The Centers for Disease Control and Prevention (CDC) has issued a health advisory regarding the possibility of highly-pathogenic avian influenza (HPAI) H5 virus infection in humans after more than 200 infections in birds have been reported since December 2014.

The U.S. Department of Agriculture (USDA) has confirmed more than 200 findings of birds infected with HPA1 A (H5N2), (H5N8), and (H5N1) viruses between December 15, 2014 and May 29, 2015. These are the first reported infections with these viruses in U.S. wild or domestic birds and the majority of the infections have occurred in poultry. The appearance of these recently-identified HPAI H5 viruses may increase the risk of human infection in the United States, although the viruses are not known to have caused disease in humans. The CDC considers the risk to be low, but those with close or prolonged unprotected contact with infected birds or contaminated environments may be at an increased risk of infection.

It is recommended that clinicians consider HPAI H5 virus infection in persons showing signs or symptoms of respiratory illness who have relevant exposure history, including those who have had contact with potentially-infected birds (eg, handling, slaughtering, defeathering, butchering, culling, preparation for consumption); direct contact with surfaces contaminated with feces or parts (carcasses, internal organs, etc.) of potentially infected birds; and prolonged exposure to potentially infected birds in a confined space. Those who meet clinical and exposure criteria should be tested for HPAI H5 virus infection by reverse-transcription polymerase chain reaction (RT-PCR) assay with H5-specific primers and probes.