Infections in patients with cancer undergoing chemotherapy: aetiology, prevention, and treatment.

Patients with cancer who are undergoing chemotherapy are highly susceptible, especially if neutropenic, to almost any type of bacterial or fungal infection. These infections cause substantial morbidity and mortality. Prophylactic use of antibiotics should be avoided, however, since this practice is associated with a risk of emergence of resistant bacteria and it does not lower the risk of death. However, chemoprophylaxis has a role for candidal fungal infections. Because infection in a neutropenic host can be rapidly fatal if not treated, the empirical administration of broad-spectrum intravenous antibiotics is generally indicated for these patients, and the local frequencies, susceptibility, and resistance patterns of various pathogens must be taken into account. Once therapy has been initiated, changes in antibiotic regimens during the first 5 days are useless unless the patient's clinical condition deteriorates substantially. The treatment of invasive fungal infections is particularly difficult. Many unsolved questions remain, and studies are proposed here that may shed light on these issues.