Outbreak of varicella in a pediatric oncology unit.

Background: Varicella-zoster virus (VZV) infection is usually benign but immunocompromised patients are at great risk for visceral dissemination and fatal outcome. During a nationwide varicella outbreak, several of our patients contracted the disease. We undertook studies of the epidemiology and the efficacy of antiviral treatment and immunoprophylaxis.

Methods: During a 9-month period, 52 patients were exposed to cases of active varicella. Twenty-seven of these children were reexposed to active varicella > 1 month after their initial exposure. The exposure concerned 7 VZV waves of varying intimacy. In all cases, prophylaxis with intravenous immunoglobulin (IVIG), varicella zoster globulin (VZIG), or both was given. The spread of the disease was limited and only 6 patients (all immunosuppressed) developed varicella (7.6%). Three of 6 had been given IVIG and 3 VZIG + IVIG. All patients with varicella received acyclovir 30 mg/kg/day for 14 days. The disease was mild and all patients were ultimately cured.

Results: Our results show that prophylaxis was not 100% effective, but appearance to reduce the rate of spread. The differences in incidence among the regimens used were not significant.

Conclusions: For the moment, immunoprophylaxis and acyclovir administration appear to be quite satisfactory in managing immunocompromised children exposed to VZV. This may change with the wider use of the varicella vaccine.