First survey of the occurrence of duck enteritis virus (DEV) in free-ranging Polish water birds.

Duck plague (DP) caused by anatid herpesvirus 1, also called duck enteritis virus (DEV), presents one of the most important concerns in mass waterfowl production. Apart from geese and ducks, free-ranging water birds are the most notorious infection carriers. The epidemiology of DEV in Western Europe remains unknown. Therefore, it was reasonable to conduct a study on its occurrence using modern but simple real-time loop-mediated isothermal amplification (LAMP). Analysis of 132 field isolates showed the presence of DEV in 96 birds (72.7 %), and it was found predominantly in wild ducks (Anas platyrhynchos) and mute swans (Cygnus olor). This virus was also found in graylag geese (Anser anser), tundra bean geese (Anser fabalis), and grey herons (Ardea cinerea). The results were recorded as green colour of positive samples, fluorescence under ultraviolet light, and florescent curves in a real-time PCR system. This study indicates the high prevalence of DEV among free-ranging water birds in Poland and the possible transmission to other birds settling in the water environment. This is the first report of DEV detection among free-ranging water birds in Poland.