Nosocomial varicella. Part I: outbreak in oncology patients at a children's hospital.

Twenty cases of varicella occurred in patients or siblings of patients in a 41-day period in a children's hospital. Most cases were among oncology patients, with transmission occurring in both the inpatient and outpatient areas. One patient died after visceral dissemination of varicella. Neither pooled immunoglobulin nor zoster immune plasma was effective in preventing clinical varicella, although zoster immune plasma appeared to ameliorate the illness. Recommended control measures included strict isolation or discharge of infected patients, and respiratory isolation or discharge of exposed susceptibles. Although apparently too late to be effective in this outbreak, similar measures are warranted should nosocomial outbreaks of varicella occur elsewhere.