Abstract | BACKGROUND: To decrease the likelihood of transmission from donations containing West Nile virus (WNV) levels below minipool nucleic acid test (MP- NAT) detection limits, blood centers switch from MP- NAT to individual-donation testing (ID- NAT) after detection of MP- NAT-positive donations. The effectiveness of strategies to trigger or discontinue ID- NAT screening is largely unknown. STUDY DESIGN AND METHODS: Twenty-seven strategies to trigger and discontinue ID- NAT screening were evaluated with a statistical model based on known dynamics of WNV infection and historical data on WNV prevalence among blood donations. Breakthroughs were defined as WNV immunoglobulin M antibody-negative, viremic ( RNA-positive) donations that could only be identified by ID- NAT, but were screened by MP- NAT. Effectiveness (proportional reduction of breakthroughs relative to MP- NAT screening alone) and efficiency (absolute reduction of breakthroughs relative to the number of tests performed) were estimated by simulating donation years of varying outbreak severities over a range of blood collection frequencies. RESULTS: Most strategies were effective (>75% reduction in breakthroughs) when daily donations exceeded 560. In larger centers (1008 donations daily), effectiveness of trigger-on strategies based on absolute number of MP- NAT-positive donations improved, but worsened for strategies using rate-based criteria. Effectiveness increased slightly by triggering on one MP- NAT-positive rather than two and increased substantially by increasing the duration from 7 to 14 days that no ID- NAT-positive donations are detected before resuming MP- NAT. CONCLUSION: Most trigger strategies become effective when test results from at least 560 donations daily are considered. A 14-day ID- NAT period may improve safety relative to the increase in the number of tests performed.
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Authors | Brad J Biggerstaff, Lyle R Petersen |
Journal | Transfusion
(Transfusion)
Vol. 49
Issue 6
Pg. 1151-9
(Jun 2009)
ISSN: 1537-2995 [Electronic] United States |
PMID | 19309472
(Publication Type: Comparative Study, Journal Article)
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Chemical References |
- Antibodies, Viral
- RNA, Viral
|
Topics |
- Antibodies, Viral
(blood)
- Blood Donors
- Humans
- RNA, Viral
(blood)
- West Nile virus
(genetics, immunology, isolation & purification)
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