Avian Influenza

University Awarded $22.5 Million to Study Avian Inflenza, click here to read more information about the grant.

Avian Influenza Frequently Asked Questions
GENERAL INFORMATION
ASIAN H5N1 AVIAN INFLUENZA
ASIAN H5N1 AVIAN INFLUENZA IN PEOPLE
INTERVENTION STRATEGIES

General Information

What is avian influenza?

•    Avian influenza is a disease of birds.

•    It is caused by a virus which is a small particle that can infect living things.

•    Viruses are much smaller than bacteria. They can only be seen with an electron microscope.

•    Viruses can multiply only inside the cells of living organisms, called host cells.

How are influenza viruses characterized?

•    Influenza viruses have external projections called Hemagglutinin (H) and Neuraminidase (N). There are 16 known Hs and 9 known Ns.

•    There are 144 subtypes of influenza virus based on their Hs and Ns; for example, H4N8 or H1N1.

•    The subtypes could be viewed as similar to 16 hair colors and 9 eye colors in humans.

•    Two pathotypes of virus are recognized: highly pathogenic viruses and mildly pathogenic viruses. Most isolates are mildly pathogenic.  Pathotype refers to ability to cause disease in chickens.

•    Highly pathogenic influenza viruses have only been found in the H5 and H7 subtypes. This does not mean that all H5s and H7s are highly pathogenic – most H5s and H7s are mildly pathogenic.

 Where does avian influenza come from? How is it introduced into a poultry flock?

•    Avian influenza virus is maintained in a worldwide natural reservoir of wild waterfowl and shorebirds as well as in a manmade reservoir in live poultry markets.

•    Sometimes the virus infects commercial poultry.

•    The virus was first reported in North America in the 1960s although it is now known that a different form of highly pathogenic influenza affected U.S. poultry in 1924-25 and 1929.

What animals can get avian influenza?

•    Usually only birds can get avian influenza.  A recent type of influenza, highly pathogenic H5N1 (bad bird flu) has not only infected many bird species but also cats, tigers and even people in Europe and Asia.  The cats and tigers were infected after eating raw infected chickens, whereas the humans were infected after having intimate contact with infected chickens or their manure.

Can dogs get avian influenza?

•    There is no evidence that dogs can get avian influenza.

How serious is avian influenza virus in poultry?

•    Highly pathogenic influenza virus results in high mortality in poultry flocks, and the detection of highly pathogenic influenza virus causes an emergency response that usually includes killing and disposal of infected chickens and implementation quarantines until the disease agent has been eliminated.

•    Mildly pathogenic influenza virus results in a milder disease although there may be severe illness  under some conditions such as the presence of secondary bacterial infection.

•    There have been two major outbreaks of highly pathogenic avian influenza in the United States, one in 1924-25, reappearing in 1929, and one in 1983-84. In 2004 there was a minor outbreak in Texas.

•    Mildly pathogenic outbreaks of influenza in poultry occur annually in the United States. These outbreaks are the result of the virus being moved from the natural reservoir (waterfowl) or man made reservoir (live bird markets) and infecting poultry.

What is done about avian influenza in poultry?

•    Avian influenza is reportable to the Board of Animal Health in Minnesota.

•    Minnesota has a cooperative avian influenza control plan in place that includes education, monitoring, reporting, and a responsible response.

•    Flocks in Minnesota are routinely monitored for evidence of influenza infection. Serological tests are conducted at the University of Minnesota Poultry Testing Laboratory in Willmar.

•    Minnesota also has a H5/H7 avian influenza response plan in case H5 or H7 influenza is found here.

 How is avian influenza spread within poultry flocks?

•    Virus is shed in secretions or discharges from the eyes, nose and mouth and in the droppings of infected birds.

•    Within a flock the virus may be spread from bird to bird by shared drinking water or shared feeders that have been contaminated by discharge or droppings or through the air by inhaling of aerosol droplets.

How is avian influenza spread from flock to flock?

•    Transmission from flock to flock is usually by people (through contaminated footwear and clothing) and contaminated equipment involved in production, live-haul or live bird marketing.

•    It can also be spread by introduction of infected birds into a flock or contact with infected wild birds.

•    The first indication of highly pathogenic avian influenza in poultry is sudden deaths, often without many signs of illness. If you witness such an event contact your veterinarian or state veterinarian. In Minnesota contact Dr. Dale Lauer at the Board of Animal Health, 320-231-5170.

•    If you see sick game chickens or pet birds in Minnesota contact your veterinarian or Dr. Dale Lauer.

•    If you see a lot of dead wild birds contact the Minnesota DNR at: Dr. Michelle Powell, Natural Resources Specialist at 651-296-2663 or Mike Don Carlos, Director of Wildlife Programs at 651-259-5202.

•    Contact Dr. Andre Ziegler, 612-624-1974, at the Minnesota Veterinary Diagnostic Laboratory for information on getting suspect birds examined for diagnosis.  The general phone number for the MVDL is 612-625-8787 or 1-800-605-8787.

•    See this link for more info: http://www.aphis.usda.gov/vs/birdbiosecurity/hpai.html

•    If you have dead poultry or pet birds to report you can also call: 1-866-536-7593

Additional information is available from Dr. Dave Halvorson, Extension Veterinarian, at halvo002@umn.edu or 612-625-5292 or  http://www.cvm.umn.edu/ai