Characterization of an Avian Adenovirus Associated with Inclusion Body Hepatitis in Day-old Turkeys

SUMMARY. A group I avian adenovirus isolated from day-old turkeys with inclusion body hepatitis (IBH) was identified as turkey adenovirus serotype 2 (TAV2) based on crossneutralization assays and DNA restriction endonuclease analyses. Yolk sac inoculation of embryonated turkey eggs resulted in embryo mortality and significantly (P < 0.01) decreased hatchability compared with sham-inoculated controls. Embryo mortality occurred primarily between day 24 of incubation and the time embryos hatched. Focal necrosis was detected in livers of 11/52 virus-inoculated embryos that died postinoculation and 1/27 hatchlings; in three embryos, areas of necrosis contained intranuclear inclusion bodies. These findings identify the IBH isolate as TAV2, incriminate the virus as a potential cause of suboptimal hatchability in turkeys, and provide additional evidence for causal involvement in IBH. RESUMEN. Nota de investigacion-Caracterizaci6n de un adenovirus aviar asociado con