Cryptococcosis is a major cause of illness and death among persons infected with human immunodeficiency virus (HIV). Its management must include both initial and maintenance treatment. Although most authorities favor an initial period of
therapy with
amphotericin B for acute
cryptococcosis, the
triazoles play a role in both the management of
acute disease and subsequent maintenance
therapy.
AIDS surveillance data collected by the Centers for Disease Control and Prevention document the occurrence of
cryptococcosis in more than 17,000 (6.2%) of adults with
AIDS in the United States, although this figure is known to be an underestimate. The risk of
cryptococcosis among HIV-infected persons is highest at CD4+ lymphocyte counts of < 100/microL. Although
cryptococcosis is especially frequent among
AIDS patients who are black, male, or injection drug users, the explanations for these patterns remain unclear. Whether geographic differences in rates of
cryptococcosis result from variations in the environmental distribution of Cryptococcus neoformans as well as in the distribution of
HIV infection is also unclear. Although exposure to pigeon feces is the best known of the putative exposure-related risk factors, proof is lacking that avian excreta are the primary environmental source of the organism in most cases of
cryptococcosis. Prophylaxis with
triazoles can prevent
cryptococcosis and may be considered for adults and adolescents with CD4+ counts of < 50/microL. However, it is uncertain whether prophylaxis will affect survival, be cost-effective, or have an adverse impact on the susceptibility of a variety of fungi to antifungal drugs.
Vaccines and
monoclonal antibodies designed to prevent or modify
cryptococcosis in HIV-infected persons are in the experimental stage.