3.4 Positive detection of viral RNA in embryos and ducklings
101 vitelline membranes, 91 dead embryos and 263 duckling spleen samples were collected in the artificial infection experiment, and qPCR was used to detect viral RNA. Among the samples detected, 18 of 82 yolk membrane samples, 33 of 88 dead embryo samples, and 139 of 141 duckling spleen samples were detected positive for N-DRV. When these two infection methods, the positive rate of viral RNA in the oral administered group was higher than that in the intramuscular injection group. No virus RNA was detected in the control group. Detailed detection data was presented in Table 2.