507 SUSCEPTIBILITY TO VARICELLA ZOSTER VIRUS (VZV) AMONG ADULTS AT HIGH RISK FOR EXPOSURE

Abstract

Hospital personnel, especially those who work with children or the immunocompromised, are at increased risk for exposure to VZV. For example, in a 21 month period we prospectively recorded 16 uncontrolled introductions of VZV into our hospital. These resulted in exposure of 273 patients and 426 hospital personnel. 29 exposed employees (7%) were uncertain of their VZV immune status and of these 13 were found to be serologically VZV susceptible. Because the susceptible adult represents both a risk to the hospital and to himself, we prospectively defined the VZV immune status of 2501 (of 2694) Children's Hospital employees. 2051 employees (82%) reported a prior history of varicella or herpes zoster which was accepted as evidence of immunity. Sera from 291 of 446 employees with uncertain prior VZV infection were tested by ELISA and/or FAMA for serologic evidence of VZV immunity. 79 sero susceptible individuals were identified and during the subsequent 10 months, five of these adults acquired varicella from sources outside of the hospital. Varicella also occurred in one individual who had a negative history but did not submit blood for serology. Adults at high risk for exposure should be screened for immunity to VZV by history, and if uncertain, by serologic testing. Such individuals who are found to be susceptible should be aware of the potential to both acquire and spread VZV. Susceptible adults at high risk for VZV exposure represent potential candidates for VZV immunization.