Unusual infections and novel therapeutic strategies

The range of opportunistic pathogens identified as causing infection in immunocompromised patients continues to increase. Line-associated infections are a particular problem with a wide range of organisms, both bacterial and fungal, emerging as novel pathogens. Although documented gram-negative infections are declining, unusual environmental organisms are frequently encountered and problems with multiply resistant gram-positive organisms persist. Nonantimicrobial therapeutic approaches are increasingly being applied, with immunotherapy using monoclonal, polyclonal, or nonspecific immunoglobulin preparations as the favored option. Striking at the root cause of many serious infections, namely endotoxin and the mediators it stimulates, is increasingly the focus of immunotherapy in immunocompromised patients. In addition, there is increasing use of cytokine growth factors, designed to reduce neutropenia and lessen the risk for infection. Although most trials are prophylactic, larger-scale therapeutic studies are now in progress.