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Donor Suitability and Blood and Blood Product Safety in Cases of Known or Suspected West Nile Virus Infection Current Considerations. Alan E. Williams, Ph.D. Director, Division of Blood Applications OBRR/CBER/FDA Blood Products Advisory Committee March 17, 2005. Previous FDA Recommendations.
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Donor Suitability and Blood and Blood Product Safety in Cases of Known or Suspected West Nile Virus InfectionCurrent Considerations Alan E. Williams, Ph.D. Director, Division of Blood Applications OBRR/CBER/FDA Blood Products Advisory Committee March 17, 2005
Previous FDA Recommendations Recommendations for the Assessment of Donor Suitability and Blood and Blood Product Safety in Cases of Known or Suspected West Nile Virus Infection • Final Guidance: October 25, 2002 • Revised May 1, 2003 • Deferral for WNV infection – 28 days from symptom onset or 14 days post-symptom resolution • Donor self-report of “fever with headache in past week” 28 day deferral
Observational data: Donor screening by WNV NAT and follow-up studies conducted under IND • Maximum observed WNV viremic period in blood donors to date is 49 days • 6.5 to 56.4 day range of WNV viremia includes 99% of WNV infected donor population according to one model • Infectivity of low level viremia co-existent with WNV IgM is unknown (No post-transfusion WNV cases observed to date from IgM+ donors)
Observational data: Donor screening by WNV NAT and follow-up studies conducted under IND (cont.) • Individual Donation Testing (IDT) NAT improves donor screening sensitivity but is not feasible year-round • Donor screening for WNV-related symptoms introduced prior to widespread WNV NAT screening is of questionable predictive value. • Geographic focus, timing and extent of 2005 WNV activity in US not known, but continued epizootic activity is likely in previously affected areas
BPAC Recommendations October 22, 2004 • Extend deferral period from 28 to 56 days (Encourage data collection to determine if 56 days is sufficient to rule-out viremia) • WNV IDT prior to re-entry @ 56 days with consideration of automatic re-entry at later time point
BPAC Recommendations October 22, 2004 • Discontinuation of previously recommended “fever with headache in past week” question with encouragement of better case-control data to determine if any of symptom cluster may be more predictive of early WNV infection
FDA Current Considerations: 90 dayDonor Deferral • Donors with diagnosed or suspected acute WNV illness or infection • Donors with suspected post-donation WNV illness- • Donors who may have transmitted WNV infection • Re-entry possible after 56 days based upon negative IDT NAT on sample (or donation sample) • Re-entry without additional testing @ 90 days
FDA Current Considerations: Product Management Diagnosed WNV Infection or Illness in a Donor • Retrieval and quarantine of in-date products 14 days prior to onset of illness and 90 days after diagnosis or onset of illness (whichever is later) • Exception for products collected >56 days after diagnosis or onset of illness when donor has been tested and found negative by IDT WNV NAT
FDA Current Considerations: Product Management Donors who are potentially associated with transfusion-transmitted WNV infection - (defined as donors of “suspect” donations received by a recipient up to 56 days prior to recipient WNV infection) • Retrieval and quarantine of other donations by potentially associated donors 56 days before and 56 days after the suspect donation.
FDA Current Considerations: Product Management Undiagnosed Post-Donation Illness in Potentially Exposed Individuals • Medical Director judgement regarding product quarantine and retrieval considering dates of WNV transmission potential (May 1 to November 30) • When conducted, quarantine and retrieval of in-date products 14 days prior to, and 90 days after onset of donor symptoms • Exception for products collected >56 days after diagnosis or onset of illness when donor has been tested and found negative by IDT WNV NAT
FDA Current Considerations: Product Management • Product retrieval and quarantine not recommended for Source Plasma, Recovered Plasma, or Source Leukocytes that have been pooled for fractionation.
FDA Current Considerations: Notification of Prior Transfusion Recipients about possible WNV exposure Relevant units are those collected 14 days prior through 56 days after the onset of diagnosed WNV illness in a donor - or - Units collected from a donor 56 days prior to 56 days after a donation from that donor is identified as the likely source of a WNV transfusion transmission. • Establishments should consider tracing records and notifying transfusion services of relevant units