ABSTRACT
Modern antiretroviral therapy (ART) has resulted in a dramatic reduction in the incidence of severe and life-threatening opportunistic infections associated with HIV infection. Such disorders as Pneumocystis carinii pneumonia (PCP), Toxoplasma encephalitis, and cryptococcal meningitis, which cost many lives, and Cytomegalovirus (CMV) retinitis, a frequent cause of blindness, during the first 15 years of the AIDS epidemic have become unusual among patients receiving effective ART. In fact, many such patients have experienced such significant increases in CD4+ lymphocyte counts that preventive therapy for such previously common disorders as CMV retinitis, PCP, and toxoplasmosis infection has been withdrawn. Nonetheless, many patients continue to suffer and die from HIV-related opportunistic infections, particularly in the resource-limited settings that exist in most of the areas of the world most impacted by HIV/AIDS. There are several reasons for this. Many individuals enter care late and present with opportunistic infections as their initial manifestation of AIDS before ART is instituted. In addition, many have failed multiple antiretroviral regimens and have not seen significant immune reconstitution. Finally, prophylaxis directed against some opportunistic pathogens is not universally prescribed and taken.
