It is thought to have been a species infecting birds.

The people who were ill showed symptoms of the disease and they lived in counties where dead birds infected with the virus have been found.

This type of influenza virus can also infect humans and birds.

The virus, which mainly infects birds, horses and people, has already begun to show itself.

Subsequently, many polyomaviruses have been found to infect birds and mammals.

At that time nine subtypes were known to infect mammals and birds, all of which had been found in humans.

Most bird flu viruses can only infect other birds.

Just to refresh your memory, bird flu is a virus that usually infects only birds.

They mainly infect aquatic birds, but often infest fish as larvae.

Indeed, she sang her sentences, and in so charming a way that she sometimes seemed a delicate bird infected with spring.