Donor Suitability and Blood and Blood Product Safety in Cases of Known or Suspected West Nile Virus Infection Current Considerations

1
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

2
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

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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)

4
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

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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 _at_ 56 days with
  consideration of automatic re-entry at later time
  point

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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

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FDA Current Considerations 90 day Donor
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 _at_ 90 days

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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 gt56 days after
  diagnosis or onset of illness when donor has been
  tested and found negative by IDT WNV NAT

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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.

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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 gt56 days after
  diagnosis or onset of illness when donor has been
  tested and found negative by IDT WNV NAT

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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.

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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