultative Workshop on the issue of West Nile Virus (WNV) was organized and sponsored by Health Canada on January 9, 2003. There is current evidence that WNV can be transmitted via blood transfusion or transplantation but, to date, no test is available to screen blood donations. The meeting involved over 120 delegates from federal, provincial, territorial ministries, members of the public, test kit manufacturers, industry, health care professionals, as well as, internationally recognized scientists working on WNV. Key international speakers reviewed the State of the Art knowledge in this area and Health Canada presented current options for managing WNV risk and solicited feedback from stakeholders on approaches to address risk.

For more information regarding West Nile Virus.

Programme

• West Nile Virus Regulatory Consultative Workshop Programme

Biographies and Presentations

Session I: Managing West Nile Virus Risk

• WNV Safety & Regulatory Overview Canada - Dr. P. Ganz
• Update on Development of Donor Screening Assays for West Nile Virus - Dr. H. Nakhasi
• Transfusion Transmission of West Nile Virus - Dr. M. Chamberland
• Biography of Ms. J. Hill (Chair)

Session II: West Nile Virus Testing

• WNV Surveillance and Testing - Canada - Dr. M. Drebot
• WNV Testing Development - Roche Update - Dr. J. Gallarda
• Procleix WNV Assay: Transcription-mediated Amplification Assay for the Detection of West Nile Virus RNA - Dr. J. Linnen
• Demonstration of Inactivation of WNV and Other Flaviviruses - Pathogen Inactivation of Blood Components - Dr. P. Metzel
• Biography of Dr. R. Peterson (Chair)

Session III: West Nile Virus Operations Perspective

• CBS's Response to WNV as a Threat to the Safety of the Blood Supply - Dr. E. Vamvakas
• Héma-Québec and the West Nile Virus - Dr. G. Delage
• Biography of Dr. B. Casley (Chair)

Session IV: Discussion and Recommendations

• Red Breakout Group: Question#1 - What are the key messages to be communicated to the public about WNV risk? About transfusion and transplantation risks?
• Green Breakout Group: Question#2 - What strategies should be considered to reduce risk of WNV transmission through transfusion or transplantation? Pros and Cons considered for each strategy.
• Blue Breakout Group: Question#3 - What processes can be put in place to facilitate development of testing for WNV?
• Yellow Breakout Group: Question#4 - What measures should be considered to reduce risk if tests for WNV are not available?
• Purple Breakout Group: Question#5 - What areas of WNV research need focused attention?
• Biography of Dr. A. Klein (Chair)

Workshop Summary

• Workshop Summary Report

West Nile Virus Consultative Workshop Programme

Help on accessing alternative formats, such as Portable Document Format (PDF), Microsoft Word and PowerPoint (PPT) files, can be obtained in the alternate format help section.

Contact : CERB/CBE

CROWNE PLAZA HOTEL
OTTAWA, ONTARIO

JANUARY 9, 2003

Organizing Committee

Dr. Peter Ganz
Ms. Cristina Pecora
Mr. Peter Neumann
Dr. Farid Hindieh
Dr. Agnes Klein

OCAPI Facilitators

Ms. Fern Levine, Co-ordinator
Ms. Caroline Vaughn
Ms. Susan Tessier
Ms. Heather McGregor
Ms. Michelle Reimer
Dr. Basanti Ghosh
Ms. Charlotte Tremblay

Workshop Planning

Dr. Peter Ganz
Ms. Cristina Pecora
Ms. Julia Hill

Administration

Ms. Cristina Pecora
Ms. Judy Corbishley
Ms. Pauline Fournier
Ms. Francine Latremouille
Ms. Jeannine Vanker

Programme

Time:	Agenda:	Organization/Speaker
Session I	Managing West Nile Virus Risk - Chaired by: Ms. Julia Hill
8:00 a.m. - 8:10 a.m.	Welcome and Introduction	Ms. Diane Gorman Ms. Julia Hill
8:10 a.m. - 8:30 a.m.	WNV Safety & Regulatory Overview Canada	Dr. Peter Ganz (HC)
8:30 a.m. - 9:00 a.m.	WNV and Safety of the US Blood Supply	Dr. H. Nakhasi (FDA)
9:00 a.m. - 9:30 a.m.	WNV and Transfusion/ Transplantation Risk	Dr. M. Chamberland (CDC)
9:30 a.m.- 9:45 am	Questions and Answers Session
9:45 a.m. - 10:00 a.m.	BREAK

Question #5

What areas of WNV research need focused attention?

Participants

Dr. A. Mortimer
Dr. D. Sutherland
Dr. P. Buck
Dr. E. Farzad
Mr. E. Morrier
Dr. A. Doty
Dr. P. Webber
Dr. S. Roberecki
Dr. K. Grimsrud
Dr. A. Corriveau
Dr. G. Rock
Ms. J. Hamilton
Dr. E. Charbonneau
Mr. I. Mumford
Dr. R. Lemieux
Dr. M. St-Louis
Dr. H. Nakhasi
Dr. W. Graham
Ms. S. Poirier

Rapporteurs:

Dr. H. Artsob & Dr. W. Casley

Facilitator:

Ms. H. McGregor

Time:	Agenda:	Organization/Speaker
Session II	West Nile Virus Testing - Chaired by: Dr. Robert Peterson
10:00 a.m. - 10:20 a.m.	WNV Surveillance and Testing - Canada	Dr. M. Drebot (PPHB)
10:20 a.m. - 10:40 am	WNV Testing Development - Update	Dr. James Gallarda Roche Diagnostics
10:40 a.m. - 11:00 a.m.	West Nile Virus Update	Dr. J. Linnen (Gen-Probe)
11:00 a.m. - 11:20 a.m.	Pathogen Inactivation Technology and West Nile Virus	Baxter Co. (TBA)
11:20 a.m. - 11:45 am	Questions and Answers Session
11:45 am - 12:30 pm	LUNCH BREAK
Session III	West Nile Virus Operations Perspective Chaired by: Dr. Bill Casley
12:30 pm - 12:50	CBS's Response to WNV as a threat to the Blood Supply	Dr. E.Vamvakas (CBS)
12:50 pm - 1:10 pm	Héma-Québec and West Nile Virus	Dr. Gilles Delage (HQ)

Question #4

What measures should be considered to reduce risk if tests for WNV are not available?

Participants

Dr. R. Peterson
Dr. A. Dudani
Mr. E. Ouimette
Ms. K. Farrell
Dr. C. Costello
Ms. N. Fauchir
Ms. H. Gagne
Dr. H. Arruda
Dr. C. D'Cunha
Dr. R. Findlater
Mr. V. Scalia
Mr. A. Roch
Mr. W. Rees
Ms. S. Thibault
Dr. P. Chan
Mr. W. Busch
Dr. M. Chamberland
Mr. B. Mindell
Ms. J. Vilk
Dr. L. Nicolle

Rapporteurs:

Dr. P. Sockett & Dr. W. Stevens

Facilitator:

Mr. R. Leitch

Time:	Agenda:	Organization/Speaker
Session IV	Discussion and Recommendations - Chaired by: Dr. A. Klein
1:30 pm - 1:40	Introduction to Facilitated Sessions - OCAPI and TPD	Ms. F. Levine
1:40 pm - 3:00	Breakout Sessions	OCAPI Facilitators
3:00 pm - 3:15 pm	BREAK
3:15 pm - 4:00	Breakout Sessions - continued
4:00 pm - 4:50	Summaries and Discussion of Breakout Sessions
4:50 pm 5:00	Closing Remarks & Adjournment	Dr. P. Ganz (BGTD)

Question #3

What processes can be put in place to facilitate development of testing for WNV?

Participants

Dr. K. Nyarko
Dr. M. Drebot
Mr. D. Boyer
Dr. C. Legare
Dr. J. Linnen
Dr. J. Gallarda
Dr. M. Baikie
Dr. C. Balram
Dr. M.Kjerulf
Dr. H. Hume
Dr. F. Decary
Ms. S. Remy-Prince
Mr. B. Kane
Dr. K. Kovacs Burnes
Ms. L. French
Ms. J. Sirna
Mr. E. Chabot

Rapporteurs:

Ms. Maria Carballo & Dr. Lindsay Elmgren

Facilitators:

Ms. Michelle Reimer (Dr. Basanti Ghosh)

Question #2

What strategies should be considered to reduce risk of WNV transmission through transfusion or transplantation? Pros and Cons considered for each strategy?

Participants

Dr. Roland Rotter
Dr. S. Sharma
Dr. H. Njoo
Mr. J. Lambert
Dr. E. Griffiths
Ms. J. Koch
Dr. R. Vadehra
Ms. T. Chong-King
Dr. F. Stratton
Dr. L. Sweet
Dr. I. Gemmill
Dr. E. Vamvakas
Dr. M. Germain
Dr. P. Dubord
Dr. J. Teitel
Dr. D. Wong-Rieger
Ms. S. Comerford
Dr. L. Petersen
Ms. D. Tremblay
Ms. M. Hand
Dr. T. Bowen

Rapporteurs:

Mr. P. Neumann and Dr. F. Hindieh

Facilitator:

Ms. S. Tessier

Question #1

What are the key messages to be communicated to the public about WNV risk? About transfusion and transplantation risks?

Participants

Dr. A. Klein
Ms. B. Benning
Ms. R. Dansereau
Dr. S. El Saadany
Dr. L. Stringfellow
Mr. B. Labossiere Bees
Mr. P. Chapman
Dr. B. Larke
Dr. M. Fyfe
Dr. L. Heubsch
Dr. G. Sher
Dr. G. Delage
Dr. B. Singh
Dr. J. Freedman
Mr. G. Dafoe
Ms. E. Chatigny
Mr. M. Fruitman
Mr. R. Legault
Ms. L. Stevens
Mr. D. Page

Rapporteurs:

Dr. A. Giulivi & Mr. K. Moore

Facilitator:

Ms. C. Vaughn

Questions for Breakout Sessions

1. What are the key messages to be communicated to the public about WNV risk? About transfusion and transplantation risks? Rapporteurs : Dr Antonio Giulivi et Mr. Ken Moore
2. What strategies should be considered to reduce risk of WNV transmission through transfusion or transplantation? Pros and Cons considered for each strategy. Rapporteurs : M. Peter Neumann et Dr Farid Hindieh
3. What processes can be put in place to facilitate development of testing for WNV. Rapporteurs : Mme Maria Carballo et Dr Lindsay Elmgren
4. What measures should be considered to reduce risk if tests for WNV are not available? Rapporteurs: Dr Paul Sockett et Dr Will Stevens
5. What areas of WNV research need focused attention? Rapporteurs : Dr Harvey Artsob et Dr Bill Casley

Peter Gantz - WNV Safety & Regulatory Overview Canada

Contact : CERB/CBE

Peter R. Ganz - Biographical Sketch

Dr. Ganz received both his bachelors and doctoral degrees in Toronto. As a Leukemia Society of America Fellow, he continued his post doctoral training in the Department of Microbiology and Parasitology, Faculty of Medicine at the University of Toronto working in the area of tumour virology. His interest in the biochemistry and molecular genetics of blood proteins moved him to Ottawa to take up an appointment as Research Director at the Ottawa Blood Centre, Canadian Red Cross Society. During his tenure at the CRCS, Dr. Ganz researched the molecular mechanisms of action of clotting and fibrinolytic factors and their interaction with platelets and human endothelial cells. This research work evolved to include highly cited studies on the expression of pharmaceutically important proteins in transgenic plant systems.

Dr. Ganz moved to the Bureau of Drug Research at Health Canada in 1996 and then to the Bureau of Biologics and Radiopharmaceuticals and later the Biologics and Radiopharmaceuticals Evaluation Centre as Chief/Manager of the Blood and Tissues Division. During his 15 years of active experience in the blood area, he has authored over 80 research articles and reviews and received international recognition for research including an International Thrombosis and Hemostasis Investigator Award. Since 1982 he has held a cross appointment as an Adjunct Professor in the Department of Biochemistry, Microbiology and Immunology at the University of Ottawa as well as the School of Graduate Studies and Research.

Dr. Ganz contributes his expertise to a number of National and International Committees including the Canadian Standards Association Technical Committee developing National Blood Standards and Committees of the World Health Organization, Council of Europe and United States Pharmacopoeia..

WNV Safety & Regulatory Overview Canada

Dr. Peter Ganz
Blood, Tissues and Organs Division
Biologics and Radiopharmaceuticals
Evaluation Centre, BGTD

West Nile Virus- Background

• WNV is a mosquito-borne flavivirus with a natural reservoir in different species of birds
• Most people infected with WNV develop no symptoms or only minor disease with fever, headaches, skin rash and body aches and sometimes swollen lymph nodes
• less than 1% develop serious health effects associated with neurological disease (encephalitis or meningitis)
• There is no specific treatment or vaccination and most of infected individuals recover
• WNV infection exhibits a brief period of viremia prior to the onset of symptoms

West Nile Virus- Transmission Through Transfusion & Transplantation: What do we know?

