The U.S. Centers for Disease Control and Prevention is urging health care workers to accelerate bird flu testing for patients hospitalized with flu symptoms.

A child ill with fever and conjunctivitis in San Francisco tested positive for bird flu but had no known source of transmission.

People hospitalized for flu should be tested for bird flu within 24 hours, the U.S. Centers for Disease Control and Prevention said on Thursday, in an expansion of the agency's efforts to tackle increasing infections in humans.