Definitions for "Opportunistic infections"
Infections (rarely seen in healthy people) that that occur when a person's immune system is weakened due to HIV, cancer, or drugs that suppress the body's immune response
Infection in an immune compromised person caused by an organism that does not usually cause disease in healthy people. Many of these organisms are widely carried in the population in a latent state, and only cause disease when given the opportunity of a damaged/compromised immune system.
Infections and illnesses that happen when a person's immune system is weakened by HIV infection. These illnesses are not common in people with functioning immune systems. People with advanced HIV disease or an AIDS diagnosis can have infections of the lungs, brain, eyes and other organs. Opportunistic infections that can occur in people with AIDS include Pneumocystis carinii pneumonia (PCP), candidiasis (yeast infections or thrush), cancers and Mycobacterium avium complex (MAC). (For a complete list of AIDS-defining illnesses, please visit
A pathological deficiency in the oxygen-carrying component of the blood, measured in unit volume concentrations of hemoglobin, red blood cell volume, or red blood cell number.