• In Sept 2002 U.S. Centers for Disease Control and Prevention (CDC) confirmed that 4 individuals who received organs during transplantation from a single organ donor were infected with WNV.
• WNV infection was confirmed by NA testing of serum from the organ donor: 3 organ recipients developed encephalitis with 1 death.
• Organ donor infected with WNV by mosquito exposure or through transfusion (63 units of blood transfused)
• Other subsequent confirmed reports of transmission of WNV through blood transfusion

West Nile Virus- Transmission through Blood

• Clear evidence of transmission through blood
• Higher risk of infection through mosquito bites than by Blood Transfusion
• WNV can survive in RBC units for at least 26 days, some data that other blood components may also harbour the virus. 44 days in FFP; platelets- 5 days. More studies are needed.
• In U.S., 14 cases of transmission of WNV through transfusion
• In Canada, 2 possible cases of transmission of WNV through transfusion

West Nile Virus- Paths to Human Infection

• Blood Transfusion
• Organ transplantation
• Mosquito bites
• Intrauterine infection
• Occupational exposure-percutaneous transmission
• possibly breast milk

West Nile Virus: Managing Risks

General Measures for WNV infection

• Co-operative action by all stakeholders, multi-jurisdictional co-operation
• Active Surveillance System to detect WNV activity
• Education & Prevention: Reduce Exposure
• Communication re: exposure risks
• Vector abatement and control measures

West Nile Virus: Managing Risks-Blood

• Blood donor screening tests or pathogen inactivation for WNV would provide effective risk management strategies
• Contingency planning for options in the event that tests or pathogen inactivation for WNV may not be available
• For test development
  • Industry to move early WNV tests in an expedited fashion through development pipeline to a validated test to screen blood donors
  • Blood operators to have in place processes to adapt new technology in a timely manner
  • Health Canada to have in place flexible regulatory regime to review data for approval of tests

West Nile Virus- Risk Management Options-Blood

• Pre-donation screening-rigorous assessment
• Post Donation action on probable cases
• Post Donation action on confirmed cases
• Retrieve blood components collected during mosquito season-replace with "out of season" components; stockpiling of latter
• Obtain blood from low risk areas for "high risk" patients
• Consideration of introduction of pathogen inactivation technologies
• Testing of donated blood for WNV

West Nile Virus- Options to Reduce Transfusion Risk-Status

Option:

• Retrieve blood components collected during mosquito season-replace with "out of season" components
  
  Comment:
  Both CBS and HQ have recalled frozen components and begun to replenish inventory. Inventories of frozen components could be built up for use during mosquito season.

Option:

• Obtain blood from low risk areas for susceptible patients
  
  Comment:
  Surveillance data is essential to developing a geographic risk assessment on which to base decision making. Animal, mosquito and human data are highly informative. Needs to be considered further by all stakeholders.

Option:

• Consideration of introduction of pathogen inactivation technologies
  
  Comment:
  Technology is new. Only one approved methodology in Canada which would require major changes to blood operations to implement across Canada. Needs to be further considered with stakeholders.

Option:

• Testing of donated blood for WNV
  
  Comment:
  A highly favoured option. However, there is currently no WNV donor screening test. Health Canada would expedite review and give highest priority to operational implementation of an investigational test. Health Canada is working with Industry, blood operators to test feasibility of implementing tests in 2003

Option:

• Selective Testing of donated blood for WNV
  
  Comment:
  Instead of testing all blood, only components destined for high risk patients would be tested. As part of contingency planning, this option has been discussed with both CBS and HQ.

West Nile Virus- Test Development: Challenges

• WNV serological based screening tests for donor screening are not ideal
• Even when using NA based tests, titres of virus may be low and this complicates testing of more dilute minipools
• Several unknowns e.g. period of viremia, infectious dose, prevalence in donors, transfusion transmission incidence rate etc.
• Need to develop reference standards, reagents and test panels
• While recognizing that a Nucleic Acid based test for WNV donor screening is a preferred option:
  • Moving a research or clinical diagnostic test to a full fledged donor screening test, including regulatory approval and implementation in a manufacturing environment, is generally a very lengthy process (several years).
  • Reducing this timeframe will represent a considerable challenge for all stakeholders

West Nile Virus- Testing in Canada: Status

• Health Canada has been in contact with Industry to discuss the status of their WNV testing programs and to discuss regulatory options for bringing these tests to market in Canada.
• Health Canada has met with CBS and HQ to discuss interest and feasibility of moving existing research and diagnostics WNV tests to within blood operators manufacturing environment.
  • This is one of several options to be considered as part of contingency planning in case no test is available

West Nile Virus- Health Canada Actions to Date

• Managing WNV Risk is a high priority for Health Canada
• Formed internal working group on WNV.
• WNV Issues raised, options discussed with EAC-BR
• Reviewed options and issued requirements to operators indicating:
  • no additional tests or donor screening questions are required at this time
  • for confirmed cases, products are to be withdrawn and donor deferred
  • for probable cases, products are to be quarantined and donors deferred
  • no requirement for retrieval of plasma once pooled for fractionation
• Active surveillance system for WNV has been established across Canada
• Working with Provincial and Territorial Health Authorities, procedures have been established for recording and transmitting case data from physicians/hospitals to provincial labs to CBS and HQ
• Health Canada is working with all jurisdictions in testing of WNV in Canada

Summary

• Health Canada is moving forward with various options to address WNV risk
• Development of tests for WNV are being closely followed and Health Canada will analyze data and prepare recommendations for test implementation once a test is available
• Health Canada will continue to evaluate the potential impact of WNV risks in the area of transfusion and transplantation and will take steps to ensure that adequate measures are in place to protect the public

Update on Development of Donor Screening Assays for West Nile Virus

Contact : CERB/CBE

Hira Nakhasi, Ph.D.
Office of Blood Research and Review
CBER, FDA

Background Information

• WNV is a mosquito-borne falvivirus
• WNV has a positive strand RNA genome of about 11 kb that encodes several proteins
• Primarily infects birds, occasionally also infects humans and horses
• About 80% of infected persons remain asymptomatic, rest 20% develop mild febrile illness (flu-like illness)
• Meningitis or encephalitis develops in ~1 in 150 infected persons
• Viremic period can occur up to 2 weeks prior to symptoms and last up to a month from the initiation of the infection
• Blood transmission of WNV has been confirmed in the recent US outbreak. However the magnitude of the risk of WNV from transfusion is unknown.
• Virus titer in blood is low compared to other transmissible viruses (~10³ copies/ml) and the viremia is transient.
  • Viremia in encephalitis patients can be as high as 2.5x10⁶ copies/ml
• Viremia resolves rapidly after seroconversion to IgM
• IgM can persist for a long time in some cases up to a year
• WNV infection does not become chronic

West Nile Virus and Blood Safety: FDA's Actions to Date

• Alert notices posted on FDA's website: and October 3, 2002
  • August 17, 2002: Vigilance in excluding symptomatic donors urged prior to any actual report of transmission
  • October 3, 2002: FDA states its interest in facilitating development of donor screening & supplemental tests
• Cooperation with CDC, State Public Health Departments, Blood Organizations and HRSA
  • Epidemiological investigation of all possible cases of transfusion transmitted WNV
  • Advice provided on deferral of donors and withdrawal of in-date products collected from suspect donors
• Timely and ongoing communication with blood community, health professionals, media, congress & consumers
  • Stimulate case reporting
  • Balanced message on risk of WNV
    • Risk of WNV higher from mosquito bites
    • Risks and benefits of transfusion, transplantation
    • Uncertainty of current knowledge base
    • Congressional hearings on September 10 & 24, and October 3, 2002

West Nile Virus and Blood Safety: Current FDA Initiatives

• FDA Guidance on donor and product management
• Facilitate development of screening and supplemental tests
• Cooperation with CDC, NHLBI and Blood Organizations on rapid surveys of WNV incidence in donors
  • Unlinked study by CDC
  • Linked study by industry coordinated through REDS
• Identify needs for additional research
  • WNV inactivation by storage
  • WNV removal and inactivation during plasma fractionation
  • Serosurveys in frequent blood product recipients

Goals of the WNV workshop held in NOV '02

• Current status of WNV pathogenicity and epidemiology in the US
• Review of methodologies that are suitable for blood/tissue donor screening
• Industry perspective on the development of WNV screening assays that are suitable for large scale screening
• Strategies aimed at inactivation of WNV
• Review of proposed studies on prevalence in donors
• FDA's expectations for licensure of WNV test
• Issues relevant to implementation of WNV test

Current status of WNV pathogenicity and epidemiology in the US

• In year 2002 total number of WNV cases reported were 3829 out which 225 deaths.
• Whole of USA is endemic for WNV
• Viremia generally begins from 1-5 days before the onset of symptoms and lasts an average of 6 days
• Estimated risk of 1-2 infections per 10,000 donations nation wide but can be high in highly endemic regions (16/10,000 with a mean of 6-8/10,000)
• So far 47 possible Transfusion-Transmitted cases reported
  • 13 are confirmed,14 are not transfusion related, rest are under investigation
• WNV transmission is at its peak between late Aug- late Sept

Review of methodologies suitable for blood/tissue donor screening

• Serological (detection of WNV IgM antibodies):
  • Use of recombinant antigen, microsphere immunobead assay
  • Cross-reactivity with SLE, DEN, JE
  • High through put, low specimen volume (10 µl for serum and 30 µl for CSF), Multiplexed, short turn around, and can be adapted to other platforms
• Nucleic acid based tests (NAT):
  • Std PCR, Taqman RT-PCR, SYBER green RT-PCR, NASBA
  • High through put; 80- 300 samples can be extracted and analyzed
  • Detection limits 15 PFU/ml to 15,000 PFU/ml
  • Caveats: average human viremia is 18 PFU/ml
  • Minipool NAT detection rate is 50%, need to adopt smaller pools or ID-NAT.
• CSF have higher level of viremia (sensitivity 0.1- 0.5 Pfu/ml)
• Rare cases WNV RNA can be detected in the presence of antibody
• WNV IgM can remain positive for greater than one year, long after infectivity has ended
• NAT could be the preferred choice for testing
• IgM assays could be used as confirmation of NAT results, diagnosis and epidemiological surveillance
• WNV remains for a long time in kidney -implication for organ donation
• If Blood is screened, it will have positive impact on tissue/organ donations
• There is a need for test suitable for cadveric samples.
• Development of animal models to study WNV transmission by transfusion
• Development of WNV specific control panels
  • Training panels; Heat treated virus spiked into defibrillated plasma

Industry perspective on the development of WNV screening assays

• Industry representatives presented plans with little data
  • NGI:-WNV NAT sensitivity is ~100 copies/ml (10- 200 copies/ml)
  • Asymptomatic donors prevalence rate is 1:8,000 in samples collected during Aug-Sept. Some donations with high titers can be detected in pools of 64 or 512
  • GenProbe:-Validation data of TMA assay using synthetic RNA ( 7.6 copies/ml) and viral lysate (2x10-⁶ copies/ml)
• Development of test will be under IND/BLA mechanism
• Planning to have the validated test ready by Beginning of 2003 and testing under IND by middle of 2003.

Strategies aimed at inactivation of WNV

• Several manufacturers using methods such as solvent detergent, Psorlin, Riboflavin, Inactine treatment for viral inactivation of plasma, platelets, RBC also showed inactivation of WNV by such methods WNV ( > 4 log reduction ).
• WNV survives in RBC at 4⁰C and in blood bank conditions as well as in leukocytes.
• No need to demonstrate WNV specific inactivation
• Need to show WNV specific inactivation similar to HIV and HCV, adds a layer of safety
• Caveats:
  • Adverse events due to treatment of blood products
  • Immunological reactivity including anaphylaxis
  • Increased sensitivity of blood cells to other drugs
  • Specificity of the inactivation methods (pathogen vs host)
• Studies needed to assess the risk

Review of proposed studies on prevalence in donors

• Linked study (ARC samples ~85,000)
• Research Study ( REDS/TRIPS small number of samples)
• Linked study ( Roche samples, large number)
• Objective:
  • Develop analytical sensitivity panels
  • Compare WNV RNA and IgM assays
  • Prevalence of viremia (viral load, IgM antibody, virus culture status)
  • Compare MP vs ID- NAT
  • Confirm donor viremia by IgM and RNA testing of donor follow up sample
  • Assess disease outcome in Viremic donations, routine "call back" information
  • Establish back ground community-acquired WNV exposure rates
  • WNV incidence and transfusion-transmission rates
  • Exposure rates in recipients by testing autologous donations for IgM reactivity
• Phase I, assess performance of candidate WNV RNA assays validation ( < 50 GEq/ml at 50% detection limit) bench mark against CDC NAT test (completion first quarter of 2003)
• Phase II, test up to 200, 000 samples which includes > 50, 000 high risk samples ( completion by summer of 2003)

Review of proposed studies on prevalence in donors (CBER/FDA efforts)

• Development of Reference Panels for lot release testing
  • Panels to be tested by several laboratories in a collaborative study
• Development of in-house TaqMan PCR and IgM test for WNV
  • Using in-house primers and comparing long side with CDC tests
• Objective:
  • Study viral dynamics and infectious dose
  • Distribution in the blood components
  • Viral tropism
  • Correlation between viral strain and infectious outcomes

Regulatory Pathways for Assay Development

• Donor screening and supplemental tests will be reviewed as biologic products under the PHS Act
  • IND Applications are needed
  • Biological License Applications filed pre-market
    
    
• The instrument and software portion of the application requires a separate 510(k) submission. (See: CDRHGuidance for the Content of Pre-market Submissions for Software Contained in Medical Devices.)
  • A licensed test used for screening blood donors has been determined to be a "major level of concern."
    
