Sentence examples for both birds were negative from inspiring English sources

Fecal PCR testing showed that both birds were negative on days 33 and 43.

However, both the pre- and post-challenge sera of rNDV-HA- and rNDV-HAF-vaccinated birds were negative for AIV NP antibody by AIV NP ELISA.

Cloacal swabs from juvenile birds were real-time RT-PCR positive at 3 dpi; swabs from adult birds were negative (oropharynegeal swabs not tested).

†Deaths occurred in sparrows and grackles but not thrushes and chickens; thrushes and chickens were euthanized on 21 and 7 dpi, respectively, and tissues from these birds were negative for infectious WNV with the exception of 1 chicken-derived skin sample (102.0 PFU/0.5 cm).

One tracheal sample from an apparently healthy tree sparrow was positive for the novel subtype H7N9 virus, whereas the cloacal swab samples from this bird were negative.

Both birds are recovering after being treated with IV fluids.

So we detected HEV in only two birds while the other two birds' results were negative.

Both tests were negative.

Both controls were negative.

However, all birds experimentally exposed were negative for schistosome infection.

Oral swabs from all dead birds were tested at the Wisconsin Veterinary Diagnostic Laboratory (Madison, WI, USA) for both agents and were negative.