Table 1.
Infectivity, lethality, and transmission results from turkeys and chickens inoculated with the US 2020 H7N3 LPAIVs and HPAIV.
| Bird Species | Virus | Dose (log10 EID50) | Inoculated | Contact Exposed | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of Birds Shedding Virus/Total | No. of Dead Birds/Total (MDT) 1 | No. of Birds HI Positive/Total (Mean HI Titer) 2 | No. of Birds Infected/Total 3 | BID50 (log10) 4 | No. of Birds Shedding Virus/Total | No. of Dead Birds/Total (MDT) | No. of Birds HI Positive/Total (Mean HI Titer) 2 | No. of Birds Infected/Total 3 | |||
| Turkeys | LPAIV-1 | 2 | 0/4 | 0/4 | 0/4 (<3.0) | 0/4 | 2.5 | na | na | na | na |
| 3 | 5/5 | 0/5 | 5/5 (9.4) | 5/5 | 2/2 | 0/2 | 2/2 (10) | 2/2 | |||
| 5 | 5/5 | 0/5 | 5/5 (9.4) | 5/5 | 2/2 | 0/2 | 2/2 (10) | 2/2 | |||
| LPAIV-2 | 2 | 5/5 | 0/5 | 5/5 (8.0) | 5/5 | <2 | na | na | na | na | |
| 3 | 5/5 | 1/5 5 | 4/4 (6.5) | 5/5 | 2/2 | 1/2 5 | 1/1 (8.0) | 2/2 | |||
| 5 | 5/5 | 0/5 | 5/5 (7.6) | 5/5 | 2/2 | 0/2 | 2/2 (6.0) | 2/2 | |||
| HPAIV | 2 | 5/5 | 5/5 (2.4) | na | 5/5 | <2 | na | na | na | na | |
| 4 | 5/5 | 5/5 (2.2) | na | 5/5 | 2/2 | 2/2 (3) | na | 2/2 | |||
| 6 | 5/5 | 5/5 (2.0) | na | 5/5 | 2/2 | 2/2 (3) | na | 2/2 | |||
| Chickens | LPAIV-1 | 2 | 0/5 | 0/5 | 0/5 (<3.0) | 0/5 | 5.7 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 |
| 3 | 0/5 | 0/5 | 0/5 (<3.0) | 0/5 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
| 5 | 1/8 | 0/8 | 0/5 6,7 (<3.0) | 1/8 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
| 6 | 8/8 | 0/8 | 5/5 6 (6.0) | 8/8 | 3/3 | 0/3 | 1/3 (5.0) | 3/3 | |||
| LPAIV-2 | 2 | 0/5 | 0/5 | 0/5 (<3.0) | 0/5 | 5.4 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |
| 3 | 1/5 | 0/5 | 1/5 (3.0) | 1/5 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
| 5 | 1/8 | 0/8 | 0/5 6,7 (3.0) | 1/8 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
| 6 | 8/8 | 0/8 | 5/5 6 (4.5) | 8/8 | 3/3 | 0/3 | 1/3 (7.0) | 3/3 | |||
| HPAIV | 2 | 1/5 | 1/5 (1) | 0/5 (<3.0) | 1/5 | 3.7 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |
| 4 | 5/5 | 5/5 (1.6) | na | 5/5 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
| 6 | 8/8 | 8/8 (1.6) | na | 8/8 | 0/3 | 0/3 | 0/3 (<3.0) | 0/3 | |||
1 MDT, mean death time, number of dead birds × dpi/total dead birds expressed as dpi (days post-inoculation), or dpc, (days post-contact). 2 Mean HI titers for birds that survived (14 dpi or 13 dpc). Titer expressed in geometric mean titers (GMT log2). Samples with titers < 3.0 log2 GMT were considered negative. 3 Inoculated or contact birds were considered infected if they shed virus and/or were positive for antibodies at 14 dpi or 13 dpc. 4 BID50: 50% bird infectious dose. 5 Birds died of undetermined causes. qRT-PCR positive for at least two time points. 6 The number of birds is reduced due to necropsy at 2 dpi. 7 One of the necropsied birds were qRT-PCR positive for at least two time points but serology was unavailable because the bird was euthanized at 2 dpi. na: not applicable.