    
• FDA guidance on " Current thinking on management of donors and products"

General Validation of Screening Tests

• Analytical sensitivity
• Analytical specificity
• Clinical sensitivity
• Clinical specificity
• Chemistry, manufacturing and controls
• Reproducibility, proficiency
• Reagent and kit stability
• Instruments and software

Validation of Assays in Clinical Trials

• Even if NAT tests alone are selected for donor screening, during clinical trials, specific antibody assays will be needed, for follow-up testing of investigational NAT + donors to validate the NAT + test results.
• Different types of NAT assay also will be useful to validate the results of investigational NAT
  • Use of different primers and probes
  • Cross-over testing with different assay technologies
• Commercially available antibody tests for clinical diagnosis also will be needed.

Screening of Tissue and Organ Donors

• Screening of tissue donors will come under FDA regulation after publication of a final rule on donor eligibility.
  • As proposed, FDA's rule would require use of approved donor screening tests.
  • A need exists to assess effectiveness of WNV screening tests for use with cadveric blood samples.
• Solid organs and bone marrow are regulated by HRSA, however, FDA approval is needed for commercially available screening and diagnostic tests.

West Nile Virus and Blood Safety: FDA's Current Thinking on Management of Donors and Products

• Donors with a medical diagnosis of WNV infection should be deferred until 14 days after the condition is resolved and at least 28 days from onset of symptoms or diagnosis, whichever is the later date. An IgM positive antibody test result alone should not be grounds for deferral.
• Donors who report an otherwise unexplained postdonation febrile illness suggestive of WNV infection in the setting of active WNV transmission in the community should be deferred for 28 days from the onset of illness or 14 days after the condition is considered to be resolved, whichever is the later date.
• In-date components should be quarantined and retrieved if a donor later reports a medical diagnosis of WNV.
  • Product quarantine and retrieval should cover a time period dating back to 14 days prior to the onset of illness and 28 days subsequent to the onset of illness.
  • In the absence of symptoms, an IgM positive antibody test result should not be grounds for product quarantine and retrieval.
• Medical directors should exercise judgment when an otherwise unexplained post-donation febrile illness occurs in the setting of active WNV transmission in the community.
• Donors are considered to be potentially associated with transmission of WNV if the infected recipient received the donor's blood components within the 28 days before the onset of symptoms in the recipient.
• For each associated donor, product quarantine and retrieval should be applied to in-date components that were collected in the period from 28 days prior to the suspect donation to 28 days after the suspect donation.
• When a blood establishment receives information that a donor has a medical diagnosis of WNV, blood establishments should consider notifying transfusion services to permit "lookback" recipient tracing and notification.
• If a post-donation illness is not diagnosed as WNV infection, actions to identify prior recipients are not appropriate.
• When an epidemiological investigation suggests that a specific donor is the likely source of transmission of WNV to a transfusion recipient, "lookback" notification of other recipients is appropriate.

FDA's current thinking for licensure of WNV test

• FDA's current thinking is to recommend routine use of licensed donor screening tests to detect acute donor infections
• Possible use of donor screening tests under IND
• Build on existing test platforms
• Validation in donor screening environment
• Adequate sensitivity to detect low level viremia
• Possible need for individual unit NAT
• Use of technologies ( virus concentration procedures) which will amplify the viral load in samples
• Development of reference panels to standardize different tests

Issues relevant to implementation of WNV test

• Logistic issues for implementation of NAT tests
  • SOP modification, Process Qualification, Space, Biomedical information systems
• Impact on the schedule release of other tests and testing strategies
• Testing
  • Seasonal vs Year round
  • Geographical vs National
  • Need for testing related viruses
  • ID NAT vs minipool NAT
  • Past experiences from SLE epidemic
  • Apply estimated risks to determine the need for donor screening

General Conclusions

• Issues need to be addressed:
  • Sensitivity and specificity of tests and the suitability for large scale screening
  • Infectious viral load, duration of viremia
  • Blood components that transmit infectivity
  • Survival of the infectious agent in blood banking storage conditions
  • Development of confirmatory tests
  • Cross reactivity of WNV with other falviviruses
  • Multiplexing of tests
  • Estimated risk
  • Cost of implementation of a new test and its impact on existing or development of other tests
• Close cooperation between FDA, PHS, Device manufacturers, blood organization in developing tests (NAT/serological) for screening WNV in blood donors
• Testing could start under IND by the next WNV epidemic
• Meanwhile the safety of the blood supply can be ensured
  • In place procedures in blood banking practices
  • FDA guidance on " Current thinking on management of donors and products"

Biography - Dr. Mary E. Chamberland

Contact : CERB/CBE

Centers For Disease Control And Prevention

Mary E. Chamberland, M.D., M.P.H. is the Assistant Director for Blood Safety and the Acting Deputy Director of the Division of Viral and Rickettsial Diseases at the Centers for Disease Control and Prevention (CDC). She received her medical degree from New York Medical College, New York, New York and a Masters in Public Health from Harvard University, Boston, Massachusetts. Dr. Chamberland is responsible for the coordination and direction of CDC's programs and public health policy involving blood safety. During the 2002 West Nile Virus epidemic, she co-led the Transfusion Investigation Team.

Transfusion Transmission of West Nile Virus

West Nile Virus Regulatory Consultative Workshop
Ottawa, Canada
January 9, 2003

Mary E. Chamberland, M.D., M.P.H.
Anthony A. Marfin, M.D., M.P.H.
Lyle R. Petersen, M.D., M.P.H.
Lisa Pealer, Ph.D.

Transfusion-associated West Nile Virus Infection

Background

• Concern about potential transmission
  • Transient viremia
  • Most infections asymptomatic
• "Small but not zero" risk
  • No chronic carriers
  • No cases reported in prior years or from endemic countries
• Estimated risk: 1.8 1.8-2.7/10,000 donations 1999 Queens (NYC) epidemic

West Nile Virus Infection in an Organ Donor and Four Transplant Recipients August 2002

Reports of Possible Transfusion-associated West Nile Virus Infections, by Month of Report in 2002

Investigation of Transfusion-associated West Nile Virus Infection

• Determine number and type of components transfused to recipient in 4 weeks before illness onset
  • Retrieve "initial donation samples" (e.g., retention segments, untransfused components, NAT tubes)
  • Test for WNV RNA (TaqMan rtPCR) and IgM antibody (ELISA)
• Obtain follow-up questionnaire and serum sample and test for WNV IgM antibody
  • Donors of components received by index recipient
  • Co Co-component recipients of donors with evidence of WNV infection at donation

Status of West Nile Virus Transfusion-associated Investigations

• 57 possible cases reported Aug 28, 2002 57 possible cases reported Aug 28, 2002 - Jan 3, 2003 Jan 3, 2003
• 19 not transfusion-associated
  • 8 did not have WNV infection
  • 3 received transfusions after symptom onset
  • 2 had symptom onset >28 days after transfusion
  • 6 had WNV infection but all donors were WNV IgM IgM-negative
• 24 under investigation
• 14 confirmed cases of transfusion-associated transmission

Confirmed Case of Transfusion-associated West Nile Virus Infection

IMPLICATED DONOR: PCR-positive/equivocal initial donation sample(s) AND virus isolation OR seroconversion on follow-up

AND

INDEX RECIPIENT: Onset of probable/confirmed WNV
illness* within 4 weeks of transfusion from implicated donor
or
CO-COMPONENT RECIPIENT: WNV IgM antibody
positive with/without viral symptoms

^*CDC. Epidemic/Epizootic West Nile Virus in the United States: Revised Guidelines for Surveillance, Prevention, and Control, April 2001

West Nile Virus Infections in Recipients of Blood Transfusions August 28, 2002 - January 3, 2003

14 Confirmed Cases

Sex:
6 (43%) male
8 (57%) female

Age:
7 - 75 years (range)
40 years (median)

Confirmed Cases of Transfusion-Associated West Nile Virus Infection August 28, 2002 - January 3, 2003

Confirmed Cases of Transfusion-associated WNV Infection

Cases	Underlying condition	Mosquito Exposure	Outcome
Patient 1	Post partum	Yes	Alive
Patient 2	Liver transplant	Possible	Alive
Patient 3	Post partum	Yes	Alive
Patient 4	AML	No	Alive
Patient 5	Cancer	Unlikely	Fatal
Patient 6	Cancer	Possible	Alive
Patient 7	AML/BMT	Possible	Fatal
Patient 8	Surgery	Unlikely	Alive
Patient 9	AML/BMT	Possible	Alive
Patient 10	Cancer	Possible	Alive
Patient 11	Sepsis	Possible	Alive
Patient 12	CABG	Possible	Fatal
Patient 13	CABG	Possible	Alive
Patient 14	AML/BMT	Unlikely	Fatal

Transfusion-associated WNV Infection
Patient 1 (Post-partum)

Transfusion-associated WNV Infection
Patients 2 (Liver Transplant) and 3 (Post-partum)

Transfusion-associated WNV Infection Patient 4 (AML)

• Patient isolated for 65 days before WNV symptom onset on 9/12
• CSF positive for WNV IgM antibody on 9/25
• Received 93 blood components 8/15 - 9/12
• Of 93 donations, 70 initial donation samples tested
  • 1 plasma co-component, PCR + , IgM - (PLT transfused on 9/1)
  • 1 segment PCR + , IgM - (PLT transfused on 9/8)
  • Both donors IgM + on follow up
  • Donor of 9/8 transfusion reported fever, headache, eye and joint pain 2-4 days after donation; 9/1 donor reported no symptoms

Transfusion-associated WNV Infection
Patient 5 (Cancer)

Transfusion-associated WNV Infection
Patients 5 (Cancer) and 6 (Cancer)

Fourteen Confirmed Cases of Transfusion-Associated West Nile Virus Infection Summary

• Illness onset: August 1 - October 23, 2002
  • 3 recipients - unable to distinguish viral illness
• Days from transfusion to illness onset (N=11)
  • Range: 4 - 23
  • Median: 11
• Duration of PCR+ after illness onset: at least 17 days for 1 patient
• Implicated components
  • 7 units of red blood cells
  • 5 units of platelets
  • 2 units of FFP

Summary of Ten Implicated Donors

• Date of Donation: July 22 - September 20, 2002
• Donor illness onset
  • Pre-donation (N=2)
    • 1 donor: onset of URI symptoms unclear
    • 1 donor: 5 days
  • Post-donation (N=6)
    • 4 donors: 0 - 5 days
    • 1 donor: 11 days
    • 1 donor: within 3 weeks
  • Asymptomatic (N=2)
• Maximum interval from donation to transfusion
  • PLT 5 days; RBC 33 days; FFP 44 days

West Nile Virus Activity in County of Residence for Implicated Donors at Time of Donation

County	Onset 1st case	No. human cases before donation	Date of donation	Lead-time (days)
A	6/27	2	7/22	25
B	7/30	11	8/15	16
B	7/30	105	9/6	38
B	7/30	82	8/30	31
C	8/21	1	8/23	2
D	7/10	118	8/21	42
E	7/20	41	9/9	51
F	8/12	1	8/19	7
G	8/17	4	9/20	34
H	8/08	25	8/31	23

Correlation of PCR Testing of Initial Donation Samples with Follow-up Serology Testing*

Initial Donation Sample	Donor Follow-up IgM Antibody
Retention Segment	No. Positive	No. Negative
No. PCR-positive 8	6	2
No. PCR-negative 3	2	1
Component/NAT Tube
No. PCR-positive 6	4	2A
No. PCR-negative 1	0	1

^* Includes implicated and non-implicated donors

^A. Initial donation samples PCR-positive; re-tested at CDC and 2nd laboratory and determined to be PCR-negative

Correlation of PCR Test Results of Initial Donation Samples by Specimen Type for Implicated Donors

Evidence for West Nile Virus Transmission by Blood Transfusion

• 10 of 10 implicated donors had PCR positive initial donation sample
• WNV isolated from unit of FFP
• 10 of 10 donors seroconverted after donation
• 8 of 10 donors had viral symptoms before or after donation
• Three of fourteen recipients were unlikely to have mosquito exposure
• Four instances of multiple recipients associated with a single implicated donor
• Compatible timing between transfusion, viremia, and symptom onset in recipients

Transfusion-associated West Nile virus Infection Unanswered Questions

• Better definition of clinical course of WNV infection and viremia
• Define scope and magnitude of transfusion transmission
  • Prevalence of viremia in donors
  • Rate of transmission from viremic donors and associated risk factors
  • Seroprevalence in frequently transfused persons
• Transmission of other flaviviruses (SLE, dengue)?

