A description usually applied to infection resulting from an organism that does not normally cause disease in a healthy individual. It is also used to describe widespread infection by an organism that usually causes local infection. The body’s defence mechanism can usually combat these organisms, but if it is impaired – as happens in AIDS/HIV or other immune de?ciencies– opportunistic infection, such as PNEUMONIA, may develop. Some viral and fungal infections behave in this way. Antimicrobial treatment is often e?ective, even though the weakness in the body’s defence mechanism cannot be recti?ed.
adj. denoting a disease that occurs when the patient’s immune system is impaired by, for example, an infection, another disease, or drugs. The infecting organism, which is also described as opportunistic, rarely causes the disease in healthy persons. Opportunistic infections, such as *Pneumocystis pneumonia and that caused by the MAI complex (see Mycobacterium), are common in patients with AIDS.
A variety of diseases which occur in some individuals who do not have healthy immune systems. These are microorganisms which do not usually cause diseases in a healthy individual. They are seen in AIDS patients and include Pneumocystis carinii pneumonia, massive or overwhelming herpes infections, atypical mycobacteria, toxoplasmosis or chronic or overwhelming candidiasis.... opportunistic infections
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