Nidovirales is an order of viruses with animal hosts.

The bacterium would have lost the genes that were not necessary for living in an animal host.

The virus can be transmitted from the mother mosquito to her eggs, so no animal host is needed to perpetuate it.

Detailed life cycle studies have not been carried out with wild animal definitive hosts.

The most important factor in the development of an emergent disease, to humans, is the ability to pass from animal host to humans.

What kinds of animal hosts do these viruses have?

A larger proportion of face flies on the host will be females, as they have a higher need for protein provided by animal hosts.

Sterols are acquired from the environment, usually as cholesterol from the animal host.

Humans are the only known animal host for this bacterium in vivo.

It is an environmental organism that has no requirement to pass through an animal host in order to replicate.