When evidence emerged in 2002 that the West Nile virus could be transmitted through blood, the US Food and Drug Administration (FDA) and blood-screening organizations reacted quickly to maintain the safety of the blood supply by screening for this infectious agent. By 2003, the FDA had recommended that blood banks screen blood for the West Nile virus using an investigational nucleic acid test. Since then, blood banks across the country have used various strategies, including individual or pooled blood sample testing, to prevent this infectious agent from contaminating the blood supply.
Kuehn BM. Studies Propose Targeted Screening of Blood for West Nile Virus. JAMA. 2006;295(11):1235-1236. doi:10.1001/jama.295.11.1235