Table 2. Clinical symptoms, gross lesions and virus distribution in tissue samples of HPAIV H5N8B infected groups and contact animals.
| Group | Infection | Clinical symptoms | Pathology: gross lesions | Virus detection by PCR | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HPAIV H5N8B | Green diarrhoea | Depression | Conjunctivitis | Nasal/eye discharge | Facial edema | Neurological symptoms (imbalance, shaky motion, torticollis) | Death | Macula feet | Lung hyperemia | Liver necrosis | Liver | Lungs | Cloaca | Intestine | Nasal conchae | Brain | Quill | |
| Seropositive mallards | 0 dpi + 21 dpi | 2/7 | 0/7 | 0/7 | 1/7 | 0/7 | 0/7 | 1/7 | 0/7 | 1/7 | 1/7 | 1/7 (++++) | 1/7 (++++) | 1/7 (++) | 1/7 (++) | 1/7 (++) | 1/7 (+++) | 1/7 (++) |
| Mallard contact ducklings | contact 2 dpi | 0/4 | 3/4 | 1/4 | 2/4 | 0/4 | 0/4 | 3/4 | 1/4 | 0/4 | 2/4 | 3/4 (++++) | 3/4 (+++) | 3/4 (++) | 3/4 (++) | 3/4 (+++) | 3/4 (+++) | 3/4 (+++) |
| Mallard contact ducklings | contact 23 dpi | 0/4 | 2/4 | 0/4 | 0/4 | 0/4 | 1/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 | 0/4 |
| Seronegative Pekin ducks | 0 dpi OR 21 dpi | 4/10 | 5/10 | 0/10 | 3/10 | 2/10 | 4/10 | 10/10 | 1/10 | 4/10 | 7/10 | 10/10 (+++) | 10/10 (+++) | 10/10 (++) | 10/10 (++) | 10/10 (++) | 10/10 (++) | 10/10 (++) |
| Pekin contact ducklings | contact 2 dpi | 1/4 | 2/4 | 0/4 | 0/4 | 0/4 | 2/4 | 4/4 | 1/4 | 2/4 | 3/4 | 4/4 (+++) | 4/4 (+++) | 4/4 (++) | 4/4 (++) | 4/4 (++) | 4/4 (++) | 4/4 (++) |
Dpi, days post infection; dpc, days post contact; average Cq values: ++++, 15 < Cq <20; +++,20 < Cq < 25; ++,25 < Cq < 30; +,30 < Cq < 35