Which term describes when beneficial or harmless microorganisms in the body become pathogenic?

Which term describes when beneficial or harmless microorganisms in the body become pathogenic?

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

Answer: (D)

When organisms that normally live in the body become pathogenic, that is an endogenous infection. It means the source of the infection is inside the host—resident microbes that in a normal state are harmless or beneficial overgrow or invade when the environment changes, such as after a disruption of the immune system or disruption of anatomical barriers. This differs from infections acquired from outside the body (exogenous infection) or from someone who harbors a pathogen without disease (carrier), or from an infection that progresses with little or no symptoms (subclinical). The key idea is that the pathogen originates from within the body's own flora and becomes harmful under certain conditions, making endogenous infection the most accurate term.

When organisms that normally live in the body become pathogenic, that is an endogenous infection. It means the source of the infection is inside the host—resident microbes that in a normal state are harmless or beneficial overgrow or invade when the environment changes, such as after a disruption of the immune system or disruption of anatomical barriers. This differs from infections acquired from outside the body (exogenous infection) or from someone who harbors a pathogen without disease (carrier), or from an infection that progresses with little or no symptoms (subclinical). The key idea is that the pathogen originates from within the body's own flora and becomes harmful under certain conditions, making endogenous infection the most accurate term.