UPDATE: Outbreaks of Avian Influenza A H5 in U.S. Wild and Domestic Birds - HHS Expands Guidance on the Use of Influenza Antiviral Drugs

May 26, 2015 - Since December 2014, newly identified highly pathogenic avian influenza (HPAI) H5 viruses have been detected among domestic poultry (backyard and commercial flocks), captive wild birds, and wild birds in the United States. These outbreaks have continued since that time and as of May 20, 2015, 20 states have reported outbreaks of HPAI H5 viruses.

While no human infections with these H5 viruses have been reported to date, there is concern that these viruses could cause illness in humans, as genetically similar H5 influenza viruses (e.g., H5N1 virus in Asia and other parts of the world) have caused severe illness in the past among people, most of whom had prolonged and close contact with infected birds. CDC’s public health efforts are geared to decreasing the risk of human infection with these newly identified H5 viruses.

CDC considers the risk to the general public from these HPAI H5 viruses to be low, but not zero, and that these HPAI H5 viruses have the potential to cause severe disease in humans. People with close or prolonged, unprotected contact with infected birds or contaminated environments—including owners or caretakers of birds and persons engaged in implementing control measures, such as those culling affected flocks—may be at greater risk of infection.

Appropriate use of influenza antiviral drugs is a key component of response-and-control measures for this outbreak and may help reduce the risk of human cases and subsequent person-to-person spread. CDC has provided guidance on the use of influenza antiviral drugs in the current situation, which includes recommendations for 1) prompt treatment of persons with possible HPAI H5 virus infection, 2) early post-exposure prophylaxis of their asymptomatic close contacts based on risk of exposure, and 3) consideration (based on clinical judgment) of prophylaxis of persons exposed to infected birds. Guidance documents are available on the CDC website at Avian Influenza: Information for Health Professionals and Laboratorians.  Individuals exposed to HPAI H5 viruses who are being considered for prophylaxis or for empiric treatment of possible infection with HPAI H5 virus infection must have access to a prescription and the appropriate drug. To help decrease the risk of human infection with these HPAI strains and the possibility of subsequent person-to-person spread, state and local public health officials are encouraged to help facilitate access to these drugs as part of this strategy. This may be through the normal healthcare system or by providing select products from public health antiviral drug stockpiles.

To assist in this effort, state health departments should be aware that the U.S. Department of Health and Human Services (HHS) has amended its guidance on the use of antiviral drugs that have been stockpiled for use during an influenza pandemic. HHS continues to recommend that state stockpiles of antiviral drugs be reserved for pandemic use, but has expanded its recommendation to allow use of some select state and federal product to support current domestic HPAI H5 response efforts. This product should not be used to treat seasonal influenza cases.

For more information on which public health stockpiles may be used to help prevent and control potential human infections with HPAI H5, please contact CDC at dsns-request@cdc.gov.

For more information about influenza antiviral drugs and avian influenza, visit the CDC avian flu web site or call (800)-CDC-INFO [(800) 232-4636]. Also visit USDA’s Department of Agriculture Research Service (ARS) and Animal and Plant Health Inspection Service (APHIS) websites.