Group I avian adenovirus and avian adeno-associated virus in turkey poults with inclusion body hepatitis

Abstract

Adenoviral inclusion body hepatitis (IBH) is rare in turkeys. Avian adenovirus group I and avian adeno-associated virus were isolated from the liver and pooled intestinal samples from 4-week-old turkey poults on two different ranches experiencing increased mortality. Grossly, a few birds from each ranch had a slightly enlarged liver with white foci of necrosis randomly scattered throughout. Microscopically, there was coagulative necrosis of hepatocytes with infiltration of a mixed population of inflammatory cells composed of lymphocytes, plasma cells, heterophils, and macrophages. In these livers, there were numerous basophilic intranuclear inclusion bodies in the hepatocytes. Transmission electron microscopy of the liver revealed 70 to 75 nm viral particles with icosahedral morphology consistent with adenovirus scattered throughout the nucleus of hepatocytes. All of the birds were serologically negative for haemorrhagic enteritis virus infection. Of some 5000 submissions over a 12-year period of turkey poults aged between 1 day and 10 weeks, only two single birds within two submissions had IBH.