A contagious disease is defined as a disease that

A contagious disease is defined as a disease that

• A. Spreads from person to person.
• B. Is always fatal.
• C. Is limited to animals.
• D. Is non-transmissible.

Answer: (A)

Contagious refers to a disease’s ability to spread from one person to another. This transmission can occur through direct contact, respiratory droplets, or other close-contact routes, which is why the disease is considered contagious. So the statement that best describes a contagious disease is that it spreads from person to person. It doesn’t have to be fatal—many contagious diseases are mild or treatable—nor is it limited to animals, and contagious implies transmissibility, not non-transmissibility.

Contagious refers to a disease’s ability to spread from one person to another. This transmission can occur through direct contact, respiratory droplets, or other close-contact routes, which is why the disease is considered contagious. So the statement that best describes a contagious disease is that it spreads from person to person. It doesn’t have to be fatal—many contagious diseases are mild or treatable—nor is it limited to animals, and contagious implies transmissibility, not non-transmissibility.