Treating Opportunistic Infections Among HIV-Infected Adults and Adolescents Effect of Antiretroviral Therapy on the Incidence and Management of OIs       Data from both randomized controlled trials and observational cohort studies document that antiretroviral therapy (ART) reduces the incidence of OIs and improves survival, independent of the use of antimicrobial prophylaxis, and reduces overall mortality among persons with HIV-1 infection . Potent ART does not replace the need for antimicrobial prophylaxis among patients with severe immune suppression. However, ART is the cornerstone of the overall strategy to reduce morbidity attributed to HIV-1--related infections and other HIV1--related processes. The clinical benefit of ART in reducing the risk for OIs over the short term has been best demonstrated for those with a CD4+ T lymphocyte count <200 cells/µL. Studies also support benefit in patients with CD4+ T lymphocyte counts >200 cells/µL, although the overall benefit of starting ART in this population is uncertain. Improvements in specific measures of immune function, including pathogen-specific immunity, have been well documented among patients who initiated ART at CD4+ T lymphocyte counts >200 cells/µL. Whether such measures correlate with clinical protection against infection or other HIV-1-related complications remains to be determined. In addition to preventing OIs, ART can lead to resolution or improvement of certain OIs, most notably for those where specific treatment is not available. Treatment of patients with ART in the setting of an OI also can result in an exuberant inflammatory reaction that might require the use of anti-inflammatory agents for clinical management. Finally, patients who receive potent ART can have atypical presentations of OIs either early after the initiation of ART or after prolonged treatment. Specific guidelines for the management of ART in the presence of acute OIs have not previously been developed. Two principal circumstances to consider include the initiation of ART in the setting of an acute OI, and the management of ART when an acute OI occurs in a patient who is already receiving ART. The management in each circumstance will vary depending on the degree of virologic and immunologic disease progression before initiation of ART and the virologic and immunologic benefit resulting from ART, the duration of HIV-1 disease before and since starting ART, and the potential for drug-drug interactions between the ART regimen and the treatment needed for the OI.