Table 2. Retrospective seroprevalence of antibodies to A/chicken/Hong Kong/22-10782/2022 influenza A(H3N8) virus in chicken serum samples collected from affected farms, Hong Kong, China*.
| Farm | Date samples collected | No. | H3N8 HI titer >1:16, no. (%) | H3N8 GMT (95% CI) |
|---|---|---|---|---|
| A | 2022 Feb 16 | 30 | 26 (86.7) | 28.51 (20.01–40.61) |
| B | 2022 Feb 9 | 30 | 2 (6.7) | 1.35 (0.96–1.91) |
| C | 2022 Feb 16 | 30 | 29 (96.7) | 46.31 (31.97–67.09) |
| D | 2022 Feb 24 | 30 | 26 (86.7) | 16 (10.25–24.99) |
*Serologic study was conducted on 28 farms in January‒February 2022. Only data for 4 farms positive for H3N8 virus are shown. GMT, geometric mean titer; HI, hemagglutination inhibition.