Do the health-care workers gain protection against herpes zoster infection? A 6-year population-based study in Taiwan.

Varicella zoster virus (VZV) causes varicella, and may reactivate to cause herpes zoster later in the life of the host. It has been previously observed that exposure to VZV may boost the host's latent immunity. Health-care workers who are frequently exposed to ill patients ought to receive a protective effect. We investigated the incidence of herpes zoster among health-care workers and the general population in Taiwan to see whether such a protective effect exists among health-care workers against herpes zoster. This nationwide population-based retrospective cohort study was based on data obtained from the Taiwan National Health Insurance Database. In total, 7744 health-care workers, including 168 dermatologists and pediatricians, and 695 188 general adults were recruited for the study. Health-care workers in the age groups 20-29, 30-39 and 40-49 years were found to have a significant higher herpes zoster incidence compared to the general adults (P < 0.001, 0.011 and <0.001, respectively). Both logistic regression and Cox regression showed that dermatologists, pediatricians, and other medical professionals have a higher herpes zoster incidence than the general population (odds ratio [OR] = 1.36, 95% confidence interval [95% CI] = 0.63-2.90, hazards ratio [HR] = 1.35, 95% CI = 0.64-2.82 in dermatologist and pediatrician groups, and OR = 1.39, 95% CI = 1.23-1.58, HR = 1.38, 95% CI = 1.22-1.56 in other medical professionals). The incidence of herpes zoster is higher among health-care workers and it can be clearly concluded that no protective effect against herpes zoster exists for health-care workers in Taiwan.