Avian Flu (Bird Flu)
What is avian influenza?
Avian influenza virus (AIV) is a disease that affects 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. 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. Wild land 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 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 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 were more than 220 cases of HPAI and approximately 47 million birds affected. Minnesota and Iowa have experienced the largest number of cases (105 and 74, respectively). All the 2015 HPAI cases in the Midwest consisted of the H5N2 subtype except the case in Indiana. The subtype detected in Indiana in spring 2015 was the Eurasian H5N8 subtype, which had been previously detected only along the West Coast.
What is the current status of avian influenza in Indiana?
In May 2015, avian influenza virus (AIV) was detected in a backyard, mixed poultry flock in Whitley County, Indiana. The Board of Animal Health (BOAH) confirmed that approximately two-thirds of the flock was positive for a highly pathogenic subtype of AIV, H5N8. The entire flock was depopulated and, after extensive surveillance and testing by both BOAH and the Division of Fish & Wildlife (DFW) in both domestic and wild birds within a 10 km (6.2 mi) radius buffer around the positive flock, BOAH lifted the quarantine for the Whitley County case.
On Jan. 15, 2016, AIV was detected in a commercial turkey facility in Dubois County, Indiana. The birds within the facility tested positive for highly pathogenic avian influenza subtype H7N8, which was a new North American subtype (different from the strain in the upper Midwest in spring 2015). A 10 km control area and a 20 km surveillance zone were established around the positive facility. Subsequent testing within the control area by BOAH and the USDA’s Animal and Plant Health Inspection Service (APHIS) identified eight turkey facilities that tested positive for a low pathogenic strain of H7N8 avian influenza. While BOAH and APHIS tested domestic flocks and wildlife on the positive premises, the DFW began testing wild birds within both control area and surveillance zone.
1. No additional facilities tested positive for AIV. Eleven poultry facilities were depopulated within the control area due to detection of the highly pathogenic H7N8 (one facility), detection of the low pathogenic H7N8 (in eight commercial turkey facilities), or proximity (one commercial turkey facility and one commercial chicken facility) to the positive highly pathogenic H7N8 facility.
2. No wild birds sampled by DFW tested positive for the highly pathogenic subtypes H5 or H7. The DFW tested 126 wild birds both within and outside of the control area and surveillance zone.
3. Surveillance continued within the established control area/surveillance zone by all entities until BOAH lifted the quarantines.
What AIV surveillance is DNR Fish & Wildlife doing?
Personnel with DFW continue to conduct opportunistic sampling of wild birds across the state for AIV. Opportunistic sampling consists of collecting dead wild birds that meet specific criteria. DFW staff collects individual waterfowl, shorebirds, gallinaceous birds (grouse, pheasant, wild turkeys) and raptors that have died of unknown causes. In addition, DFW staff collects songbirds that have died of unknown causes during a mortality event of at least five birds at one time.
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 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: DNR Fish & Wildlife: Sick or dead wildlife can be reported online at on.in.gov/sickwildlife.