Fig. 1From: Varicella seroprevalence in healthcare workers in a tertiary hospital: an audit of cross-sectional dataCrude seroprevalence by year of screening with 95 % confidence intervals. We calculated and plotted crude seroprevalence figures for each year of health screening. Error bars were computed using binomial 95 % confidence intervals for the proportions of employees found to be immune on varicella serologyBack to article page