First reported outbreak of Duck atadenovirus A tracheobronchitis in 3-week-old ducklings in Québec including whole genome sequence of the virus

摘要

Duck atadenovirus A, also known as Duck adenovirus 1 (DAdV-1), is a member of the genus Atadenovirus (1). This virus is also responsible for the Egg Drop Syndrome (EDS) of laying hens (2). This syndrome is listed as an immediately notifiable disease in Canada, because it is considered as an exotic disease for which there are no control or eradication programs (3). Although this virus has never been reported in commercial chicken production in Canada, DAdV-1 was identified in 2009 in 2 Muscovy duck farms in Ontario (4). An adenovirus was also isolated in goslings with respiratory clinical signs in Saskatchewan in 1992, but the adenovirus species was undetermined (5,6). Antibodies to DAdV-1 have been detected in numerous wild waterfowl in North America, up to 42% in sampled ducks, suggesting it is widespread on the continent and that these birds act as reservoirs (7). Overall, DAdV-1 seems weakly pathogenic for ducks and geese because most infections are asymptomatic, and the rare reports of clinical signs always imply very young (4 to 20 d of age) ducklings and goslings. When sick, these birds show gasping, dyspnea, coughing, and/or sneezing and mortality is moderate (2% to 7%) (4–6). DAdV-1 is substantially more pathogenic in chicken layers, in which it is associated with a severe drop in egg production that could last for 4 to 10 wk, and the laying of thin-shelled, soft-shelled, or shell-less eggs (2).