Capable of being transmitted from one person to another, directly or indirectly, through an infectious agent.
A contagious disease can spread between people through routes such as respiratory droplets or aerosols, direct contact, contaminated objects, or other forms of transmission, depending on the infectious agent.
The degree of contagiousness varies between diseases and can also change depending on factors such as the stage of infection, route of transmission, and environmental conditions.
QUICK FACT
Contagious does not mean “inevitably transmitted.” A contagious infection can be difficult or easy to spread depending on how exposure occurs and how susceptible other people are.
COMMONLY CONFUSED WITH
Infectious: An infectious disease is caused by an infectious agent; a disease can be infectious without being readily transmitted from person to person.
SEE ALSO