Estimated Risk of Transfusion WNV Transmission, June 10-October 31, 2002

Location	Counties	Average Risk Per 10,000	Max Risk Per 10,000
St. Louis	St. Louis, St. Louis City (MO), Madison, IL	0.85	1.6
Memphis	Shelby	4.1	7.7
Chicago	Cook, Du Page	4.2	10.0
Detroit	Macomb, Oakland, Wayne	5.9	11.8
Cleveland	Cuyahoga	8.3	14.5
ALL US	Lower 48 states	0.33	0.96

Based on data reported through October 31, 2002; estimates are preliminary

Acknowledgement

Presentation of these data was possible only through the efforts and dedication of hundreds of investigators in health departments, blood collection agencies, hospitals, organ and tissue transplant organizations, and federal agencies as well as through the cooperation of donors and patients.

Biography of Ms. J. Hill (Chair)

Contact : CERB/CBE

The Biologics and Generic Therapies Directorate was created through Health Canada's realignment in the spring of 2000. Julia has been with the directorate since its creation, first as Associate Director General and now as Acting Director General.

Julia joined Health Canada in October 1998; within the department, she has also held the positions of Director of the Bureau of Policy and Coordination and prior to that, Associate Director of the Bureau of Compliance and Enforcement.

Julia Hill holds a graduate degree in Social Policy and International Economics, from the University of Manchester, UK. She has been with the government for approximately 15 years.

Prior to joining Health Canada, Julia worked as a Senior Policy Analyst at the Privy Council Office. Before that, over a period of approximately 12 years, she held a variety of positions with the Canadian International Development Agency (CIDA) in areas such as primary health care, women's issues, and private sector development in Asia, Africa and the Americas.

Before joining government, Julia worked in communications and international affairs with the Association of Universities and Colleges of Canada.

Biography - Dr. Michael A. Drebot

Contact : CERB/CBE

I am the Head of the Viral Zoonoses Section within the Zoonotic Diseases and Special Pathogens program , Health Canada, Winnipeg.

My research interests include diagnostic development and surveillance for a variety of zoonotic pathogens such as the West Nile virus and Canadian hantaviruses. As well, I am also involved in studies dealing with the phylogenetic characterization and evolution of arboviruses and tick/rodent-borne pathogens.

West Nile Virus Surveillance and Testing-Canada

Dr. Michael Drebot, ZDSP-NML-Health Canada

WNV Surveillance in Canada: 2000-2002

• Sentinel Chickens
• Dead birds
  • Facilitate early detection of WN virus in Canada
  • Activities focus on testing dead birds (primarily crows, blue & gray jays, magpies and ravens)

• Monitoring activities also included surveillance in:
  • Humans
  • Mosquitoes
  • Horses

Detection of WNV in Bird/Mosquito Samples by PCR

Confirmatory Testing

West Nile Virus Avian Surveillance--- 2001

West Nile Virus Avian Surveillance---2002

Additional WNV Infected Birds and Mammals ---2002

Case Definitions

Suspect Case Definition--- febrile illness + meningitis/encephalitis

Probable Case Definition --- as above + flavivirus seroconversion (HI, ELISAs)

Confirmed Case --- as above + WNV PRNT or WNV PCR or Isolation

Specimens --- serum, CSF, blood, brain tissue

WNV Surveillance "Timelines" --Ontario--

Conclusions

• Dead bird (corvid) surveillance provides a sensitive tool for detecting WNV activity in Canada.
• WNV was first documented in Canada (southern Ontario) in 2001 and the occurrence of the virus in 5 provinces in 2002 has now been shown.
• Infected mosquitoes, non-corvid birds and mammals have been identified
• The first Canadian human cases of WNV disease were confirmed this year (Ontario, Quebec),
• surveillance timelines

WNV Testing Algorithms

Molecular Diagnostics

• Sample Preparation (Nucleic Acid)
• Genomic Amplification
• Post-Amplification Characterization
• Samples Numbers / Throughput--- (SP or GA)
• Sensitivity/Specificity
• Internal Controls / Proficiency Panels

TaqMan Real Time RT-PCR

WNV: PFU vs Genomic Copy Number

Infectivity Ratio: 1 pfu = 500 particles
NAT --- TaqMan (0.1 PFU sens)

Sensitivity of WNV NASBA & Sensitivity of WNV NASBA & TaqMan Assays TaqMan Assays

WNV NY99 virus seed

Quantity	Standard	NASBA			TaqMan
WNV; #pfu	RT-PCR	ECL	Interp.	Ct	Rn	Interp.
100,000	pos	765204	pos	16.62	3.65	pos
10,000	pos	733528	pos	20.3	3.56	pos
1000	pos	480448	pos	24.08	3.43	pos
100	pos	402655	pos	27.34	3.3	pos
10	equiv.	83292	pos	31.61	2.84	pos
1	equiv.	35127	pos	35.31	2.24	pos
0.1	neg	21233	pos	37.96	1.59	pos
0.01	neg	1	neg	45	0.52	neg
0.001	neg	1	neg	45	0.34	neg
	equiv .=f aint	neg: ECL < 350		neg: Rn < 0.84 and Ct > 38.5
	bands on	pos: ECL > 350		equiv .:Rn > 0.84 or Ct < 38.5
	agarose gel			pos: Rn > 0.84 and Ct < 38.5

Automation of Nucleic Acid Extraction

High Throughput Genomic Amplification and Detection

Arbovirus Multiplexing ?

Alphaviruses (WEE, EEE, VEE)

California Serogroup (SSH, LAC)

Flaviviruses

West Nile virus

Dengue, SLE

Career Summary - James L. Gallarda, Ph.D.

Contact : CERB/CBE

James L. Gallarda, Ph.D.
Director, Blood Screening Development
Roche Molecular Systems, Inc.

Career Summary

James L. Gallarda is Director of Blood Screening Development for Roche Molecular Diagnostics, and is responsible for the development of RMD's polymerase chain reaction (PCR)-based diagnostic assays for blood screening.

Gallarda has an extensive background in Research and Development of innovative diagnostic products and systems used to detect infectious diseases, particularly those related to the blood banking industry.

He joined RMD from Mosaic Technologies, Inc., a Boston, Massachusetts-based developer of diagnostic innovations. He served as the company's Vice President of Diagnostics, where his responsibilities included the development of nucleic acid probe-based systems (reagent chemistries and hardware), as well as oversight of the company's quality system and regulatory strategy.

Prior to working at Mosaic Technologies, Gallarda worked with Abbott Laboratories, joining the company in 1989 as a Senior Research Biochemist working in HIV assay development, and eventually becoming scientific advisor for the Abbott Diagnostic Division for its US and European strategy in HIV blood banking. In this role, he was the principal scientist who spearheaded worldwide trouble-shooting efforts related to all Abbott HIV assays.

Gallarda earned his Ph.D. in 1985 from the Department of Microbiology and Immunology at the University of Illinois, Chicago. Subsequent to this he held both Damon Runyon - Walter Winchell and NIH post-doctoral fellowships at Northwestern University, Evanston, IL in eucaryotic gene control.

West Nile Virus Testing Development - Roche Update

James L. Gallarda, Ph.D.
Roche Molecular Diagnostics

West Nile Virus - Canada

Status in North America

• In the U.S.¹
  • Over 3800 cases of West Nile virus disease
  • 225 deaths associated with West Nile virus
• In Canada ²
  • 114 probable cases of West Nile virus disease
  • 84 confirmed cases of West Nile virus disease
  • 2 deaths associated with West Nile virus

West Nile Virus Testing - Logistic Issues

• Target start date for Canada and the U.S. - July 1, 2003
• Timeframe and the associated, necessary resources are unprecedented
• Roche seeking to identify synergies with global automation efforts
• System comprises
  • PCR reagents and controls
  • System hardware
  • System software
• To meet the WNV threat, system features to be discussed
• The timeline is the highest priority. Items to consider:
  • PCR reagents and controls
  • System hardware
  • System software
• Architecture of system to be discussed with stakeholders

West Nile Virus System - Options

• Target System - Fully Automated
  • Mini-pools to be tested
  • Automated sample preparation
  • Kinetic PCR
• Options
  • Built-in flexibility
  • Pre-existing synergies with FDA-licensed COBAS AmpliScreen system components

West Nile Virus System- Requirements

• System throughput must meet testing lab requirements
• FDA initial guidance on sensitivity requirements ( e.g. 100 copies/mL sensitivity to detect 1000 copies/mL in individual samples)
• Compliance to FDA Quality System Requirements
  • Hardware
  • Software
  • Reagents

Preferred System - Fully Automated

Current Sensitivity Performance (< 30 C/mL)

Negative Population Growth Curve

Studies in Progress

• Specificity Studies
  • Analytical Specificity
  • Population from low endemic area
  • Population from high endemic area
• Limit of Detection ( LOD) Studies
• Whole System Failure, Precision, Reproducibility
• Interfering Substances

Next Steps - Discussions with Regulatory Agencies

• Validation in donor screening environment ( multi-site clinical trial)
  • ITA ( Canada) and IND ( U.S.)
  • Role/quality of serologic referee assay: IgM?; IgG?
  • Role/quality of alternate NAT
  • Study design to accommodate screening claims
  • Other claims? ( e.g. donor follow-up?, tissue?)

Next Steps - Discussions with Canadian and U.S. Testing Labs

• Priorities to meet timeline
• Workflow in context of FDA-licensed AmpliScreen system ( HCV, HIV-1)
• Logistics affecting laboratory infrastructure
• Data management
• Sample procurement in context of FDA-licensed AmpliScreen system
• Logistics affecting SOPs, training, validation

Roche Diagnostics - Commitment to West Nile Response

Biography - Dr. Jeff Linnen, Gen-probe

Contact : CERB/CBE

I hold a BS degree in biology from the University of Notre Dame (Notre Dame, IN) and a Ph.D. in Biochemistry from the University of Iowa (Iowa City, IA).

After completing my graduate studies, I was a post doctoral fellow at Genelabs Technologies in Redwood City California, where I identified the first molecular clone of what is known as Hepatitis G virus (HGV). My group then cloned and sequenced the entire genome of HGV. I then held a Senior Scientist position at Ortho Clinical Diagnostics (Rochester, NY), working to develop a PCR assay for hepatitis C virus (HCV). I joined Gen-Probe five years ago and I am currently a Senior Staff Scientist in the Research and Development Group. At Gen-Probe, I have worked in the development of nucleic acid based assays for use in blood screening, including the Procleix HIV-1/HCV Assay (which was licensed for use in the US in February of 2002)and the Procleix Ultrio Assay (an assay for detection of HIV-1, HCV, and Hepatitis B virus [HBV] nucleic acids), which is under development. Most recently, my group has worked to develop a prototype TMA-based assay for West Nile virus.

Procleix^® WNV Assay: Transcription-mediated Amplification Assay for the detection of West Nile virus RNA

January 9, 2003

Jeff Linnen, Ph.D.
Gen-Probe Incorporated,
San Diego, CA

Gen-Probe Incorporated

• Develops and manufactures nucleic acid testing (NAT) products for clinical diagnosis of human diseases and for screening donated human blood
• FDA approvals for more than 50 products that detect a wide variety of infectious microorganisms
• Developed and manufactures FDA-approved blood screening assay for the simultaneous detection of HIV-1 and HCV (marketed worldwide to blood centers by Chiron Corporation)
• Approximately 700 employees

Objectives of the West Nile Virus Assay Development Program

• To develop and manufacture a TMA-based assay for detection of West Nile virus in blood, plasma and organ donor specimens
  • This program will support linked donor-recipient WNV epidemiological studies
  • Blood screening under an IND beginning in the US in summer of 2003.

