Domestic Ducks and
H5N1 Influenza Epidemic, Thailand
In addition to causing 12 human deaths and 17 cases of human infection,
the 2004 outbreak of H5N1 influenza virus in Thailand resulted in the death
or slaughter of 60 million domestic fowl and the disruption of poultry production
and trade. After domestic ducks were recognized as silent carriers of H5N1
influenza virus, government teams went into every village to cull flocks
in which virus was detected; these team efforts markedly reduced H5N1 infection.
Here we examine the pathobiology and epidemiology of H5N1 influenza virus
in the 4 systems of duck raising used in Thailand in 2004. No influenza
viruses were detected in ducks raised in closed houses with
high biosecurity. However, H5N1 influenza virus was prevalent among ducks
raised in open houses, free-ranging (grazing) ducks, and backyard
Songserm et al
("bird flu") and the significance of its transmission to humans
The disease in birds: impact and control measures Avian influenza is an
infectious disease of birds caused by type A strains of the influenza virus.
The disease, which was first identified in Italy more than 100 years ago,
occurs worldwide. WHO
Key Facts About
Avian Influenza (Bird Flu) and Avian Influenza A (H5N1) Virus
Bird flu 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, bird flu is very contagious among birds and can make some domesticated
birds, including chickens, ducks, and turkeys, very sick and kill them.
Avian Influenza (AI) or "Bird Flu" is a highly contagious viral
infection which can affect all species of birds and can manifest itself
in different ways depending mainly on the pathogenicity of the virus involved
and on the species affected.