What is a disease spread from person to person by contact called?

The term that specifically describes a disease spread from person to person by contact is known as contagion. Contagion refers to the way diseases can easily be transmitted through direct contact between individuals. This encompasses various forms of transmission, such as touching, coughing, or sneezing, which can result in the spread of infectious agents.

Infection, while related, refers more broadly to the invasion and growth of microorganisms within the body and does not exclusively imply person-to-person transmission. Transmission encompasses the overall process by which the disease spreads, which could happen through various means, not solely through direct contact. Inoculation refers to the introduction of an antigenic substance or vaccine into the body to stimulate an immune response, which is a separate concept. Therefore, contagion is the most accurate term to describe diseases that are passed between people through contact.