WNV Assay Development Goals

• Analytical sensitivity: at least 95% detection at 50 copies/mL
• Detection of genetic variants of WNV (e.g Lineage 1, including Kunjin virus, and Lineage 2 strains) with similar sensitivity
• Analytical specificity: > 99.5 %
• Internal Control for validating each reaction
• Chemistry that is essentially identical to that used in the FDA licensed Procleix^® HIV-1/HCV Assay
• Completely compatible with Procleix (semi-automated) and fully automated TIGRISTM instrument platforms

Procleix Semi-Automated System: Assay Protocol

Specimen Processing

Target Capture/Magnetic Microparticle Separation

Viral Lysis

• Treat specimens with heat and detergent
• Release nucleic acid

Nucleic Acid Capture

• Hybridize target sequence to capture probes
• Hybridize capture probe to oligomer sequence bind to magnetic particle

Removal of unwanted specimen

• Apply magnetic field to separate target from residual sample
• Remove residual specimen by washing

Amplification

Transcription-Mediated Amplification (TMA)

• Utilizes two enzymes:
  • Reverse Transcriptase
  • T7 RNA Polymerase
• Amplifies RNA or DNA
• Produces RNA amplicon
• Exponential amplification
  • (> billion fold amplification in less than one hour)
• Isothermal, simplifies automation

Detection

Hybridization Protection Assay (HPA)

• Utilizes Acridinium Ester (AE) labeled probes
• Reaction Steps:
  1. Hybridization
     AE-labeled probe hybridizes to target RNA in solution
  2. Selection
     Label on unhybridized probe is hydrolyzed, label on hybridized probe is protected
  3. Detection
     Label on protected hybridized probe is detected by chemiluminescence

Dual Kinetics Analysis (DKA)

• Used to differentiate Internal Control (IC) signal from target signal
• Utilizes Acridinium Ester (AE) labeled probes with differential kinetics of light-off
• Ortho Fluoro Acridinium Ester labeled probe = flasher probe, hybridizes to IC
• 2'Methyl Acridinium Ester labeled probes = Glower probes, hybridize to West Nile virus amplicon
• ETF Algorithm deconvolutes light-off and calculates each signal

WNV Assay Reagents

WNV specific reagents:

• Target Capture Reagent
• Amplification Reagent
• Probe Reagent
• Internal Control
• Positive Calibrator

Reagents common to other Procleix assays:

• Enzyme Reagent
• Selection Reagent
• Procleix TMA Fluids

Assay Calibrators and Controls

Assay Calibrators

• 3 Replicates of Negative Calibrator
• 3 Replicates of WNV Positive Calibrator

Internal Control

• RNA transcript added in each specimen with TCR
• Detected with Internal Control flasher probe
• Monitors performance of reagents, operator and instrumentation

External Quality Controls

• 1 Replicate of Negative Control specimen
• 1 Replicate of WNV Positive Control specimen

Current Assay Performance

Detection of WNV using Synthetic RNA Transcript

WNV RNA (copies/mL)	N	% detection	95% detection [95% CI]*	50% detection [95% CI]*
600	20	100	7.6 copies/mL [6.1 to 10.6]	3.5 copies/mL [2.5 to 4.5]
200	30	100
60	30	100
20	29	100
6	26	79.3
2	20	43.8
0.3	20	0
0	30	0

^* Probit analysis using SAS

Detection of WNV using CDC Viral Lysate Standard (Lineage 1)*

RNA Dilution	% Detection (N =50)	95% Detection (dilution level)	50% Detection (dilution level)
1 x 10-4	100	2.7 x 10-6 dilution	4.5 x 10-7 dilution
1 x10-5	100
3.2 x 10-6	96
1 x 10-6	76
3.2 x 10-7	38
Negative Control	0

^*Provided by Dr. R. Lanciotti

Detection of WNV Lineage 2 (Ugandan strain): Dilution of 10,000 C/mL member (QWN701.03) from the BBI Quality Control Panel

Copies/ mL*	N	TMA Formulation #1	TMA Formulation #2	TMA Formulation #3
300	5	100%	100%	100%
100	10	100%	100%	100%
30	10	100%	100%	100%
10	10	90%	100%	100%
0	5	0%	0%	0%

^*Quantitation based on BBI Taqman assay

Detection of West Nile Virus (Lineage 2) in the BBI Quality Control Panel

Panel Member	West Nile Virus RNA Copies/mL	TMA Formulation #2	TMA Formulation #3
QWN701.01	100	Positive	Positive
QWN701.02	0	Negative	Negative
QWN701.03	10,000	Not Tested	Not Tested
QWN701.04	30	Positive	Positive*
QWN701.05	1,000	Positive	Positive
QWN701.06	300	Positive	Positive
QWN701.07	100	Positive	Positive
QWN701.08	0	Negative	Negative
QWN701.09	30	Positive	Positive
QWN701.10	1,000	Positive	Positive
QWN701.11	100	Positive	Positive
QWN701.12	10,000	Not Tested	Not Tested
QWN701.13	0	Negative	Negative
QWN701.14	30	Positive	Positive**
QWN701.15	300	Positive	Positive
GP Negative Control	0	Negative	Negative
GP Negative Control	0	Negative	Negative
GP Negative Control	0	Negative	Negative
GP Negative Control	0	Negative	Negative
GP Negative Control	0	Negative	Negative

^*low positive; signal-to-noise = 14.3

^**low positive; signal-to-noise = 12.3

Conclusions

• Analytical sensitivity for detection of WNV to date:
  • 95% detection of CDC standard at 2.7 x 10-⁶ dilution
  • 50% detection of CDC standard at 4.5 x 10-⁷ dilution
  • 95% detection of WNV transcript at 7.6 copies/mL
  • 50% detection of WNV transcript at 3.5 copies/mL
• Demonstrated sensitive detection (down to 10 c/mL) of West Nile virus Lineage 2 isolate (genetic variant of the US strain)
• Analytical sensitivity suggests feasibility of pooled testing (pool size of 16).

Acknowledgments

This project is funded in part with federal funds from the National Heart, Lung and Blood Institute under Contract No. NHLBI-HB- 07148

Biography - Dr. Peyton S. Metzel

Contact : CERB/CBE

Received his PhD from the University of Illinois at Urbana-Champaign in 1979 in Cell Biology & Virology. Over the ensuing twelve years, Dr. Metzel assumed positions of increasing responsibilities in diagnostics development at Abbott, Ciba Corning and Amersham. In 1991, he joined Baxter's Fenwal Division as Director, Pathogen Inactivation. There he led a multidisciplinary team, evaluating various technologies for their use in pathogen inactivation of blood products.

In 1993, Baxter signed a development agreement with Cerus Corporation. Dr. Metzel successfully managed a multifaceted team, guiding the platelet and FFP pathogen inactivation programs through pre-clinical development, clinical trials, and regulatory submission. In 2001, he assumed the position of Director of Scientific Affairs, where he is responsible for presentations of INTERCEPT and scientific assessment of new technologies.

Demonstration of Inactivation of WNV and Other Flaviviruses- Pathogen Inactivation of Blood Components

Peyton S Metzel, PhD
Baxter Healthcare, Fenwal Division

January 9, 2003
Ottawa, Canada

Confidential

Outline

• Baxter
• Helinx Technology
• Inactivation of Pathogens
• Inactivation of Flaviviruses
  • Hepatitis C Virus (HCV)
  • Bovine Viral Diarrhea Virus (BVDV)
  • West Nile Virus (WNV)
• Conclusions

Baxter International Inc.

• Global medical products and services company
• Focus on critical therapies for life-threatening conditions
• Over 50% of sales from outside United States
  • Represented in more than 100 countries
• Employs 48,000 people worldwide
• Sales $7.7 billion (2001, U.S.)
• Invests over $1 million per day in research and development
• Corporate headquarters located in Deerfield, Illinois

Baxter Corporation

• Canadian subsidiary of Baxter International Inc.
• Canadian headquarters in Mississauga, Ontario
  • Manufacturing facilities in Alliston, Ontario; Sherbrooke, Quebec
• Employs nearly 1,000 people
  • 550 in manufacturing facilities
• Sales over $375 million (2001)

Helinx Technology

• Pathogens and leukocytes require nucleic acids for replication
• Blood components do not require nucleic acids for therapeutic function
• Helinx technology targets and modifies nucleic acids to prevent replication of viruses, bacteria, protozoa, and leukocytes
• Helinx technology for blood components
  • Platelet: Amotosalen HCL (S59)
  • Plasma: Amotosalen HCL (S59)
  • RBC: S-303

Mechanism of Action

INTERCEPT Platelet System

INTERCEPT Plasma System

INTERCEPT RBC System

Study Design for the Validation of Pathogen Inactivation

• Full-sized, therapeutic units of platelet concentrate, plasma, and RBC were used.
• Each unit was spiked with ~10⁶ infectious units/mL or with highest titered stocks available.
• The contaminated units were treated with
  • Platelets/Plasma: 150 µM amotosalen and 3 J/cm² UVA
  • RBC: 200 µM S-303
• Inactivation kinetics were measured.
• The infectivity of each pathogen was assayed using culture methods or animal models.

Inactivation of Currently Tested Pathogens

Log Reduction Log Reduction

	Platelets	Plasma	RBC
HIV-1, cell-free	> 6.2	> 5.9	> 6.5
HIV-1, cell-associated	> 6.1	6.4	> 6.5
HIV-1, clinical isolate	> 3.4
HIV-2, clinical isolate	> 2.5
HBV (Human MS 2)	> 5.5	> 4.5
HCV (Human Hutchinson Strain)	> 4.5	> 4.5
CMV	> 5.9
HTLV-I	4.7
HTLV-II	5.1
Treponema pallidum* (Syphilis)	6.8 - 7.0

^* Tested in animal infection assays

Flavivirus

• Yellow Fever
• Japanese encephalitis
• St. Louis encephalitis
• Border Disease
• Hog cholera
• Dengue
• Usutu
• Hepatitis C
• Bovine viral diarrhea
• West Nile Virus

Inactivation of HCV in Platelets Study Design

• 10^4.5 CID of the well-characterized Hutchinson strain of HCV were spiked into 3 full-sized apheresis platelet concentrates in 35% plasma/65% PASIII and treated with 150 µM amotosalen and 3 J/cm² UVA.
• Each unit (300 mL) was infused into a seronegative chimpanzee, which was followed for 6 months for development of hepatitis as well as molecular and biological markers of HCV infection.
• Infection of Hutchinson strain of HCV in chimpanzees has been shown to be uniform and consistent.

Inactivation of HCV Infectivity in Platelets Results

Inactivation of BVDV Study Design

• Approximately 10^5-6 pfu/mL of BVDV (strain NADL, ATCC) were spiked into full-sized platelet, plasma, or RBC units.
• The contaminated units were treated with
  • Platelets/Plasma: 150 µM amotosalen and 3 J/cm² UVA
  • RBC: 200 µM S-303
• The viral titer in a sample was measured using a plaque assay on bovine turbinate cells.

Inactivation of BVDV Infectivity Results

Log Reduction

	Platelets (N=4)	Plasma (N=4)	RBC (N=4)
BVDV	> 6.0	> 6.0	> 7.3

Kinetics of BVDV Inactivation

UVA Dose (J/cm2)	BVDV Titer (log pfu/mL)	Log-Reduction (N=4)	Volume Assayed
0	4.8	0
0.5	< -1.5	> 6.3	30 mL (No virus 4/4)
3	< -1.7	> 6.5	49 mL (No virus 4/4)

Amotosalen Dose Response of BVDV Infectivity

Inactivation of WNV Viral Inoculum

• This study was conducted in collaboration with Dr. Kristen Bernard of the New York State Department of Health.
• The viral inoculum was prepared from BHK-21 cells infected with a full-length infectious clone of WNV.
• The parental strain of WNV (lineage I) was isolated from the epicenter of New York City during the 2000 outbreak.
• The infectivity and virulence of the cloned virus and the parental virus are similar.
• The plaque morphology of the cloned WNV is indistinguishable from the parental virus.
• Working viral stock: 1 x 10⁸ pfu/mL

(Shi et al, J Virol. 76:5847-5856, 2002)

Inactivation of WNV Study Design

• Approximately 10⁶ pfu/mL of the cloned WNV were spiked into full-sized units of platelet concentrate or RBC and treated with:
  • Platelets: 150 µM amotosalen and 3 J/cm² UVA
  • RBC: 200 µM S-303
    
    
• The titer of WNV was measured using a plaque assay on Vero cells.

Inactivation of WNV Infectivity Preliminary Results

	Volume treated (mL)	Initial WNV Titer (pfu/mL)	Post - treatment WNV Titer (pfu/mL)	Log - Reduction (N=2)	Comments
Platelets	300	5.4 x 105	< 1	> 5.7	No recoverable virus in 1 mL in 2 of 2 experiments
RBC	300	9.1 x 105	< 1	> 6.0	No recoverable virus in 1 mL in 2 of 2 experiments

Advantages of Pathogen Inactivation

• Proactive vs. reactive strategy (testing)
• Independent of donor testing
• May alleviate need for new tests
• Minimizes impact of new infectious agents

INTERCEPT Program Status

Conclusions

• Helinx technology inactivates a broad spectrum of viruses, bacteria, protozoa, and leukocytes in platelets, plasma and RBC.
• Preliminary results demonstrated inactivation of high levels of WNV in platelet concentrate and RBC components.
• Both amotosalen and S-303 are effective against WNV.

Bacterial Inactivation in Platelets

Gram-Negative	Log Inactivation
Escherichia coli	> 6.4
Serratia marcescens	> 6.7
Klebsiella pneumoniae	> 5.6
Pseudomonas aeruginosa	4.5
Salmonella choleraesuis	> 6.2
Yersinia enterocolitica	> 5.9
Enterobacter cloacae	5.9

Parasite Inactivation in Platelets Parasite Inactivation in Platelets

Parasite	Disease	Log Inactivation
Treponema pallidum	Syphilis	> 4.6
Trypanosoma cruzi	Chagas	> 6.0
Borellia burgdorferi	Lyme	Planned
Plasmodium falciparum	Malaria	Planned
Babesia microti	Babesiosis	Planned

Leukocyte Inactivation

• Inactivates > 5.4 logs of T-Lymphocytes (LDA assay)
• Inhibits cytokine synthesis during platelet storage
• Prevents Transfusion-Associated Graft-Versus- Host Disease in a murine transfusion model

INTERCEPT Red Cell System Bacterial Inactivation Data

Gram Positive	Log Inactivation
Listeria monocytogenes	> 7.0
Staphylococcus aureus	> 5.2
Staphylococcus epidermidis	> 6.9
Deinococcus radiodurans	> 6.0

Toxicology Studies for INTERCEPT Systems Under Development

Canadian Contact

Nicole Faucher
Business Unit Manager
Fenwal Canada
800 387 8399 x 6624
fauchen@baxter.com

Biography of Dr. R. Peterson (Chair)

Contact : CERB/CBE

Dr. Peterson received an M.D. degree and a Ph.D. in Pharmacology from Yale University in 1974, having completed the National Institutes of Public Health sponsored Medical Scientist Training Program at that university. He was a resident in pediatrics at the Yale-New Haven Hospital until 1976 at which time he became a postdoctoral fellow in Clinical Pharmacology and Neonatology at the University of Colorado. He subsequently joined the Department of Pediatrics at the University of Colorado as Assistant Professor, where he was Director of the Section of Pediatric Clinical Pharmacology. In 1983, Dr. Peterson joined the Departments of Pediatrics and Pharmacology at the University of Ottawa, Faculty of Medicine as Associate Professor and Medical Director of the Ontario Provincial Poison Information Centre at the Children's Hospital of Eastern Ontario. In 1987 he became Director of the Children's Hospital Research Institute. He became Professor of Pediatrics and Pharmacology in 1989, and in 1990, Chairman of the Department of Pediatrics and Pediatrician-in-Chief. He has authored numerous papers/chapters in pediatric clinical pharmacology/toxicology and is qualified in hyperbaric medicine. Dr. Peterson completed a Master's of Public Health in the Department of Health Policy and Health Care Management at Harvard University School of Public Health in 1996. He joined the Therapeutic Products Programme, Health Canada, as Associate Director General in January 1999 and in July 2000, became the Director General of the Therapeutic Products Directorate.

