Survey on antibody against egg drop syndrome-1976 virus among chicken flocks in Japan.

A survey on antibody against egg drop syndrome-1976 virus was carried out with 4,518 sera collected from 667 flocks over a period from 1971 to 1981 in Japan. Antibody-positive sera were initially detected in 1976, and the number of positive sera increased suddenly in 1979, and a total of 270 sera from 23 flocks were positive. The positive flocks consisted of 20 broiler parent flocks belonging to 9 farms and 3 layer flocks belonging to 2 farms. It seemed from the results of this survey that the prevalence of the virus might have been limited in Japan.