Epidemiology of human immunodeficiency virus-associated opportunistic infect-ions in the United States in the era of highly active antiretroviral therapy

The incidence of nearly all AIDS-defining opportunistic infections (OIs) de creased significantly in the United States during 1992-1998; decreases in t he most common OIs (Pneumocystis carinii pneumonia [PCP], esophageal candid iasis, and disseminated Mycobacterium avium complex [MAC] disease:) were mo re pronounced in 1996-1998, during which time highly active antiretroviral therapy (HAART) was introduced into medical care. Those OIs that continue t o occur do so at low CD4(+) T lymphocyte counts, and persons whose CD4(+) c ounts have increased in response to HAART are at low risk for OIs, a circum stance that suggests a high degree of immune reconstitution associated with HAART. PCP, the most common serious OI, continues to occur primarily in pe rsons not previously receiving medical care. The most profound effect on su rvival of patients with AIDS is conferred by HAART, but specific OI prevent ion measures (prophylaxis against PCP and MAC and vaccination against Strep tococcus pneumoniae) are associated with a survival benefit, even when they coincide with the administration of HAART. Continued monitoring of inciden ce trends and detection of new syndromes associated with HAART are importan t priorities in the HAART era.