Eleftherios C. Vamvakas, MD, PhD

Contact : CERB/CBE

Eleftherios C. Vamvakas, MD, PhD, is Executive Vice President, Medical, Scientific, and Research Affairs, Canadian Blood Services, and adjunct professor of pathology and laboratory medicine, University of Ottawa Faculty of Medicine. He earned his MD degree from the National University of Athens, Greece. He also received an MPH in epidemiology from Harvard University, an MPA in health services management, an MPhil, and a PhD in health policy analysis, all from New York University. His postgraduate training was in anatomic and clinical pathology at the New York University Medical Center and in transfusion medicine at the Mayo Clinic.

Until recently, Dr. Vamvakas was director of the Blood Bank and Transfusion Service of the New York University Medical Center and associate professor of pathology at the New York University School of Medicine. Previously, he was chief of the Pathology and Laboratory Medicine Service of the New York Department of Veterans Affairs Medical Center, and assistant director of the Blood Transfusion Service of the Massachusetts General Hospital and assistant professor of pathology at Harvard Medical School.

Dr. Vamvakas' research activities include clinical investigations of the immunomodulatory effects of allogeneic blood transfusion, applications of meta-analysis to pathology practice, and population-based studies of the epidemiology of blood transfusion. He authored the book Evidence-Based Practice of Transfusion Medicine, and co-edited the book Immunomodulatory Effects of Blood Transfusion. He has also published more than 80 journal articles and book chapters.

Canadian Blood Services' Response To West Nile Virus (wnv) As A Threat To The Safety Of The Blood Supply

West Nile Virus Regulatory Consultative Workshop

Session III: West Nile Virus Operations Perspective

January 9, 2003

Summer 2002 Mosquito-borne Epidemic Of wnv In Canada

Summer 2002: Information in the media and the Health Canada web site on mosquito-borne WNV infection of:

• humans in Ontario,
• birds, mosquito pools, and/or horses in Ontario, Saskatchewan, Manitoba, and Nova Scotia.

September 6, 2002: MMWR report on WNV transmission by solid organ transplantation.

Laboratory Testing Of Humans For wnv Across Provinces Of Canada, Summer 2002

Samples from "SUSPECTED" cases of viral encephalitis or meningitis tested for WNV, but stringency of definition varied:

• FROM any febrile illness with associated neurologic manifestations,
• TO a requirement for CSF pleocytosis c/w viral meningoencephalitis.

If antibodies to flaviviruses demonstrated, case designated as "PROBABLE". If WNV genome or antigen or WNV IgG or IgM antibody demonstrated, case considered CONFIRMED.

CBS Communication To The Chief Medical Officer Of Health Of Ontario (september 5, 2002) And The Other Provinces (september 10, 2002)

• Request for the names of all persons with probable or confirmed WNV infection:
• to search the CBS donor database to determine whether any of these persons had made a recent blood donation.
• Request for information whether any probable or confirmed cases had received a blood transfusion recently:
• to identify any transfusion-transmitted cases of WNV infection by testing blood donors for WNV.

Ontario Public Health Department Communications To cbs

Numbers of probable and confirmed HUMAN cases:

• As of September 17: 17 (14 probable; 3 confirmed)
• As of October 16: 81 (55 probable; 26 confirmed)
• As of November 14: 144 (95 probable; 49 confirmed)
• As of December 12: 191 (114 probable; 77 confirmed)

To date, no person with probable or confirmed WNV infection has been found to have been a recent blood donor.

Possible Transmission Of wnv Infection Through Transfusion In Ontario - - 1

• Information received by CBS from the hospital transfusion service (November 8) and the Ontario public health department (November 11).
• Between August 1 and September 2, this patient had received transfusions of red cells and platelets from 31 donors.
• There were no remaining companion products from these donations in inventory, although 10 units of recovered plasma from these donors had been sent to Bayer for fractionation.

Possible Transmission Of wnv Infection Through Transfusion In Ontario - - 2

• CBS is in the process of contacting the 31 donors and requesting blood samples for testing for WNV.
• Should 1 (or more) of these donors test positive for WNV:
• Recipient tracing and notification will ensue.
• This will become the first confirmed case of transmission of WNV by transfusion in Canada.

Communications From Other Provincial Public Health Departments To cbs About human Cases

• British Columbia: No cases of WNV meningoencephalitis.
• Alberta: Two confirmed cases of WNV meningoencephalitis in Alberta residents:
• one presumed to have been acquired in Louisiana or Texas;
• one presumed to have been acquired in Ontario.
• Saskatchewan: No confirmed case of WNV infection.
• Manitoba: No confirmed or probable cases of WNV infection.
• New Brunswick: No cases of WNV encephalitis/meningitis.
• Nova Scotia: No cases of WNV.
• Newfoundland: No cases of WNV meningoencephalitis, suspected or reported.

Documentation Of wnv Transmission By Transfusion And cbs Responses - - 1

By mid-October, the CDC had confirmed transmission of WNV by transfusion in 6 transfusion recipients, and transmission of WNV by transfusion was considered virtually established.

CBS responses:

October 16: Customer letter entitled "Information for health care professionals with respect to the apparent transmissibility of WNV by blood transfusion".

November 8: Directive on "Actions to be taken on reported cases of WNV".

Documentation Of wnv Transmission By Transfusion And cbs Responses - - 2

End of November: West Nile Virus Steering Committee appointed with a mandate to:

• examine all data regarding transmission of WNV by transfusion in Canada, and
• make recommendations for reducing this risk.

December 4: First meeting of the WNV Steering Committee to examine the possibility of withdrawal of extant frozen products collected in areas of the country that had reported human cases during the epidemic of WNV infection.

Rationale For cbs' Withdrawal - - 1

• Since transmission of WNV infection by transfusion had been established, there had to be some infectious units amongst the inventory of frozen products collected during the months of the human epidemic.
• It was inappropriate to postpone taking action for the removal of these units past a date when CBS management could be reasonably confident about its ability to replace the withdrawn inventory.

Rationale For cbs' Withdrawal - - 2

• The ratio of WNV cases in Ontario vs. the U.S. was approximately equal to the ratio of the total population of Ontario vs. the U.S.
• Thus,during the months of the human epidemic in Ontario:
• the risk of transmission of WNV by transfusion was approximately equal to that in the U.S., and
• any measures taken in Ontario to protect the safety of the blood supply should, at a minimum, match those in the U.S.

Scope Of Cbs' Withdrawal - - 1

Should the withdrawal be limited to units collected in Ontario or should it also encompass provinces that had reported avian and equine (but not human) cases? When no human cases are reported in a province, there could be 150 undiagnosed cases of WNV infection in that province. (If it takes a case of meningoencephalitis to trigger a work-up for WNV infection; AND
only 1 in 150 infected humans develops meningoencephalitis, 150 undiagnosed cases of WNV infection may occur in a province before a case of meningoencephalitis emerges.)

Scope Of cbs' Withdrawal - - 2

Of 150 undiagnosed cases of WNV infection, 120 (i.e., 80%) can be asymptomatic, and can present as blood donors. If 3% of Canadians make a blood donation each year, as many as 4 individuals (i.e., 3% of 120 in a province that reports no human cases) can present as blood donors. Because viremia lasts for 6.2 days on average, 4 infected donors can contribute only 25 days of viremia. These 25 days are spread over a risk period of 4 months (July to October for the north of the U.S. and Canada), so that one can reasonably expect only 1 viremic donation in a province that reports no human cases.

Scope Of cbs' Withdrawal - - 3

Such an estimate of 1 viremic donation per province is not the most likely estimate of risk for provinces that reported no human cases but had confirmed avian and/or equine cases. The most likely estimate of risk for these provinces would be 0 viremic donations.

In the absence of any human cases, a reasonable assumption to make is that WNV infection has not yet "spilled over" from birds and animals to humans. (Significant proliferation of the virus in other species precedes the onset of the first human case, but human cases do not necessarily follow avian and/or equine cases.)

Scope Of cbs' Withdrawal - - 4

Even if the correct estimate of risk (for provinces that had avian and/or equine but no human cases) were 1 viremic donation per province, such a risk would fall within the range of risks considered to be "acceptable".
Therefore:

• The scope of the CBS withdrawal should be based on data from human cases recorded by provincial health departments.
• In the event that CBS inventory might allow expansion of the withdrawal beyond the scope of a withdrawal based on human cases, the possibility of expanding the withdrawal based on avian and/or equine cases could be considered.

Inventory impact Of A cbs Withdrawal Of Frozen Components Collected In Ontario Between June And October, 2002

Data obtained (between December 4 and December 11) on the proportion of components that would be affected by a withdrawal based on human cases of WNV infection:

	July - Sept	July - Oct
FFP	4.2%	8.0%
AFFP	2.1%	2.3%
Cryoprecipitate	8.4%	21.3%
Cryosupernatant	8.6%	15.1%

December 12, 2002 U.s. Withdrawal Of Products Collected In Each State That Had Reported human wnv Cases In 2002

• Withdrew frozen products collected during a period:
  • starting 7 days before the onset of symptoms in the first reported case of WNV meningoencephalitis in that state; and
  • ending 7 days after the onset of symptoms in the last reported case of WNV meningoencephalitis in that state.
• For states contiguous to Ontario, the last reported case of WNV meningoencephalitis was:
  • October 20, 2002 in New York State; and
  • October 25, 2002 in the State of Michigan.

December 12, 2002 cbs Withdrawal Of Products Collected In Each Province That Had Reported human Cases In 2002

• Withdrew products collected in Ontario between June and October, 2002.
• Because there appeared to be a reasonable likelihood that those products could be replaced by products collected:
  • outside Ontario,
  • and/or after October, 2002.

Impact Of cbs' Withdrawal On Blood Center And Hospital Inventories

Based on data available to CBS on December 20, 2002, CBS management was confident that all quarantined components of groups O, A, or B could be replaced.

Quarantined components of group AB might not be replaced in their entirety until mid-January 2003.

On December 20, 2002, CBS issued a customer letter on how to prioritize the use of quarantined components, based on:

• the clinical diagnosis of the prospective recipients, and
• the month of collection of each quarantined component.

Impact On Inventory Of An expanded cbs Withdrawal That Would Include Saskatchewan, Manitoba, And Nova Scotia

• Such an action would destabilize inventories, and might create significant shortfalls.
• Given CBS' assessment of a risk of 0-1 viremic donation (per province that had not reported human cases of WNV infection, despite recording avian and/or equine cases), CBS management decided on December 20, 2002:
  • not to expand the withdrawal to such provinces, but
  • consider the possibility of a limited withdrawal should a human case arise in one of these provinces.

CBS Plans For Reducing The Risk Of Transmission Of wnv Infection By Transfusion In The Summer Of 2003

CBS will be ready to implement blood donor screening for WNV under IND when a suitable assay becomes available from Roche, GenProbe, or other assay manufacturer.

CBS is also considering contingency plans in the event that an assay is not available or does not have adequate sensitivity. These include:

• stockpiling plasma collected during the winter months for use during the summer months;
• other, tentative contingency plans to be discussed during the facilitated sessions.

Doctor Gilles Delage - Short Resume

Contact : CERB/CBE

Doctor Gilles Delage, a specialist in medical microbiology, started his career at Hôpital Sainte-Justine where he later created the infectious diseases consultation service. Afterwards, he worked for the Canadian Red Cross Society - Transfusion Centre first as Medical Assistant and thereafter as Assistant Medical Director. Doctor Delage then joined the Laboratoire de santé publique du Québec's team as Scientific Director. In August 3>000, he joined Héma-Québec; he is presently Senior Director - Medical Affairs.

