HIV in the older adult.

A 74-year old man, with a medical history of hypertension and marijuana abuse, presented with a non-productive cough, chills and progressive dyspnea on exertion for one week. On physical examination, his temperature was 100.6, oxygen saturation was 92% on room air. Lung examination revealed right posterior basal rales. Chest x-ray demonstrated a right lower lobe infiltrate with a small pleural effusion. He was started empirically on piperacillin/tazobactam for the likely diagnosis of communityacquired pneumonia. On the third day, oxygen saturation fell to 86% while on 2L of oxygen. Despite mild symptomatic improvement the day prior, a repeat chest x-ray now revealed diffuse bilateral haziness. At this point the patient was questioned further; he acknowledged a history of incarceration and multiple sexual partners. An HIV test result was positive, as were bronchial washings for pneumocystis; his CD4 count was 62. He was started on treatment for pneumocystis pneumonia.