Opportunistic infections of the central nervous system in the transplant patient

Therapeutic advances in transplantation medicine have resulted in ever expanding patient populations that receive organ or stem cell transplantation. Modern potent immunomodulatory therapies have resulted in improvements in allograft and patient survival, but, consequently, as a result of the immunosuppressive state, transplant recipients are highly vulnerable to infection, including those that affect the central nervous system (CNS). CNS infections present a diagnostic and therapeutic challenge for clinicians involved in the care of the transplant patient, with a propensity to result in profound morbidity and often high mortality in this patient population. Here, we review major opportunistic pathogens of the CNS seen in transplant patients, highlighting distinguishing epidemiologic and clinical features.