Overview of infection with the human immunodeficiency virus: infectious complications.

HIV is a retrovirus. Infection with HIV results in a progressive loss of immune function, primarily of the T-helper lymphocyte, although other arms of the immune system are secondarily affected. Patients who develop AIDS are amazingly susceptible to the development of opportunistic infections and neoplastic diseases. Common presentations include pneumonia, gastrointestinal infections, and central nervous system infections. Infections are usually due to reactivation of latent infections. These infections have a tendency to relapse and prolonged treatment appears to be necessary. HIV infection is occurring worldwide and medical personnel, especially pulmonary physicians, will be increasingly required to diagnose and treat infections occurring in these patients. The spread of HIV infection is already altering the epidemiology and clinical presentation of major infectious illnesses such as syphilis and tuberculosis.