If Zika virus comes to the United States, will the US blood supply be at risk?

Because the disease has demonstrated that it can pass via blood from mother to fetus, and via other bodily fluids between sexual partners, the question lurks in the back of most discussions of Zika’s likely arrival on the US mainland. And because there is not now a test for donated blood, keeping the virus out of the blood supply relies on people adhering to restrictions published by the Food and Drug Administration that ask travelers to defer donating for a period of time—an imprecise deterrent, but currently as good as it gets.

The concern for the blood supply is reasonable. In 2002, when West Nile virus