Doctor Delage has been involved in many committees, such as the National Advisory Committee on Immunization, the Editorial Committee of the Canadian Infectious Diseases Journal, the Comité sur l'immunisation du Québec, the Expert Working Group on Blood Standards of Health Canada's Biologics and Genetic Therapies Directorate, as well as the Comité québécois sur l'approvisionnement, la gestion et la distribution du sang. Furthermore, he is the president of the Technical Committee on Blood and Blood Products of the Canadian Standards Association.

He is the author of 130 scientific publications, 94 presentations and 8 book chapters. During his career, he did research on the prevention of perinatally acquired hepatitis B virus through immunization, on the hepatitis C virus infection in blood donors, and on post-transfusion infections.

Héma-Québec and the West Nile Virus

WNV Activity in Québec 3>003>

• Human cases:
  • 7 confirmed
  • 3> probable
  • 15 under investigation
• Date of first case: July 3>, 3>003>
• Date of last case: September 3>9, 3>003>
• Peak incidence: end of August 3>003>
• All cases found in the southwestern part of the province (Montreal, Laval, Montérégie, and southern part of Laurentides and Lanaudière)

WNV Activity in Québec 3>003>

• Infected dead birds: 139
• Regions affected: all except Gaspésie/Iles de la Madeleine and Northern Quebec
• Date of discovery of the first infected bird varied according to region - from June 13 to September 13>
• Infected horses: 3
• All found in Montérégie

Actions taken to date

• Product recall following post-donation information
• Deferral of suspected, probable, or confirmed WNV-infected donors
• Traceback in cases of suspected posttransfusion infection

Product Quarantine and Recall

• Quarantine and recall of frozen products collected between June 3>5 and October 6, 3>003> from donors residing in the following regions:
  • Montréal-Centre;
  • Laval
  • Montérégie
  • Laurentides and Lanaudière (southern sectors)
• Based on the occurrence of human cases (first case 03>/07, last case 3>9/09)
• 963>0 frozen products identified
• 589 in stock at HQ
• 9031 sent to hospitals
• 704 retrieved from hospital inventory
  • 3>78 FFP
  • 355 cryos
  • 71 cryosupernatants

Impact of withdrawal

	Optimal inventory	Actual inventory (16/13>/03>)	Products retrieved (hosp.+HQ)
FFP	1500	3>739	3>85
CRYOS	500	860	373>
CRYOSUP	1700	1900	636

Product Quarantine and Recall (Cont'd)

• Expansion to all regions was considered
• Risk period in each region was defined as interval between date of onset of the first dead bird and October 6
• 5416 additional products needed to be targeted
• Not implemented because of the potential impact on supply (December 3>0th)

Plan of action for next season

Plan A:

• Increase stocks of frozen products before the beginning of WNV season
• Introduction of a commerciallyproduced NAT test for systematic screening of all the blood supply during the WNV 3>003 season

Plan A Increase stocks of frozen products before the next WNV season

• Action plan to be developed in early January 3>003
• Needs to be implemented soon in order to maximize the window of opportunity

Plan B: (if plan A cannot be implemented):

• Development of an in-house NAT test for partial screening of the blood supply (depending on analytical sensitivity of the test)

Plan B In-house NAT test development

• Progress to date:
  • reagents and protocols obtained from the Winnipeg lab (excellent collaboration of Mike Drebot)
  • Preliminary experiments demonstrate successful amplification of viral material
• Next steps:
  • Fine tuning of the test
  • Development of an Elisa-based detection step
  • Determination of test sensitivity
  • Bioproduction
  • Test validation

Other options

• Collection of blood in areas where there is no reported WNV activity during the summer. Unrealistic for two reasons:
  • « early » WNV activity expected in most if not all Quebec regions next season
  • the logistics of changing blood drive schedules difficult if not impossible: rapid ajustments to surveillance information necessary

Future perspectives

• Pathogen reduction?
• Immunoglobulin prophylaxis?

Biography of Dr. B. Casley (Chair)

Contact : CERB/CBE

Bill Casley is a research scientist in the Molecular Biology Division, at the Centre for Biologics Research in the Biologics and Genetic Therapies Directorate of Health Canada, in Ottawa. He joined Health Canada in 1992 and developed a research program in pharmacogenetics, in recognition of the increasing impact of this area on the discovery, development and marketing of new therapies.

Dr. Casley's main research interest is the genetic complexity of drug metabolism, using genomic analysis in mice to identify novel determinants of pharmacogenetic variation. He is also involved in collaborative pharmacogenomics research with scientists in Canada and the United States involving aboriginal populations of the Canadian north.

Dr. Casley is also active in the area of applied research to ensure the safety of blood -derived therapeutics. He was a member of the expert working group which drafted the General Method for Nucleic Acid Testing for the European Pharmacopoeia and is currently a member of the World Health Organization working group for the Standardization of Nucleic Acid Testing for Viral Contaminants in Blood and Blood Products. Dr. Casley also participates in several international collaborative studies on methodologies for viral screening.

Red Breakout Group: Question#1- What are the key messages to be communicated to the public about WNV risk? About transfusion and transplantation risks?

Contact : CERB/CBE

• Consistent messages across stakeholders and country;
• Honest as to what risk is - there is a risk;
• Factual - simple and clear;
• Admit what we do not know;
• Put in context with other risks;
• Determine who the target population is;
• Physician is part of targeted population;
• Various audiences;
• Physicians need to be prepared to explain risk and options;
• Use numbers (not/vs. high-low);
• Be wary that the numbers are continuously changing;
• Speak the truth;
• Compare risk of taking blood vs not taking it;
• Know agent is transmissible by blood - offer assurance of what is being done (risk comm.);
• How big is the risk needs to be communicated;
• Be clear on which blood products are effected and when they pose a risk;
• Messages on real risk needs to be clear (always a risk);
• Cannot expect to have a 0% risk;
• Educate public on real risk and prevention;
• Integrate communication into public health early;
• Risk is different for different groups - choice is important;
• Reeducation of blood donors - what donors need to do;
• Inform/educate media so they understand;
• Develop a communications strategy - appropriate message at appropriate time;
• Media needs substantial numbers, facts to be filtered down to the public;
• Keep message of need to donate blood;
• Put in perspective message that blood system is one of the safest in the world, however...;
• Communications will be different until screening test is available;
• Involve public health support;
• Alert public early (clear messages)
• Explain risk difference from HIV
• Communicate transplantation risks as well;
• If you had WNV and recovered, you can donate (plasma may in fact be helpful);
• Clear messages regarding geographical location and seasonal variation;
• For particular blood banks, what is being done;
• Communicate consistency with what is being done internationally
• WNV not as devastating a disease as HIV or others
• Message on modes of transmission
• Message to grassroots organizations (churches, hiking groups, gardeners, dishwashers);
• Informed consent form (receiving) needs to include information on WNV risk (if no screening test);
• Regular updates by consistent spokesperson (press/media updates) using various mechanisms (e.g. website, media);
• Communication cost of handling risk of WNV in blood system
• Risk communications on WNV to public not to be diluted with other risk issues (dehydration, sunstroke/burn, etc.);
• Key message to donors? - report illness/fever;
• Two messages if not test - risk different;
• Avoid statistics - changing and confusion.

Common Messages/Themes:

1. Truth/accuracy/consistency;
2. Tailoring communications to targeted audiences/regions;
3. Timeliness;
4. Education and support;
5. Need for partnerships (NGOs, F/P/T, health professionals, etc.);
6. Maintain confidence in blood system while acknowledging problems.

Green Breakout Group: Question#2- What strategies should be considered to reduce risk of WNV transmission through transfusion or transplantation? Pros and Cons considered for each strategy.

Contact : CERB/CBE

• DNA testing of donation samples - issues, timing, type, con. availability, cost;
• Developing serology testing particularly organ donors;
• Stockpiling "winter" frozen products and use in summer seasonal collection;
• Another source of human blood, non endemic importing;
• Quarantine (traceability) to see results of testing or if donor ill;
• Enhance donor participation in non-endemic areas;
• Surveillance (human and animal);
• Donor questionnaire modification to elicit response on WNV and encourage symptom reporting;
• Develop contingency plan for limited (time, sample) testing;
• Define populations at high risk of complications;
• Availability of diagnostics testing for general population for physicians;
• Trace back and look back system (for WNV and others);
• Personal protection for mosquito bites for general population;
• WNV vaccine;
• Classification of inventory according to risk - region, season;
• Augment routine WNV reporting to include history of transfusion - BCB of products;
• Inactivation of organisms;
• In-house testing short term;
• Focus on eradication of mosquito breeding grounds;
• Optimal use of blood products;
• Ask winter donors about travel;
• Anti-viral treatment - prophylactic - symptomatic;
• Activate post donation surveillance;
• Research on artificial blood;
• Fund EPO national
• Antibody testing to identify immune donors;
• Vaccination of recipients;
• Vaccination of donors;
• Vaccinate pre-transplant;
• Rapid testing of tissues;

PROS	CONS
Effective - Only one doable	Availability
Builds on existing technology	Cost/Effectiveness
Applied as multiplex test	Time to implement
Test only part of inventory	Specific to flaviviruses
Selective donors/recipients	Time for turnaround
	Lack of efficacy in transplantation vs transfusion -> timing?
	Time for testing
Better than nothing	Sensitivity -> single sample testing
	Slow (down) sensitivity donor ab(-) when viemic & ab + after donation
	Limited info - how long does titre last?
Inexpensive???	Only for frozen products
Safe product	Limited storage, build rent storage space (divert summer stock, supply management)
Build up and taylor stock
Easier to get donors other than in summer
Focus resources $	May miss something
	Cost
	Combine with another strategy
Rapid, point-of-care testing	Needs development
	Not linked to trans/trans combine with other strategy
	Need prioritization of testing
Reduce mosquito and presumable incidence	Not feasible
	No control
	Effectiveness
	Chemicals
	Environment
Short term Solr	Global warming
WNV infection wrt trans/trans opportunity for altruistic effort from region to region - good communication	How accessible
	$ for collection
Somewhat effective	Miss asymptomatic cases (80%)
Screen out mosquito bites?	Lose donors
Test question	Inappropriate conclusions - memory of bites, bites don't necessarily mean infection
Easy and cheap
Useful for high risk populations, recipients	Not available for humans yet
	Efficacy
	Research needed
	Long term
	Not enough info - don't even know how natural immunity protects
Targets more than 1 pathogen will decrease number of deaths due to WNV inf.	Not fast
Reduce number of testing	Long term strategy
	$ so far
	Long term safety
	Need for increased donors/donations
Simple, cheap	Compliance
Prevents infection for all types of mosquito infection	Need more information for long term effect of DEET (Ca) danger of children's misuse
	Repeat application needed
	Prevent natural immunity

Blue Breakout Group: Question#3- What processes can be put in place to facilitate development of testing for WNV?

Contact : CERB/CBE

Group 1

• Moving the summer further next year;
• Harmonisation of requirements (Regulatory - USA & Canada);
• Standardized viral panels for distribution to manufacturer and testing sites;
• Common requirements for quality for USA and Canada;
• Data submission requirements;
• Appropriate allocation of financial resources for the testing;
• Legal issues

Group 2

• No fault compensation put in place (politically) in order to motivate the government of the time to take action;
• Immediate and continued communication between Regulators and test developers;
• Identification and training of personnel at the testing sites to prepare for testing (Blood Operators);
• Phase in implementation;
• Fast track the licensing of the testing;
• Allocation of financial resources - provincial;
• Early identification of test sites in high titre areas - endemic areas;
• Serum bank - establish to store samples;
• Follow-up system for those testing positive;
• Surveillance system - to pick up the positive that were missed;
• General diagnostic testing available - Provincial Health;
• Requirements of confirmatory testing - should be kept minimal;
  • culture (NAT - positive, IgM - negative);
  • (there is no confirmatory testing);
• Continued communication for implementation and to meet the time lines;
• Other countries dealing with WNV;
  • Role of HC labs in developing the test;
  • Funding;
  • Personnel;
• Quality control;
• Serum bank - NAT positive (Canada);
• Withdrawal of FFP - not feasible with Canada (Q);
• Testing of (uparrow).

Group 3

• Communication between the Blood Operators and the Manufacturer to prepare the submission to the Regulators;
• Prioritize the Review of the submission for Blood and Medical Devices;
• Joint Reviews - USA & FDA;
• De-centralize the testing;
• Encourage the Regulators to drop the p2y test requirement;
• Implementation of the testing;
  • Collaboration between the BOs;
  • Time frame short between approval of test and availability;
  • Rolling submission;
  • Exp. Review (HCV NAT - Jan-Oct);
  • Audit the site - post implementation;
  • Simplify the process;
  • USA-FDA - App. Based on SOP's;
• Human resources dedicated to special issues;
• Pre-planning with the Regulators with terms of requirements - (validation);
• Collaboration;
• On-going communication;
  • Not enough Medical Technicians within Canada to do the testing;
  • Ind. - view of point - continual ongoing feedback - already happened;
  • Relaxation of requirement - Quality;
• Development of testing - includes implementation.

THEMES:

• Resources
  • Human
  • Medical Technicians
  • Red. Test
• Communication
  • Pre-planning
  • Continued and on-going
• Fast tracking Reviews
  • Relax regulatory requirements
  • Joint Review
  • Rolling
  • Priority
• Parallel planning
  • Regulators
  • Ind.
  • Operators
• Collaborative R & D agreement ASAP
• BO's make decision now on which test
• Provincial buy-in

Yellow Breakout Group: Question #4 - What measures should be considered to reduce risk if tests for WNV are not available?

