Patients with neoplastic disease and suspected infection come to the physician with the following main factors to be considered in their evaluation: (1) their epidemiologic background and (2) their known and unrecognized immune defect or defects including history of recurrent infections and familial/genetic predisposition to certain infections (Table 85.1). The febrile cancer patient raises the question whether the fever is caused by the neoplasm. After evaluation, the next question is whether to treat empirically. In this chapter, an approach to these patients is outlined, stressing the individuality of each patient along with the complexity of the evaluation.

EPIDEMIOLOGY

People may be exposed to a variety of organisms through travel, work, habits, or hobbies; in the home; or in other hospitals, outpatient clinics, and infusion centers. The right questions must be asked about their background. A person with children at home is likely to be exposed to a number of infectious agents such as influenza, parainfluenza, respiratory syncytial virus, varicella-zoster virus (VZV), human herpesvirus 6 (HHV6), and cytomegalovirus (CMV). Hospitals are a rich source of antibiotic-resistant microorganisms, including multidrug-resistant Staphylococcus aureus (MRSA), vancomycin-resistant and/or vancomycin- tolerant Enterococcus species, multidrugresistant Pseudomonas, Stenotrophomonas, and extended-spectrum β-lactamase-producing Enterobacteriaceae such as Escherichia coli and Klebsiella species. It is important to know where an individual has been hospitalized and what resistance patterns are known to inhabit that hospital. Furthermore, as the spectrum of infection continues to change, it is imperative to follow these trends; just as community-acquired MRSA has recently surpassed hospitalization as a more common source of these resistant bacteria, other traditional risk factors for acquiring an infection may also change.