Bat flu describes influenza A viruses identified in bats. When researchers from the Universidad del Valle and CDC did a study on “small yellow-shouldered bats” in Guatemala in 2009 and 2010, they found the first cases of bat flu there. In Central and South America, numerous species of bats have since been found to carry the bat flu virus.
For these viruses to readily infect and proliferate among humans, they would need to go through considerable alterations. The species of bats that are now thought to carry the bat flu are widespread in Central and South America but are not endemic to the continental United States.