CDC considers the risk to people
from these HPAI H5 infections in wild birds, backyard flocks and commercial
poultry, to be low.
WASHINGTON, April 14, 2015 -- The
United States Department of Agriculture’s (USDA) Animal and Plant Health
Inspection Service (APHIS) has confirmed the presence of highly pathogenic H5N2
avian influenza (HPAI) in a commercial turkey flock in Buena Vista County,
Iowa. The flock of 27,000 turkeys is located within the Mississippi flyway
where this strain of avian influenza has previously been identified. CDC
considers the risk to people from these HPAI H5 infections in wild birds,
backyard flocks and commercial poultry, to be low. No human infections with the
virus have been detected at this time.
Samples from the turkey flock, which experienced
increased mortality, were tested at the Iowa State University Veterinary
Diagnostic Laboratory and the APHIS National Veterinary Services Laboratories in
Ames, Iowa confirmed the findings. NVSL is the only internationally recognized
AI reference laboratory in the U.S. APHIS is working closely with the Iowa
Department of Agriculture and Land Stewardship on a joint incident response.
State officials quarantined the premises and birds on the property will be
depopulated to prevent the spread of the disease. Birds from the flock will not
enter the food system.
The United States has the strongest AI surveillance
program in the world. As part of the existing USDA avian influenza response
plans, Federal and State partners as well as industry are responding quickly and
decisively to these outbreaks by following these five basic steps: 1) Quarantine
– restricting movement of poultry and poultry-moving equipment into and out of
the control area; 2) Eradicate – humanely euthanizing the affected flock(s); 3)
Monitor region – testing wild and domestic birds in a broad area around the
quarantine area; 4) Disinfect – kills the virus in the affected flock
locations; and 5) Test – confirming that the poultry farm is AI virus-free.
USDA also is working with its partners to actively look and test for the disease
in commercial poultry operations, live bird markets and in migratory wild bird
The Iowa Department of Health is working directly
with poultry workers at the affected facility to ensure that they are taking the
proper precautions. As a reminder, the proper handling and cooking of poultry
and eggs to an internal temperature of 165 ˚F kills bacteria and viruses.
USDA will include the confirmation information in
routine updates to the World Organization for Animal Health (OIE), and will
notify international trading partners of this finding as appropriate. OIE trade
guidelines call on countries to base trade restrictions on sound science and,
whenever possible, limit restrictions to those animals and animal products
within a defined region that pose a risk of spreading disease of concern.
These virus strains can travel in wild birds
without them appearing sick. People should avoid contact with sick/dead poultry
or wildlife. If contact occurs, wash your hands with soap and water and change
clothing before having any contact with healthy domestic poultry and birds.
All bird owners, whether commercial producers or
backyard enthusiasts, should continue to practice good biosecurity, prevent
contact between their birds and wild birds, and report sick birds or unusual
bird deaths to State/Federal officials, either through their state veterinarian
or through USDA’s toll-free number at 1-866-536-7593. Additional information on
biosecurity for backyard flocks can be found at http://healthybirds.aphis.usda.gov.
Avian influenza (AI) is caused by an influenza type
A virus which can infect poultry (such as chickens, turkeys, pheasants, quail,
domestic ducks, geese and guinea fowl) and is carried by free flying waterfowl
such as ducks, geese and shorebirds. AI viruses are classified by a combination
of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16
(H1–H16), and neuraminidase or “N” proteins, of which there are 9 (N1–N9). Many
different combinations of “H” and “N” proteins are possible. Each combination is
considered a different subtype, and can be further broken down into different
strains. AI viruses are further classified by their pathogenicity (low or high)—
the ability of a particular virus strain to produce disease in domestic
The HPAI H5N8 virus originated in Asia and spread
rapidly along wild bird migratory pathways during 2014, including the Pacific
flyway. In the Pacific flyway, the HPAI H5N8 virus has mixed with North American
avian influenza viruses, creating new mixed-origin viruses. These mixed-origin
viruses contain the Asian-origin H5 part of the virus, which is highly
pathogenic to poultry. The N parts of these viruses came from North American low
pathogenic avian influenza viruses.
USDA has identified two mixed-origin viruses in the
Pacific Flyway: the HPAI H5N2 virus and new HPAI H5N1 virus. The
new HPAI H5N1 virus is not the same virus as the HPAI H5N1 virus
found in Asia, Europe and Africa that has caused some human illness. Only the
HPAI H5N2 virus has been detected in the Pacific, Mississippi and Central
Detailed analysis of the virus is underway in
cooperation with the U.S. Centers for Disease Control and Prevention. For more
information about the ongoing avian influenza disease incidents visit the APHIS
website. More information about avian influenza can be found on the USDA
avian influenza page. More information about avian influenza and public
health is available on the CDC