From Slate:

Policy: We ask you if you've had sex with a man since 1977. If you say yes, you can't donate. Rationale: You're an HIV risk. Objections: 1) Tests have improved, so we can detect HIV within three weeks of infection. 2) Therefore, the "have you ever" question should be modified from 30 years to three weeks, or at most, a year. FDA's rebuttal: The tests aren't perfect. Critics' rebuttal: Neither is the blood supply. Human Nature's view: The policy is nuts, since the tests are more reliable than the answers to the "have you ever" question.

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