1. The Bunyaviridae are a very large family of single-strand, enveloped RNA viruses (more than 300 viruses) and consists of five genera of viruses: OrthoBunyavirus, Phlebovirus, Nairovirus, Hantavirus, and Tospovirus (Tospoviruses infect only plants).

2. Specific rodents are the principal hosts of the hantaviruses including the hispid cotton rat (Sigmodon hispidus) in southern Florida, which is the principal host of Black Creek Canal virus., The deer mouse (Peromyscus maniculatus) in Canada and the Western United States is the principal host of Sin Nombre virus.

3. These include increases in the frequency and duration of smog and heat waves, deterioration of air and water quality, and changes to the geographic distribution of fauna (e.g. broader range of mosquitoes and rodents propagating illnesses such as the West Nile virus and hantavirus) and flora (e.g. a broader range of allergenic plants).