Respiratory infections in immunocompromised patients.

HIV disease has been dramatically reduced in the developed world by the introduction of highly active antiretroviral therapy, with implications that prophylactic therapy against opportunistic infections may be stopped; however, tuberculosis is an escalating problem in the HIV-infected and HIV-noninfected populations worldwide. Compliance with effective treatment regimens, especially through directly observed therapy, remains the cornerstone of tuberculosis control strategies. Although tuberculosis prophylaxis is of benefit for tuberculin skin reactors with HIV in the developed world, several reservations are voiced about this approach in resource-poor settings. Recent advances in technology, particularly in antigen-specific systems, have revolutionized the understanding of HIV immunology and helped to elucidate the mechanisms of pathogenesis in diseases such as cytomegalovirus. In bone marrow transplantation and solid-organ transplantation patients, quantitative polymerase chain reaction (PCR) to predict cytomegalovirus disease is an important advance, and patients who undergo bone marrow transplantation, CT scanning has proven useful in the diagnosis of pulmonary aspergillosis.