Health officials in Marin County, California, are now investigating a possible case of the H5N1 bird flu in a child.
The health officials are currently working with the Centers for Disease Control and Prevention (CDC) and the California Department of Public Health to determine the possible source of the infection.
The possible infection was reported in a Friday "health status update" newsletter published on the Marin Health and Human Services website. If confirmed, it would be the second time that a child in California has been infected by the H5N1 avian flu.
Bird Flu in Humans in the United States
As of Dec. 8, the CDC has confirmed 58 reports of human cases of bird flu in the country. Included in those cases is a child in Alameda County who tested positive for the disease last month. Much like this new case, health officials have not been able to determine the source of the exposure.
It can also be noted that the child had developed mild respiratory symptoms. However, no one else in the child's family or daycare was infected by the disease.
Furthermore, the new case will be the third in the country this year where the source of exposure is unknown. Aside from the case in Alameda, health officials in Missouri also reported the state's first human case of H5N1 in September.
That infection was detected through the state's ongoing influenza surveillance program. The patient, whose identity was not publicly released, was hospitalized on Aug. 22 with underlying medical conditions and a positive test for influenza A. Notably, the patient did not report any exposure to animals.
Why Is the Rise in Human Bird Flu Cases a Concern?
Experts first voiced concerns about potential human-to-human transmission of the bird flu virus when one household member and six healthcare workers who had contact with the Missouri patient developed symptoms.
All possible contacts underwent testing. The six healthcare workers tested negative for bird flu, but that one household member who showed symptoms simultaneously with the initial patient also tested positive for H5N1.
Still, the CDC said they have not seen any evidence of sustained human-to-human transmission.
