Egg Drop syndrome virus (EDSV)
Egg drop syndrome virus (EDSV) is a double-stranded DNA, adenovirus from the Atadenovirus genus which causes egg drop syndrome (EDS) in laying hens. It is also referred to as duck adenovirus serotype 1, because it is believed that the virus originated in ducks. Ducks and other wild waterfowl species are often infected without showing any signs of disease themselves. The first reported outbreak of EDS occurred in domestic laying hens from the Netherlands in 1976.
EDSV is spread horizontally through feces or vertically through the embryonated egg. It spreads slower then other avian adenoviruses, varying from 7 to 17 days until hens present with clinical signs following exposure. The virus is somewhat resistant to heat and may persist for days in the environment, especially in fecal-contaminated water.