Egg drop syndrome virus (EDSV) was differentially diagnosed using
polymerase chain reaction, and the strains were isolated from tracheas and lungs by
inoculation of 10-day-old embryonated duck eggs. The virus isolates were designated
strain D11-JW-012 and D11-JW-017. The clinical and pathological signs were reproduced
by intra-tracheal inoculation of the isolates in 3-day-old ducklings. Although the two
isolates produced similar clinical signs, pathological lesions and ciliostasis, the D11-JW-
017 strain resulted in more severe clinical signs with progressive symptoms compared to
those of D11-JW-012 strain-infected ducklings. We suggest that different EDSV strains
with mild or severe to moderate pathogenicity coexist and have potential risks in poultry.
Hereby, we report an EDSV infection in ducklings.