Onset and complications of varicella zoster reactivation in the autologous hematopoietic cell transplant population

Background. Varicella zoster virus (VZV) infections are a common complication in patients receiving autologous or allogeneic hematopoietic cell transplant (HCT). Recent guideline revisions suggest extending VZV prophylaxis to 1 year after autologous HCT. We retrospectively evaluated reactivation at our center, before implementation of extended acyclovir prophylaxis, to determine onset and outcome in the autologous HCT population. Methods. Inclusion criteria consisted of adult patients who received an autologous HCT with documentation for at least 1 year post transplant. Those excluded from review were patients who received acyclovir prophylaxis for >30 days post transplant or subsequently received an allogeneic transplant within 1 year. For patients in whom reactivation occurred, the severity of infection, the timing of onset, treatment of the reactivation, and any complications were recorded. Results. In the final analysis, 56 patients were assessed. Reactivation of zoster occurred in 16% of recipients with a median onset of 4.5 months post transplant. Complications that were observed include postherpetic neuralgia, severe pain, scarring, and motor weakness. Two patients required hospitalization for treatment, with 1 patient requiring 6 months of rehabilitation for motor weakness following the infection. Conclusions. Our study revealed a 16% incidence of VZV reactivation in our autologous HCT population. The onset of these occurrences ranged from 2 to 10 months post transplant, with significant VZV-associated complications. We consider VZV reactivation a serious concern in the autologous transplant setting, requiring extended prophylaxis.