Development of antigen capture ELISA for the detection of egg drop syndrome -76 virus in chicken

Egg drop syndrome 76 (EDS-76) is one of the important infectious viral diseases of poultry since it causes considerable drop in egg production. The disease is caused by EDS-76 virus belonging to group III avian adenoviruses. In this study, an antigen capture enzyme linked immunosorbent assay (ELISA) was developed for the detection of egg drop syndrome -76 (EDS-76) virus antigen in tissues collected from the experimentally infected layer birds. Layer birds of20 weeks (Group-I: n=16) were infected with 0.5 ml 104.5 TCID₅₀ of infected duck allantoic fluid oro-nasally. Tissues viz. uterus, spleen and buffy coat were collected from the infected and control birds on 3, 5, 7, 10, 15, 21 and 28 days post infection (DPI). The EDS-76 virus specific antigen could be detected from 3 to 15 DPI in uterus and spleen, and 3 to 10 DPI in bufry coat. The developed ELISA was tested with other viral antigens viz., Fowl adenovirus serotype-4, CELO virus, Infectious Bursal Disease virus, Reovirus, Chicken anaemia virus, and Newcastle disease virus and found specific for the detection of only EDS-76 virus. It could detect upto 5 ng of the purified EDS-76 viral antigen and 4% (w/v) preparation of pooled known positive uterus tissue samples. The antigen capture ELISA can be used for the specific and timely detection of EDS-76 virus in the layer flocks.