Contact : CERB/CBE

Donor Related Issues

• Screening - additional specific? (Insect bites, rash, travel to endemic areas, symptoms);
• Post donation?
  • Educational material,
  • 5-day follow-up;
• Deferral of donors reporting as un well - for a period e.g one month;
• Pedigree donors from immune population;
• Informed consent for recipients.

Alternatives to Testing

• Stockpiling
  • Seasonal adjustment of collection;
  • Collection from non-endemic areas;
  • Triage/policy of use for stockpiled components;
• SD Plasma;
• Autologous donation/blood conservation;
• Postpone ... elective surgery;
• Vaccine;
• Importation;
• Partial Implementation;
  • Control testing;
  • Targeted implementation in high risk areas.

Source Control

• Surveillance programs;
• Mosquito abatement - targeting of "risk areas"?
• Personal protection;
  • Free DEET for donors;
  • Advocate use of mosquito nets;
  • Media/Education on personal protection;
    • more aggressive;
    • targeted to potential donors.

Surveillance

• Improvements;
• Increased/more rapid reporting to enable identification of:
  • risk individuals;
  • high risk areas - contribute to targeting of control activities.

Screening Questions

• Additional specific/related:
  • Insect Bites;
  • Rash;
    
    
• Insect bite in last 10-12 days - may protect selves;
• Number of patients not report bites;
• Id. definite period e.g. one month;
• What is educational material now?
  • It is improvable?
• Plasma side;
  • Use of solvent/detergent treated plasma;
• Increase informed consent for recipient;
  • More information for WNV;
  • Ethical/Legal;
• Autologous donation;
• Postpone elective surgery;
• Education specific to WNV;
• Donor education - post donation;
• Surveillance of sentinal and human disease;
  • Then restricting blood collection;
• Is there a cut off point? Number infected vs hospitalized;
• Not clear why Manitoba has number infected horses and no human cases;
• If no human cases, what is the risk of donation?
• Caribou - North;
• Probable and confirmed to report on suspect as well;
  • Needs work on definitions;
  • Radio suspect vs confirmed;
• Rapid turn around on diagnostic testing;
• Stockpile;
  • Develop guidelines around use - re: immune compromised;
• Testing of stockpile in "Down time";
• Diversion of plasma to fractionation;
• WNV free area higher collection;
• Good surveillance systems - more research;
• Operators follow-up with donors 4-5 days after donation;
  • Book next donation same time;
• Use of pathogen reduction inactivation system;
• R/B of inactivation different for the product itself - should be done soon;
• Public screening of possible cases;
  • High endemic area;
• No addressing risk of clinical procedures/medical;
  • Especially in peak time;
  • Dispose reusable material;
• Rapid and single diagnostic test;
• Rapid patient screening;
• Integrated system;
  • Needs improvement;
• Spraying - Baiting for mosquitoes;
• Personal protection measures;
  • Message to regular donors;
• Free DEET for donors;
  • Better use of media;
• Ontario Public Health and CBS collaboration - best practice;
  • Use in other province;
• Centralized lab for large pool testing;
• Partial testing - Id. those more at risk;
• In USA - NAT does contract testing;
• Impact on changing questionnaire 3 vs 5 days;
• "Imported" cases;
  • If donate high (up arrow) hazard;
  • Screen for;
• Hot line - to report after donation;
• Alternatives to transfusion;
  • Blood conservation;
• Pedigree donors;
  • Increased surveillance
  • How goes through the population;
• Broader Issue - Eradication of problem vs testing;
  • Where allocate resources;
• Informed consent for recipients;
  • more uniform application;
  • may postpone elective procedure;
• Develop method to Id. those who are immune;
  • Promote donation;
• Good communication strategy;
  • Where at?
  • Be honest;
• Inform transfusion practioners;
• Vaccine development;
• Use of Artificial blood substitutes
• Import blood products;
• Sterilization procedures;
• Restrict use during season - guidelines re appropriate use;
• Drastic mosquito control of one year gives chance to develop test for next year;
• Aggressive use of pesticide;
  • Issues with public;
• Personal protection;
• Dragonfly breeding;
• Communication/education;
• Major media campaign

Purple Breakout Group: Question #5 - What areas of WNV research need focused attention?

Contact : CERB/CBE

Epidemiology

• Why Canada and USA transfusion infection associated?
• The real asymptomatic period;
• Natural history of disease;
• Length of immunity;
• Surveillance measures;
• Bird population - High Low and immunity over time;
• Infection in Children;
• Length of in effectivity - Ing studies;
• Surveys of high transfuse population;
• Rate of infection - the 80% - 20% split;
• Does immune = safe blood;
• Human population risk factors.

Biology of Virus

• Strains of;
  • How many?
  • What creates?
  • Immunity to;
• Apply existing knowledge and resources on I.V.;
• Viability of virus during storage;
• Infectivity - long term studies.
• Viral replication - understand kinetics of;
• Better animal models;
• Virulence of different strains - How? Why?
• Stability of Viral particles.

Testing/Technology

• Sensitivity and specificity;
• Multivalent probes;
• Screening of plasma;
• Life in storage;
• Multiplexing;
• Platforming vs copies - relationship;
• Rapid test.

Public Health

• Effectiveness of mosquito control
• Vaccine development;
• Cost analysis of WNV prevention;
• Public perception and impact on blood donation and acceptance.

Product Safety

• Impact of inactivation products.

Parking Lot

• Do we really need focused research on WNV?
• Only for blood?
  • Organs?
  • Tissues?

Biography of Dr. A. Klein (Chair)

Contact : CERB/CBE

Dr. Agnes V. Klein is currently Acting Director, Biologics and Radiopharmaceuticals Evaluation Centre, Biologics and Genetic Therapies Directorate.

Dr. Klein received her medical degree from the University of Toronto. She trained in Endocrinology, Medical Biochemistry and Public/Community Health. Dr. Klein joined Health Canada and the Drugs Directorate in 1974 and has occupied many and varied scientific and management positions within Health Canada and its regulatory arms. Amongst these is having acted as the Director of the Bureau of Human Prescription Drugs. Since April, 2000, Dr. Klein has been with the Biologics and Genetic Therapies Directorate, initially as a Senior Medical Advisor and most recently as the Manager of the Clinical Evaluation Division, responsible for pre-market review as well as for decisions in respect of post-market events relating to biological/biotechnology agents.

Dr. Klein is an active member of several medical and scientific organizations nationally and internationally. She is also a recent member of the DIA's Canadian Programme Steering Committee. Dr. Klein's special interests include the appropriate design of clinical trials and the ethical issues attendant to them. Dr. Klein is a member of Health Canada's Research Ethics Board.

Workshop Summary Report

Contact : CERB/CBE

Executive Summary:

• There is current evidence that West Nile Virus (WNV) can be transmitted via blood transfusion or transplantation but, to date, no test is available to screen blood donations.
• An International Regulatory Consultative Workshop on the issue of WNV was organized and sponsored by Health Canada on January 9, 2003. The meeting involved over 120 delegates from federal, provincial, territorial ministries, members of the public, test kit manufacturers, industry, health care professionals as well as internationally recognized scientists working on WNV.
• Key International speakers reviewed the State of the Art Knowledge in this area and Health Canada presented current options for managing WNV risk and solicited feedback from stakeholders on approaches to address risk.
• Stakeholders lauded Health Canada actions to date and re-enforced the following actions:
  1. spurring commercial WNV test development (targeted for July 1, 2003) as highest priority;
  2. working with Health Canada to move research tests currently developed to blood operating environment as a contingency if no donor screening test is available;
  3. developing contingencies such as stockpiling of "out of season" collected blood components;
  4. working up geographic risk assessments to allow collecting blood from non-endemic areas during the mosquito season;
  5. researching a limited donor testing capability for high risk patients;
  6. adopting more rigorous pre and post donation screening and;
  7. working with all stakeholders to consider options to limit exposure of the population at risk of WNV infection.
• Canada is already moving forward with many of these contingencies. For example, both CBS and Héma Québec have already begun to stockpile frozen blood components and have met with Health Canada to develop selective testing strategies as well as to discuss use of a research test for WNV in case a commercial test is delayed.

Health Canada's West Nile Virus (WNV) International Regulatory Consultative Workshop held in January, 2003 in Ottawa

In mid November, Health Canada' Health Products and Food Branch (HPFB) developed a broad agenda for an international meeting on WNV. A broad range of stakeholders was invited including representatives of provincial and territorial ministries of health, representatives from industry developing commercial WNV test kits, staff from Canadian Blood Services and Hema Quebec, the plasma fractionation industry, public interest groups, non governmental organizations with a focus on blood safety, stakeholders in transplantation, clinicians and scientists focused on WNV research and representatives from the United States government (Centers for Disease Control, Atlanta and Food and Drug Administration, Washington). HPFB's Office of Consumer and Public Involvement (OCAPI) played a key role in identifying key stakeholders and providing expert facilitation service to the meeting.

The purpose of the meeting was to share information and present Health Canada's options for managing WNV risk to a wide group of stakeholders and gather feedback on the appropriateness of proposed risk reduction measures. The meeting focused on the following key areas: managing WNV risk, WNV testing, WNV blood system operators perspectives and a series of facilitated breakout sessions addressing 5 key questions including:

1. What are the key messages to be communicated to the public about WNV risk?
2. What strategies should be considered to reduce the risk of WNV transmission through transfusion or transplantation with pros and cons being addressed for each strategy?
3. What processes can be put in place to facilitate development of testing for WNV?
4. What measures should be considered to reduce risk if tests for WNV are not available and finally,
5. What areas of WNV research need focused attention?

As to feedback received for the question of what are the key messages to be communicated to the public about WNV Risk, it was clear that stakeholders felt there is a need for the federal government to provide leadership with respect to communication of WNV risk to the public. Messaging to the public should be accurate and consistent, emphasizing that WNV risk can and should be managed in partnership with all stakeholders including blood system operators, F/P/T jurisdictions and the public. Risk of WNV is clearly less serious than HIV risk or hepatitis and there is a need to maintain confidence in the safety of the blood system. It was noted as "very important" to communicate that managing WNV risk is a moving target to some extent, and we must adapt messaging based on the most recent information available. Lastly, stakeholders recognized that it is not possible to have 100% safe blood and that the risk of not having blood available may be greater than blood potentially infected with WNV(perceived to be a much lower risk).

Generally, stakeholders were very comfortable with Health Canada's various strategies to reduce risk of WNV infection through transfusion or transplantation. Indeed all of the options discussed by Health Canada during the meeting were re-enforced by feedback through the facilitated sessions. These included:

1. Priority given to development and implementation of a WNV screening test;
2. Contingency planning to develop a test that could be used in case there is no bonafide blood test;
3. Increase blood donations in non-endemic areas;
4. Stockpiling of "winter-collected" blood components to be used during the mosquito season;
5. Improving pre-donation screening and post donation follow up measures (more active reporting of post donation symptoms potentially attributable to early WNV disease);
6. Reduction of general population risk through vector abatement measures (mosquito spraying) and personal protection (repellants);
7. Research on blood substitutes; and
8. Research/implementation of viral inactivation technologies for blood.

Given the priority for development of a WNV blood donor screening test, Health Canada canvassed stakeholders about what processes could be put in place to facilitate testing development. Several of the key responses were as follows:

1. Planning and co-ordination of efforts by all stakeholders absolutely necessary;
2. Allow fast track regulatory review of tests including consideration for phased in implementation and post implementation approval; and
3. Communicate aggressively and actively:
   1. with industry to provide regulatory guidance as to requirements and standards for test;
   2. with blood system operators to facilitate timely implementation; and
   3. with U.S. regulatory authorities to share information, harmonize requirements if possible. There was recognition that timelines are tight and there are concerns that adequate resourcing may not be in place both within the regulatory authorities and blood system operators for shortening implementation times. In the event that a blood donor test for WNV is not available, stakeholders lauded Health Canada's options presented during the plenary session of the meeting and offered the following additional options to consider in addition to options a) through h) above:
   4. Improve donation screening by considering an enhanced health assessment or questions with seasonal adjustment;
   5. Address general WNV risk reduction by educating donors about mosquito protection measures;
   6. emphasize/enhance autologous donation programs;
   7. increase efficiency of WNV surveillance; and
   8. define non-endemic areas and make use of the information to reduce risk.

Lastly, there was important information collected about what areas of WNV research need focused attention. Specifically, research should continue to be focused on understanding more about the biology and pathogenesis of WNV and how infection can be detected/prevented. Studies were recommended to address mechanism and length of immunity to WNV and continued research effort being applied to development of a vaccine (expected in 2004-2005).

As gleaned from the above, efforts to manage WNV risk is a high priority within Health Canada. Several new initiatives stemming from the successful WNV consultative regulatory workshop have already begun in order to prepare for the 2003 mosquito season. It is expected that industry will deliver on a WNV blood donor test by July, 2003. However, if this deadline is not met, the Department has considered and put in place a number of contingency plans as described in this summary in order to protect Canadians.