The utility of serologic testing for varicella in an adolescent population.

The purpose of this study was to determine what proportion of adolescents without a history of varicella are seropositive, and if serologic testing of this adolescent subpopulation is cost-effective. We identified 122 patients with 'no' or 'unknown' histories of chicken pox from our adolescent clinic. Of these, 58 (48%) were found to be Varicella Zoster Virus (VZV) seropositive. Cost to the government for batched serologic testing of all unknowns was $682.65, while each adolescent vaccinated cost $59.60. Serologic testing prior to routine immunization of adolescents with unclear varicella histories saved $2774.15 (38% of routine immunization costs). In this population, serologic testing is more cost effective than routinely immunizing all unknowns.