An understanding of characteristics of blood donors donating in times
of crisis may help predict blood supply safety and donor return patterns.
To characterize the volume of donations and prevalence of infectious
disease markers in blood donated by US donors responding to the September
11, 2001, terrorist attacks, and to evaluate return rates in those who donated
for the first time.
Cross-sectional survey data from the National Heart, Lung, and Blood
Institute Retrovirus Epidemiology Donor Study for 4 weeks before and 4 weeks
starting with September 11, 2001, and the corresponding 8-week period in 2000.
Setting and Participants
A total of 327 065 volunteer blood donors making 373 628 allogeneic
donations at 5 large regional US blood centers.
Main Outcome Measures
Changes in number of donations overall and by first-time and repeat
status, prevalence of infectious disease markers, estimated risks of transfusion-transmitted
viral infections, and first-time donor return rates.
About 20 000 allogeneic donations were collected weekly in the
4 weeks preceding September 11, whereas ≈49 000 (2.5-fold increase)
and ≈26 000 to 28 000 (1.3-fold to 1.4-fold increases) donations
were made per week in the first and in the second through fourth weeks starting
with September 11, respectively. All demographic groups donated more than
usual after the attacks, and after adjusting for seasonal and annual variation
there was a 5.2-fold (95% confidence interval, 5.0-5.4) increase in the number
of first-time donations vs a 1.5-fold (1.4-1.5) increase in the number of
repeat donations made in the first week starting on September 11 vs the 4
weeks before. The weekly proportion of repeat donors returning after not donating
for 10 or more years increased from 2% before September 11 to 6% in the first
week starting with September 11. Donations confirmed positive for human immunodeficiency
virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen nearly
tripled between 1 week before September 11 (0.1%) and 1 week after the attacks
(0.3%), largely explained by the increase in first-time and lapsed repeat
donors. Estimated viral residual risks increased slightly after the attacks
(HIV, 1/1.5 million vs 1/1.8 million donations; HCV, 1/1.3 million vs 1/1.6
million; hepatitis B virus, 1/140 000 vs 1/170 000). First-time
donor 12-month return rates for 2000 and 2001 were similar, ≈28% (P = .37) for donors in the first week starting with September
11 (or September 12, 2000) and 30% (P = .69) for
the second to fourth weeks.
The September 11 events resulted in an influx of first-time donors without
substantial increase in absolute risk of transfusion-transmissible viral infections.
First-time donor return rates were equally relatively low before and after
the attacks, suggesting that those donating in times of crisis have return
behaviors similar to those of other first-time donors. Their relatively low
return rates reinforce the need for education about the importance of donating