Several e-network colleagues have asked if there is a potential for spread of the infection via the blood supply now that the West Nile Virus appears to be increasing in the US. One colleague in particular reports that she is starting to get questions regarding eligibility of blood donors who have had or may have been exposed to West Nile Virus.

Currently, the inquiring physician presumes that she should defer prospective donors for symptoms, as always. However, she wonders if anyone knows a reasonable deferral period for a prospective donor who has actually had the disease? Any comments from those in areas where it has been present for some time would be welcome. For more details about West Nile Virus see the links to updated information in the Emerging Infectious Diseases section of our website, including the CDC's VBID page on this virus.

In response to the above, the following replies were received.

1. A blood banker from Rockville, Maryland wrote that it was his understanding that scientists affiliated with the CDC are preparing a manuscript on the transfusion risk of West Nile Virus. According to the responding blood banker, to date it appears that the viremic period is relatively short, one to two weeks before symptoms. The responding blood banker would hesitiate to suggest a deferral period. However, if there is any guidance for (say) St. Louis encephalitis, he would imagine that would be the model.

2. Editor's note:  Here is the link to the literature citation containing the CDC statement mentioned above, now available in the August 2002 issue of Transfusion.

Please submit comments to the e-Network Forum.

Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator