Variant Creutzfeldt-Jakob disease deferral in Canada: impact of stop dates.
To reduce the risk of variant Creutzfeldt-Jakob disease (vCJD) transmission via blood transfusion in Canada, potential donors who spent a cumulative time in the United Kingdom, Western Europe or Saudi Arabia are deferred. "Stop dates" for accumulated time were later implemented for 3 months spent in the United Kingdom or France (1980-1996) and for 5 years elsewhere in Western Europe (1980-2007); Saudi Arabia deferral was implemented with the "stop date" (1980-1996). We evaluated the long-term impact of these deferrals and "stop dates", as well as the consistency of donors' answers to post-implementation screening questions.



The monthly deferral rate was monitored from 2003-2015. Time series methods (ARIMA) were used with interruption when "stop dates" were implemented. A telephone survey of 1,000 donors (250 first-time, 500 repeat deferred donors, 250 non-deferred control donors) assessed travel history (response rate 62%). An anonymous mail survey of 40,000 donors assessed compliance with deferral (response rate 45.3%).



When the "stop date" for UK/France travel was implemented, the deferral rate decreased for first-time (2.1% to 1.1%, p<0.0001) and repeat (0.2% to 0.03%, p<0.0001) donors. The deferral rate increased after Saudi Arabia was included (mean increase of 0.4% first-time, 0.02% repeat, p<0.0001). After the Western Europe "stop date" the deferral rate was unchanged in first-time donors (1.0% to 1.1%, p=0.5) but decreased in repeat donors (0.03% to 0.02%, p<0.002). In the telephone survey, 94% of deferred donors confirmed deferrable travel history. In the anonymous survey 0.3% of donors were non-compliant with the UK/France deferral.



Donors, particularly first-time ones, continue to be lost due to vCJD travel deferral, but most deferrals are correctly applied and non-compliance is rare. The application of a "stop date" reduced deferrals for UK/France travel, but it may be too early to see the full impact of the "stop date" for Western Europe.
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.|School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada.
Sheila F
SF
O'brien
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.
Wenli
W
Fan
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.|School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, ON, Canada.
Qi-Long
QL
Yi
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.
Samra
S
Uzicanin
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.
Lori
L
Osmond
Canadian Blood Services, University of Ottawa, Ottawa, ON, Canada.|Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, ON, Canada.
Mindy
M
Goldman
D000328:Adult; D002170:Canada; D007562:Creutzfeldt-Jakob Syndrome; D046148:Donor Selection / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014195:Travel