Allogeneic-HCT recipients are at increased risk for varicella zoster virus (VZV) reactivation and associated complications. Prevalence, timing, and risk factors for severe HZ are uncertain in the era of acyclovir (ACV) prophylaxis. Identification of patients at risk for severe HZ can help target need for prolonged prophylaxis or vaccine administration. In this study, we characterized HZ infection requiring hospitalization in a cohort of allogeneic HCT recipients.
We performed a retrospective, single center, cohort study of all patients who underwent allogeneic HCT transplantation from 10/2006 – 12/2015. We defined severe HZ as infection requiring hospitalization or administration of IV antiviral medication. We defined HZ diagnosis by either microbiology confirmatory testing or classic dermatomal exam as agreed upon by two or more clinicians. We followed patients until 12/2017 for the development of HZ complications.
In a cohort of 2163 allogeneic HCT recipients, 23 patients (1.1%) developed severe HZ infection, 14 had microbiological confirmation and 9 diagnosed clinically. The median age was 37 years (range 18-63); 13/23 (56.5%) were male. Six patients had dermatomal HZ, five with disseminated cutaneous HZ, five with HZ ophthalmicus (one with retinal necrosis), three with VZV meningitis/encephalitis, two with VZV pneumonia, one with VZV viremia, and one with erythema multiforme with mucosal involvement. 90-day mortality from onset of diagnosis was 5/23 (21.7%). HZ reactivation occurred a median of 14 months after transplant (range 4-days pre-HCT to 80 months). Twelve patients (52.2%) were compliant on ACV prophylaxis at the time of reactivation, of which ten (83.3%) were on concurrent immunosuppression, including five (41.6%) on a steroid dose > 20 mg prednisone per day. In contrast, only 4/11 (36.4%) patients off ACV prophylaxis were on immunosuppression.
In the era of ACV prophylaxis, severe HZ reactivation was identified in 1.1% of HCT recipients. The majority of cases occurred < 24 months after transplant despite ACV use in many. HZ virus vaccination might be an additional means of prophylaxis in this vulnerable group.
S. Kanjilal, None
N. Issa, None
L. Baden, None
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