Which term refers to infection caused by introduction of a pathogen from outside the body?

Which term refers to infection caused by introduction of a pathogen from outside the body?

• A. Endogenous infection
• B. Subclinical case
• C. Carrier
• D. Exogenous infection

Answer: (D)

Exogenous infection occurs when a pathogen is introduced from outside the body. Infections like this come from external sources—breathing in droplets, eating or drinking contaminated material, touching contaminated surfaces, or receiving pathogens via invasive procedures or medical instruments. This differs from endogenous infection, which starts from microbes that are already part of the body's normal flora and become pathogenic after disruption. A subclinical case is an infection that doesn’t produce noticeable symptoms, and a carrier harbors the pathogen and can spread it without necessarily showing illness. Since the question describes infection caused by introduction from outside, the term exogenous infection best fits.

Exogenous infection occurs when a pathogen is introduced from outside the body. Infections like this come from external sources—breathing in droplets, eating or drinking contaminated material, touching contaminated surfaces, or receiving pathogens via invasive procedures or medical instruments. This differs from endogenous infection, which starts from microbes that are already part of the body's normal flora and become pathogenic after disruption. A subclinical case is an infection that doesn’t produce noticeable symptoms, and a carrier harbors the pathogen and can spread it without necessarily showing illness. Since the question describes infection caused by introduction from outside, the term exogenous infection best fits.