ABSTRACT

Development of prophylactic, pre-emptive, and therapeutic strategies has reduced the morbidity and mortality of viral infections after HSCT. However, the future success of such strategies is threatened by the increasing emergence of antiviral-resistant virus strains.  In some cases, resistance is common enough to warrant changes in recommendations for prophylaxis (e.g  influenza in the 2008-9 season)².   In other cases (HSV, VZV, CMV, HBV), resistance has not yet altered the primary class of agent(s) utilized for prophylaxis or pre-emptive therapy at the majority of centers, but clinicians should have a heightened awareness of the possibility of antiviral resistance, and a low threshold to alter therapy in the setting of high viral loads, unusual clinical presentations, or refractoriness to standard therapy.  A detailed  overview of the scoop of this problem and strategies for managing patients with these difficult to treat infections is presented in this chapter.