On the basis of these changes, the disease was designated duck hemorrhagic ovaritis.
To further confirm flavivirus as the causative agent of duck hemorrhagic ovaritis, we used PCR to test the isolate and clinical samples with forward primer Usu5454f (5'-ATGGATGAAGCYCATTTCAC-3') (5) and a newly designed reverse primer 5861R (5'-CCAAAGTTGGCYCCCATCTC-3').