Archived: H5 Viruses in the United States

Highly pathogenic avian influenza (HPAI) H5 infections have been reported in U.S. domestic poultry (backyard and commercial flocks), captive wild birds, and wild birds by the U.S. Department of Agriculture (USDA) and the U.S. Department of Interior (DOI)*. HPAI H5 detections began in December 2014 and continued into mid-June 2015. During that time H5 bird flu virus detections were reported in 21 U.S. states (15 states with outbreaks in domestic poultry or captive birds and 6 states with H5 detections in wild birds only). It is possible that H5 outbreaks in birds in the United States may recur in the fall and winter. Surveillance for H5 in U.S. birds is ongoing.

The Centers for Disease Control and Prevention is the lead Federal agency for the human health response. At this time, no human infections with these viruses have been detected, however similar viruses have infected people in other countries and caused serious illness and death in some cases. Human infections with other avian influenza viruses have occurred after close and prolonged contact with infected birds or the excretions/secretions of infected birds (e.g., droppings, oral fluids).

While the health risk posed to the general public by domestic HPAI outbreaks is low, it is possible that human infections with these viruses could occur. CDC has guidance for clinicians and public health professionals in the United States on appropriate follow-up, preventive treatment, testing, specimen collection and processing of samples from patients who may be infected with H5 viruses.

* The U.S. Department of Interior (DOI) and the United States Department of Agriculture (USDA) are the lead federal agencies for outbreak investigation in wild birds and the USDA APHIS is the lead agency investigation and control activities in domestic birds.

Risk to Human Health
  • No human infections with U.S. H5 viruses have occurred
  • Similar viruses have infected humans in other countries
  • People in contact with known infected or possibly infected birds should take precautions to protect against infection
CDC Recommendations for the Public
  • As a general precaution, people should avoid wild birds and observe them only from a distance; avoid contact with domestic birds (poultry) that appear ill or have died; and avoid contact with surfaces that appear to be contaminated with feces from wild or domestic birds.
  • People who have had contact with infected bird(s) should monitor their own health for possible symptoms (for example, conjunctivitis, or flu-like symptoms).
  • People who have had contact with infected birds may also be given influenza antiviral drugs preventatively.
  • Health care providers evaluating patients with possible HPAI H5 infection should notify their local or state health departments which in turn should notify CDC. CDC is providing case-by-case guidance at this time.
  • There is no evidence that any human cases of avian influenza have ever been acquired by eating properly cooked poultry products.
  • CDC will update the public as new information becomes available.