Avian Flu (Bird Flu)
What is avian influenza?
Avian influenza or avian influenza virus (AIV) is a viral disease that can affect bird species throughout the world. Birds get the flu like other wildlife and humans do. There are many subtypes or strains of AIV based on a combination of two proteins, H and N. Avian influenza viruses are further classified based on their ability to produce disease and mortality in poultry. Therefore, highly pathogenic subtypes (HPAI) produce disease and are often fatal in poultry, while low pathogenic subtypes (LPAI) are often asymptomatic or mildly symptomatic in poultry.
What animals get avian influenza?
Avian influenza viruses affect wild and domestic bird species, primarily waterfowl, domestic poultry and raptors. The virus can quickly decimate an entire flock of poultry. Raptors can become infected by eating infected prey or by coming in contact with surfaces that are contaminated with the virus. Some subtypes of AIV can affect mammals such as pigs, cats, horses, dogs and ferrets, as well as humans. Terrestrial wild birds (such as birds that use backyard feeders) typically are not affected by AIV.
What is the current status of avian influenza?
Three subtypes of AIV currently have been detected in the United States.: H5N8, H5N1 and H5N2. H5N8 is a Eurasian subtype initially detected on the West Coast in wild birds in December 2014. H5N1 and H5N2 are novel, mixed-origin subtypes of the highly pathogenic H5N8 Eurasian subtype and low pathogenic North American subtypes. Both H5N1 and H5N2 were also detected along the West Coast in December 2014. This new H5N1 subtype is not the same Eurasian subtype found in Asia in 1996 that caused human illness. By March 2015, H5N2 was detected in the Midwest and, as of June 9, 2015, 21 states reported HPAI. There have been approximately 228 cases of HPAI and approximately 47 million birds affected. Minnesota and Iowa have experienced the largest number of cases (105 and 74, respectively). All of the HPAI cases in the Midwest have consisted of the H5N2 subtype except the HPAI case identified in Indiana. The subtype detected in Indiana was the Eurasian H5N8 subtype which had been detected only along the West Coast.
What is the current status of avian influenza in Indiana?
HPAI, subtype H5N8, was detected in May 2015 in a backyard, mixed-poultry flock. The Board of Animal Health (BOAH) confirmed the H5N8 subtype in approximately two-thirds of the flock. The entire flock was depopulated and surveillance for AIV was conducted by BOAH, U.S. Department of Agriculture Animal and Plant Health Inspection Wildlife Services (WS) and the Indiana DNR Division of Fish & Wildlife (DFW). BOAH and WS conducted surveillance on poultry within a 10 kilometer radius (buffer) around the infected flock, and DFW conducted surveillance on wild birds within the same area. All additional samples (including wild bird samples) from within the 10-kilometer buffer tested negative for AIV. Sampling continued for approximately a month after AIV was initially detected in the backyard flock, when BOAH lifted the quarantine for the area. There have been no additional detections of AIV in Indiana.
What AIV surveillance is DNR Fish & Wildlife doing?
DFW personnel are conducting not only active surveillance of wild birds around the AIV-infected site but also passive sampling throughout the state, and partnering with BOAH and WS to conduct additional sampling during waterfowl banding. Passive sampling consists of collecting dead birds that die of unknown causes from various areas around the state. Individual waterfowl or raptors that die of unknown causes are collected and submitted for AIV testing. Additionally, DFW will collect songbirds that die during a mortality event that numbers at least five birds at one time. The public may contact DFW at 812-334-1137 or email the division at dfwinput@dnr.IN.gov if they find a dead waterfowl, a raptor, or a mortality event of five or more songbirds.
The DFW has a map that identifies the locations of wild birds that have been tested for AIV. This map will be updated periodically based on sampling efforts.
What is the risk to people?
The Center for Disease Control (CDC) considers the risk to people from these HPAI viruses to be low. To date, no human HPAI infections have been detected in the United States. The United States has a strong AIV surveillance program that has been in place for many years. Federal, state and industry partners respond quickly to outbreaks and follow five steps: 1) Quarantine, 2) Eradicate, 3) Monitor, 4) Disinfect, and 5) Test.
What are the signs of HPAI in birds?
Clinical signs of HPAI include one or more of the following:
- Sudden death
- Lack of energy and appetite
- Decrease in egg production; soft-shelled or misshaped eggs
- Swelling of the head, eyelids, wattles, hocks and comb
- Purple discoloration of wattles, combs and legs
- Nasal discharge, cough, sneezing, lack of coordination, and diarrhea
How is HPAI spread?
Once introduced, HPAI can spread quickly through various vectors that include birds, manure, equipment, vehicles, egg flats, crates, people’s clothing and shoes, water, and potentially feed. Research continues to determine if there are other vectors. AIV can remain viable for long periods of time in water and at moderate temperatures. The virus can survive indefinitely in frozen material.
How can you prevent the spread of AIV?
Practice good biosecurity! Do not feed wild birds, especially waterfowl. If you come into contact with a wild bird that appears unhealthy, wash your hands with soap and water, and change clothing and shoes before contacting a domestic flock or captive birds.
Report sick birds or unusual bird deaths to state/federal officials through the following:
Poultry: BOAH healthy bird hotline: 1-866-536-7593
Wild Birds: Indiana DNR Fish & Wildlife Division: 1-812-334-1137 / dfwinput@dnr.IN.gov
For additional information about avian influenza, visit BOAH at in.gov/boah/2390.htm or the USDA APHIS website at www.aphis.usda.gov/animal_health/birdbiosecurity