Avian Influenza
Avian influenza is an
infection caused by avian (bird) influenza (flu)
viruses. These flu viruses occur naturally among
birds. Wild birds worldwide carry the viruses in
their intestines, but usually do not get sick
from them. However, avian influenza is very
contagious among birds and can make some
domesticated birds, including chickens, ducks,
and turkeys, very sick and kill them.
Infection with avian
influenza viruses in domestic poultry (chickens,
turkeys, etc.) causes two main forms of
disease. The “low pathogenic” form may go
undetected and usually causes only mild symptoms
(such as ruffled feathers and a drop in egg
production). However, the highly pathogenic form
spreads more rapidly through flocks of poultry.
This form may cause disease that affects
multiple internal organs and has a mortality
rate that can reach 90-100% often within 48
hours.
Human Infection with Avian
Influenza Viruses
Usually, “avian influenza
virus” refers to influenza A viruses found
chiefly in birds, but infections with these
viruses can occur in humans. The risk from avian
influenza is generally low to most people,
because the viruses do not usually infect
humans. However, confirmed cases of human
infection from several subtypes of avian
influenza infection have been reported since
1997. Most cases of avian influenza infection in
humans have resulted from contact with infected
poultry (domesticated chicken, ducks, and
turkeys) or surfaces contaminated with
secretion/excretions from infected birds. The
spread of avian influenza viruses from one ill
person to another has been reported very rarely,
and transmission has not been observed to
continue beyond one person. Since 2003 there
have been about 200 cases of Avian influenza
worldwide, with more than half resulting in
death. No cases in humans have occurred at this
date (5/4/06).
Local Information
State, National & World Avian
Influenza Information
Avian Influenza Activity
(through June 2007)
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