The Centers for Disease Control issued a health alert calling for the immediate testing of patients hospitalized with influenza A to quickly identify avian flu cases.
The CDC's new guidance comes after a child tested positive for the virus in San Francisco who had no known contact with animals. Nirav Shah, principal deputy director for the CDC, said there is still no evidence of human-to-human transmission of the bird flu. He added that the overall risk to the public is low.
"At this time, no clear exposure source has been identified, including to any animals, but the investigation remains underway," Shah said.
Officials said that the child has recovered.
“CDC is continuing to work closely with health officials in San Francisco, specifically on serology or antibody studies among those household members to look to see whether they have any evidence of prior infection," Shah said, adding that no one else in the family had symptoms of the virus.
Most influenza tests do not distinguish avian influenza viruses from seasonal influenza A viruses, the CDC said.
To date, there have been 67 U.S. cases of avian flu. There was one reported fatality tied to avian flu in Louisiana earlier this year.
Health officials revealed that the patient who died was hospitalized in mid-December after being exposed to "non-commercial backyard flock and wild birds."
Most U.S. cases have resulted in mild symptoms for patients in the U.S. and a full recovery. However, past cases of bird flu in humans in other countries have been severe, with some resulting in death, according to federal health officials.
Prevention measures include avoiding contact with sick or dead animals, in particular wild birds, and poultry.
RELATED STORY | Pet food recalled after testing positive for bird flu
U.S. Department of Agriculture officials added that they are expanding its national milk testing strategy, starting with states where bird flu has been found in infected herds.
