Identification of Adeno-associated Virus in Muscovy Ducks with Chronic Diarrhea

Adeno-associated viruses (AAVs) are defective members of the genus Dependoparvovirus. Waterfowl parvoviruses, another member of the Dependoparvovirus, were found to be the closest relative of AAVs. This study was performed to identify the genetic changes that may occur to goose parvovirus (GPV) in one Muscovy duck flock that was observed for 12 weeks after the virus was isolated. Persistent watery diarrhea and wing deformity were the common signs. Cloacal swabs were collected from diseased ducks. Unexpectedly, the identified virus was an AAV. The closest strains were duck AAVs at the nucleotide level, identified in Australia and China. Meanwhile, only 52.3% of nucleotide identity was shared with the GPV strain, previously identified from this flock. Duck adenovirus (DAdV) could not be identified in the samples. This study is one of the first studies in which genetic changes of GPV were tracked. In addition, emerging duck AAV from GPV is suggested, which will be useful for future virus classification.
Keywords: Adeno-associated virus, Chronic diarrhea, Muscovy ducks