ABSTRACT
Despite evidence-based prophylactic regimens and prompt use of neuroimaging, viral central nervous system (CNS) infections continue to cause significant morbidity and mortality in an increasing range of patients with altered immunity due to their conditions and/or treatments. This chapter reviews CNS viral infections in vulnerable patient cohorts. These cohorts comprise patients receiving conventional cytotoxic cancer treatments as well as the ever-increasing groups of patients receiving immunosuppressive or immunomodulatory therapies for neoplastic and non-neoplastic conditions, including hematopoietic cell and solid organ transplantation and rheumatologic disorders. Unlike other chapters in this volume, the approach here is organized by clinical approach and therefore not by pathogen but by disease-specific risks due to immune deficits and drugs received. The chapter provides guidance to choice of appropriate diagnostic and imaging investigation for rapid, accurate diagnosis and for confirmation of potential noninfectious conditions that can mimic CNS infection. HIV-associated infections are discussed elsewhere in this book.
