An infection caused by one's own tissue or flora is called what?

• A. Nosocomial infection
• B. Autogenous infection
• C. Iatrogenic infection
• D. Opportunistic infection

Answer: (B)

Autogenous infection means the disease comes from the person’s own normal flora. These microorganisms live harmlessly in their usual niches, but if they are displaced into normally sterile tissues or the bloodstream, they can cause infection. This endogenous origin is what sets autogenous infections apart from infections acquired from the hospital (nosocomial), infections caused by medical procedures (iatrogenic), or infections by organisms that only cause disease when host defenses are reduced (opportunistic). For example, bacteria from the mouth or skin causing abscesses or wound infections after barrier disruption illustrate autogenous infection.