In the article, "Update: Detection of West Nile Virus in Blood Donations
United States, 2003," an error occurred on page 918 in the second sentence
of the third full paragraph discussing Case 2. The sentence should read, "These
20 samples were tested by NAT at three different laboratories; one sample
tested equivocal at one laboratory (Lab A), reactive in a second, and nonreactive
in a third." This sample subsequently tested positive for West Nile virus
RNA at a fourth laboratory and was reactive when retested at Lab A by using
a larger extraction volume (estimated virus titer: 0.1 plaque-forming units/mL).