Outbreak of gizzard erosion associated with fowl adenovirus infection in Korea.

The pathogenicity of a fowl adenovirus serotype-1 (FAdV-1, K181 strain) isolated from a case of gizzard erosion in layer chickens was investigated in specific-pathogen-free (SPF) chicks. One-week-old SPF chicks were inoculated orally or intramuscularly with the isolate of FAdV-1 and euthanized for necropsy at 7, 14, and 21 d postinoculation. Although there were no clinical signs after inoculation, gizzard erosions were observed grossly and the virus was recovered from the gizzards in the inoculated chickens. Histologically, in the chickens that were infected orally, the lesions found in the gizzard consisted of severe degeneration and necrosis of glandular epitheliums and eosinophilic inclusion bodies. These results indicate that the Korean FAdV-1 isolate could induce gizzard lesions in chickens. Moreover, the present investigation reproduced an outbreak of gizzard erosion caused by FAdV-1 infection and, for the first time, described the isolation of FAdV-1 from chickens in Korea. These findings provide important information on the epidemiology and pathogenesis of FAdV-1 infection in chickens.