Possible circulation of H5N1 avian influenza viruses in healthy ducks on farms in northern Vietnam.
To estimate the prevalence of influenza A subtype H5N1 viruses among domestic ducks in the period between October and November 2006 when H5N1 outbreaks had been absent, 1106 healthy ducks raised in northern Vietnam were collected. Inoculation of all throat and cloacae samples into embryonated eggs resulted in the isolation of subtype H3N8 in 13 ducks, but not H5N1 viruses. Serological analyses demonstrated that five ducks (0.45%) solely developed H5N1 subtype-specific hemagglutinin-inhibiting and neuraminidase-inhibiting antibodies together with anti-non-structural protein 1 antibodies. The results suggested that the ducks were naturally infected with H5N1 viruses when obvious H5N1 outbreaks were absent.
Takakuwa
Hiroki
H
Avian Influenza Research Centre, Kyoto Sangyo University, Kamigamo-Motoyama, Kita, Kyoto 603-8555, Japan.
Yamashiro
Tetsu
T
Le
Mai Q
MQ
Phuong
Lien S
LS
Ozaki
Hiroichi
H
Tsunekuni
Ryota
R
Usui
Tatsufumi
T
Ito
Hiroshi
H
Yamaguchi
Tsuyoshi
T
Ito
Toshihiro
T
Murase
Toshiyuki
T
Ono
Etsuro
E
Otsuki
Koichi
K
D000818:Animals; D004372:Ducks; D053124:Influenza A Virus, H5N1 Subtype / Q000378:metabolism / Q000502:physiology*; D005585:Influenza in Birds / Q000635:transmission* / Q000821:virology*; D014744:Vietnam; D014764:Viral Proteins / Q000378:metabolism
D014764:Viral Proteins