Pneumocystis carinii pneumonia.

Pneumocystis carinii (PCP) pneumonia is the most common pulmonary infection associated with the acquired immunodeficiency syndrome (AIDS). Patients at risk for PCP have defects in T lymphocyte function and include cancer and transplant patients who are on immune suppressing agents and corticosteroids. In West Virginia, PCP accounted for 53 percent of pulmonary infections in 144 cases of AIDS from 1984 to May 1990. Nationally, at least 100,000 cases of PCP are projected for the early part of this decade. Patients with PCP may present with non-specific symptoms. The chest X-ray frequently shows diffuse bilateral infiltrates but may have atypical features. Definitive diagnosis should be established using sputum staining and various bronchoscopic techniques. Trimethoprimsulfamethoxazole and IV pentamidine are the most efficacious agents for treatment, and monthly aerosolized pentamidine is recommended for prophylaxis. Further basic science and clinical research on the biology of the P. carinii and its response to treatment strategies in HIV and non-HIV related infections is urgently needed.