Endogenous infections are caused by what?

Endogenous infections are caused by what?

• A. Pathogens introduced from outside the body
• B. Pathogens transmitted by vectors
• C. Beneficial or harmless microorganisms becoming pathogenic
• D. Infections acquired in the hospital

Answer: (C)

Endogenous infections come from microorganisms that normally live on or inside the body as part of the usual microbiota. These organisms can cause disease when the local balance is disrupted or the immune system is weakened, allowing them to become pathogenic. That makes the idea of normal residents turning pathogenic the best fit. In contrast, infections caused by pathogens from outside the body, those transmitted by vectors, or infections acquired in a hospital setting are not based on the body's own usual flora turning pathogenic, so they don’t describe endogenous infections. An example is an overgrowth of a normally harmless resident after antibiotics, such as Candida causing infection when competing bacteria are suppressed.

Endogenous infections come from microorganisms that normally live on or inside the body as part of the usual microbiota. These organisms can cause disease when the local balance is disrupted or the immune system is weakened, allowing them to become pathogenic. That makes the idea of normal residents turning pathogenic the best fit.

In contrast, infections caused by pathogens from outside the body, those transmitted by vectors, or infections acquired in a hospital setting are not based on the body's own usual flora turning pathogenic, so they don’t describe endogenous infections. An example is an overgrowth of a normally harmless resident after antibiotics, such as Candida causing infection when competing bacteria are suppressed.