Officials: Blood test for West Nile virus won't be easy to develop

WASHINGTON (AP) -- Officials don't yet know if a blood test for West Nile virus is even needed -- but if it is, it won't be easy to develop.

Health officials were scrambling to determine if West Nile virus can be spread through blood transfusions, even as they emphasized that the blood supply is very safe. The risk of contracting West Nile from blood is significantly lower than the risk of forgoing any procedure that would call for a blood transfusion, they said.

Ultimately, a screening test is probably needed, said Dr. Lester Crawford, acting commissioner of the Food and Drug Administration. He said government would work with industry to stimulate faster development of a test.

Even so, testing for the virus is complicated.