Section 1. Avian Influenza Facts
- Source and Transmission
- Agent Characteristics
- Virus Survival
- Clinical Signs in Birds
- HPAI H5N1
- Human Concerns
Avian Influenza Biosecurity for Backyard Flock Owners
Avian Influenza Outbreaks in the U.S.
While HPAI H5N1 has not been reported in the U.S. as of February 2011, outbreaks of other HPAI subtypes have occurred throughout the country. To date, there have been four outbreaks in the U.S. of HPAI occurring in 1924, 1983, 2004, and 2014. Several low pathogenic outbreaks have resulted in mass depopulations of poultry as well. Many of these cases are believed to have resulted from contact with AI-infected live bird markets and sharing equipment between farms.2 |
Documented HPAI in Poultry6,22
Documented LPAI in Poultry6,22
Year |
Location |
Strain |
Losses |
1924-25 |
USA |
Unknown |
Unknown |
1983-84 |
PA, USA |
H5N2 |
17 million |
2004 |
TX, USA |
H5N2 |
9,000 |
2014-2015 | USA | H5N2, H5N8, H5N1 | 49 million |
Documented LPAI in Poultry6,22
Year |
Location |
Strain |
Losses |
1978-1995 |
MN |
Various LPAI |
1199 Farms |
1995 |
MN | H9N2 |
178 Farms |
1995 |
UT |
H7N3 |
2 million (60 Farms) |
2002 |
VA |
H7N2 |
4.7 million (197 Farms) |
2004 |
DE, MD, PA |
H7N2, H2N2 |
400,000 |