opportunistic condition

opportunistic condition A condition that occurs especially or exclusively in persons with weak immune systems due, for example, to AIDS, cancer, or immunosuppressive drugs, such as corticosteroids or chemotherapy. An opportunistic condition may be an infection, such as toxoplasmosis or cytomegalovirus (CMV), or a tumor, such as Kaposi sarcoma in AIDS. See also opportunistic infection; opportunistic microorganism.