Pneumocystosis is an infection of the lungs caused by the microorganism Pneumocystis carinii. Pneumocystosis is almost exclusively seen in individuals whose immune systems have been compromised by AIDS or chemotherapy. Pneumocystosis is usually a terminal event in AIDS patients.
Review Date 11/23/2021
Updated by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.