FDA OKs Blood Test for West Nile

Chiron Corp. and Gen-Probe Inc. have won the first U.S. approval of a test to screen donated blood for the deadly West Nile virus typically transmitted to humans by mosquito bites.

Blood banks in the United States have been using experimental tests, including Chiron and Gen-Probe’s Procleix, to screen for the virus, the Food and Drug Administration said Thursday in a statement.

The tests have identified the virus in about 1,600 donations, which were then destroyed, the FDA said. Switzerland’s Roche Holding also has an experimental test for West Nile.

The agency has reports of 30 people who probably acquired West Nile virus from blood donations, including nine who died. The virus was first detected in the U.S. in 1999, and 762 people have died of the disease since 2002, the FDA said. Scientists also discovered that year that blood donations could carry the West Nile virus, the FDA said.

Shares of Emeryville, Calif.-based Chiron rose 1 cent to $44.31. Shares of San Diego-based Gen-Probe rose $3.01 to $49.18.

The Procleix test screens more than 80% of the blood supply in U.S. centers, Gen-Probe said.