A whole blood donor's sample was reactive with initial testing using the anti-HIV 1/2 EIA screen. Repeat testing was performed in duplicate. One of the repeat tests was reactive.

1. What is the final interpretation of this donor's anti-HIV 1/2 test?
2. Is further testing required on this donor? Explain.
3. Which regulatory agency requires further testing?
4. If both repeat screening tests were nonreactive, what is the final interpretation of the result?
5. Can HIV be missed with screening testing? Explain.