Table 1.
Detection of H9N2 viruses in SPF chicken swabs1.
| Virus titer (log10 EID50/0.1 mL, mean ± SD) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| Species | Group | Route | 1 dpi | 3 dpi | 5 dpi | 7 dpi | 10 dpi | 14 dpi | HI titer (log2, mean ± SD) |
| A/chicken/Korea/LBM261/2020 (H9N2) | Inoculated | OP | 4.7 ± 0.3 (8/8) | 4.8 ± 0.3 (8/8) | 3.0 ± 0.7 (5/5) | - (0/5) | - (0/5) | - (0/5) | 6.0 ± 0.7 (5/5) |
| CL | - (0/8) | 2.0 (1/8) | 1.1 (1/5) | - (0/5) | - (0/5) | - (0/5) | |||
| Contact | OP | - (0/3) | 4.5 ± 0.5 (3/3) | 4.5 ± 0.5 (3/3) | 2.5 ± 0.7 (3/3) | - (0/3) | - (0/3) | 6.0 ± 1.0 (3/3) | |
| CL | - (0/3) | - (0/3) | - (0/3) | - (0/3) | - (0/3) | - (0/3) | |||
| A/chicken/Korea/LBM294/2018 (H9N2) | Inoculated | OP | 2.8 ± 0.2 (8/8) | 2.4 ± 0.3 (7/8) | 2.3 ± 0.1 (3/5) | 1.6 ± 0.2 (4/5) | - (0/5) | - (0/5)- | 6.4 ± 0.9 (5/5) |
| CL | - (0/8) | 3.7 (1/8) | 5.0 ± 0.3 (2/5) | 5.2 ± 0.1 (2/5) | 1.7 (1/5) | - (0/5) | |||
| Contact | OP | - (0/3) | - (0/3) | 1.1 (1/3) | 3.4 ± 0.4 (3/3) | 3.2 ± 0.8 (3/3) | - (0/3) | 6.7 ± 0.6 (3/3) | |
| CL | - (0/3) | - (0/3) | - (0/3) | 1.4 ± 0.1 (2/3) | 5.1 ± 0.4 (2/3) | 2.1 (1/3) | |||
Abbreviations: CL, cloacal swab sample; DPI, days postinfection; EID50, 50% egg infective dose; OP, oropharyngeal swab sample.
1
The number of affected birds/birds per group is indicated in parenthesis. Eight birds were inoculated intranasally with 106.0 EID50/0.1 mL of each virus and 3 birds (contact group) were co-housed with the infected birds. Three birds inoculated with each of the viruses were euthanized for autopsy on d 3 postinfection. Seroconversion was measured in a hemagglutinin-inhibition assay at the end of the experimental period.