Georgia has reported cases of bird flu in three flocks. Here's a closer look at the virus, where it is, and how dangerous it is.

Bird flu, also called avian influenza, is a virus that primarily impacts poultry flocks. It is usually passed onto them by migratory birds. The virus can cause birds to be lethargic, and suffer from respiratory issues like swollen eyelids and nasal discharge. In severe cases, the virus leads to death.

Credit: NASA's Goddard Space Flight Center One state health worker called it "the largest documented outbreak in U.S. history." As the bird flu continues to spread across the United States, this map show the extent of the outbreak.