![[Visit Client Website]](images/banner.gif)
Introduction: Varicella-Zoster Virus (VZV) infection is a relatively common cause of morbidity following autologous hematopoietic cell transplant (auto-HCT). Previous guidelines recommended antiviral prophylaxis against VZV only during the post HCT neutropenia period. The CDC in 2009 recommended extending VZV prophylaxis for 1 year post-transplantation.
Methods: We retrospectively analyzed rates of VZV infection following auto-HCT at our transplant center prior to and after the implementation of extended acyclovir prophylaxis in June 2008. We divided our study population into three different cohorts according to the length of VZV prophylaxis: (1) prophylaxis until neutrophil recovery to ≥500/uL (n=76), (2) prophylaxis for 6months (n=12) or (3) 12months (n=40) post auto-HCT. All patients received acyclovir 400 mg oral or iv twice daily or valacyclovir 500 mg oral daily. For patients in whom VZV infection occurred, data was collected on severity of infection, timing of onset, treatment of the reactivation and any associated complications.
Results: 128 patients undergoing auto-HCT between January 1, 2004 and January 31, 2010 were included in the study. Table 1 demonstrates baseline characteristics for the three cohorts. By Fisher's exact test, there was a significant difference in rates of VZV infection between the neutrophil recovery and 12months prophylaxis cohorts at 14% (n=11) and 2% (n=1) (P=0.03), respectively. VZV infection rate in the 6months prophylaxis group was 16% (n=2), but did not reach statistical significance due to small numbers. Median time to the onset of VZV infection was 4 months (1-10 months) in the neutrophil recovery group, whereas only 1 event occurred in the 12 month prophylaxis group at 19-months post-transplant. Complications observed with VZV infections include post-herpetic neuralgia (n=5), severe pain (n=3), scarring (n=1), and motor weakness (n=1); 2 patients required hospitalization and 3 patients developed disseminated zoster.
Conclusions: Our limited retrospective analysis suggests a significant reduction in rates of post auto-HCT rates of VZV infection with extended 12month antiviral prophylaxis. VZV infection is a significant complication post auto-HCT, and extended prophylaxis appears to be safe and effective in this setting.
