The Centers for Disease Control and Prevention says hospitals treating people for the flu should test them for avian influenza within 24 hours.

The U.S. Centers for Disease Control and Prevention on Thursday urged clinicians and laboratories to test for the variant of influenza A virus in patients ideally within 24 hours of hospitalization, as part of its efforts to tackle the ongoing sporadic human infections with bird flu.

The CDC has confirmed a positive bird flu case in a child in San Francisco, the second juvenile case of H5N1 in the country.

Public health officials have confirmed a San Francisco child is the second pediatric case of bird flu in the U.S. According to the CDC, no additional cases have been identified among the child's contacts.