# Presentation: 665939

## 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

**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 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 @ 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