Phylogenetic and pathogenic characterization of novel adenoviruses isolated from long-tailed ducks (Clangula hyemalis)

- Novel adenoviruses were isolated from long-tailed ducks.
- Specific primers were developed to screen for adenoviral infections.
- The majority of isolates shared hexon gene similarity with Goose adenovirus A.
- Several adenovirus isolates shared no hexon sequences with any known adenoviruses.
- Experimental mallard infections resulted in lesions similar to those seen in long-tailed ducks.

Novel adenoviruses were isolated from a long-tailed duck (Clangula hyemalis) mortality event near Prudhoe Bay, Alaska in 2000. The long-tailed duck adenovirus genome was approximately 27 kb. A 907 bp hexon gene segment was used to design primers specific for the long-tailed duck adenovirus. Nineteen isolates were phylogenetically characterized based on portions of their hexon gene and 12 were most closely related to Goose adenovirus A. The remaining 7 shared no hexon sequences with any known adenoviruses. Experimental infections of mallards with a long-tailed duck reference adenovirus caused mild lymphoid infiltration of the intestine and paint brush hemorrhages of the mucosa and dilation of the intestine. This study shows novel adenoviruses from long-tailed ducks are diverse and provides further evidence that they should be considered in cases of morbidity and mortality in sea ducks. Conserved and specific primers have been developed that will help screen sea ducks for adenoviral infections.