Which statement best contrasts infectious and noninfectious diseases?

Which statement best contrasts infectious and noninfectious diseases?

• A. Infectious diseases are contagious and caused by pathogens
• B. Noninfectious diseases are contagious
• C. Infectious diseases never spread
• D. Noninfectious diseases are always fatal

Answer: (A)

Infectious diseases arise from pathogens such as bacteria, viruses, fungi, or parasites, and they can be transmitted from one person to another. Noninfectious diseases are not caused by pathogens and are not spread between people. The best statement captures both aspects of this contrast by noting that infectious diseases are caused by pathogens and can be contagious, whereas noninfectious diseases are not contagious. The other options misstate the nature of contagion or transmission—for example, noninfectious conditions aren’t contagious, infectious diseases can spread, and noninfectious diseases aren’t inherently fatal.

Infectious diseases arise from pathogens such as bacteria, viruses, fungi, or parasites, and they can be transmitted from one person to another. Noninfectious diseases are not caused by pathogens and are not spread between people. The best statement captures both aspects of this contrast by noting that infectious diseases are caused by pathogens and can be contagious, whereas noninfectious diseases are not contagious. The other options misstate the nature of contagion or transmission—for example, noninfectious conditions aren’t contagious, infectious diseases can spread, and noninfectious diseases aren’t inherently fatal.