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opportunistic infection

n.

An infection by a microorganism that normally does not cause disease but becomes pathogenic when the body's immune system is impaired and unable to fight off infection, as in AIDS and certain other diseases.

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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Science definitions for opportunistic infection

opportunistic infection

[ŏp′ər-tōō-nĭs′tĭk]

An infection by a microorganism that normally does not cause disease but does so when lowered resistance to infection is caused by the impairment of the body's immune system.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Culture definitions for opportunistic infection

opportunistic infection

[(op-uhr-tooh-nis-tik)]

An infection caused by a microorganism that under normal conditions would not bring about disease. Opportunistic infections occur when the body's immune system is weakened by disease or malnutrition. (See AIDS.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.