Opportunistic infections occur in people whose immune systems have been weakened by a disease, such as AIDS. An opportunistic infection may cause serious, even life-threatening, illness.

Opportunistic infections that are common in people who have AIDS include Pneumocystis pneumonia, tuberculosis, and toxoplasmosis. Treatment for opportunistic infections depends on the type of infection and the original disease.

By	Healthwise Staff
Primary Medical Reviewer	E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer	Peter Shalit, MD, PhD - Internal Medicine
Last Revised	April 8, 2010