An outbreak of highly pathogenic avian influenza subtype H5N1 in broiler breeders, Korea.
Highly pathogenic avian influenza (HPAI) was diagnosed in broiler breeders, submitted to the National Veterinary Research and Quarantine Service in South Korea. Grossly, the dead breeders had lesions consistent with HPAI, including pancreatic mottling, splenomegaly, pulmonary edema and congestion, and hemorrhages in the mucosa of the proventriculus, gizzard and small intestine, and on the serosal surface. Microscopically, there were necrotized hepatitis and pancreatitis, lymphocytic meningoencephalitis, myocarditis, and interstitial pneumonia. Influenza viral antigen was demonstrated in areas closely associated with histopathologic lesions. The AI virus was isolated from cecal tonsils, feces, trachea, and kidney of the chickens. The isolated virus was identified as the highly pathogenic H5N1, with a hemagglutinin proteolytic cleavage site deduced amino acid sequences of QREKRKKR/GLFGAGLFGAIAG. In order to determine the pathogenicity of the isolate, eight 6-week-old specific pathogen free chickens were inoculated intravenously with the virus, and all the birds died within 24 hr after inoculation. This is the first report of an outbreak of HPAI in the chickens in South Korea.
Kwon
Yong-kuk
YK
Avian Disease Division, National Veterinary Research and Quarantine Service, Anyang, Korea.
Sung
Haan-woo
HW
Joh
Sung-jun
SJ
Lee
Youn-jeong
YJ
Kim
Min-chul
MC
Choi
Jun-gu
JG
Lee
Eun-kyoung
EK
Wee
Sung-Hwan
SH
Kim
Jae-hong
JH
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004196:Disease Outbreaks / Q000662:veterinary*; D006386:Hemagglutination Tests / Q000662:veterinary; D007150:Immunohistochemistry / Q000662:veterinary; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000473:pathology*; D007723:Korea; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000453:epidemiology* / Q000473:pathology* / Q000821:virology*