The government has approved a new genetic test for the flu virus that will allow labs across the country to identify flu strains within a few hours.

Federal health officials say the timesaving test could be crucial if a deadly new strain emerges. Tests today take three to four days for results. The new test also could help doctors make better treatment decisions during a conventional flu season.

The Food and Drug Administration approved the test Tuesday. Government health laboratories are expected to start using the test this fall. The test was developed by another federal agency, the Centers for Disease Control and Prevention.