Airborne transmission of infectious agents

Airborne transmission is one of the different ways infectious diseases spread. Airborne transmission often has an environmental source, as for legionellosis. It can also have an infectious human source. For a given infectious agent, the mode of transmission can be multiple. This is the case for influenza that can be spread by airborne transmission but also directly through respiratory secretion and indirectly through the contaminated environment. If airborne transmission may occur from person to person, it is most often a transmission from or through the environment.