Epidemiology of Herpes Zoster Infection among Patients Treated in Primary Care Centres in the Valencian Community (Spain)

BACKGROUND: There is little available data regarding the epidemiology of herpes zoster (HZ) in Spain. This study's main goal was to estimate the annual incidence of HZ in the Autonomous Community of Valencia. METHODS: From December 1(st )2006 to December 1(st )2007, a prospective study was carried out in 24 primary health care centres that together provide care for a population of 36,030 persons aged >14 years. We included all adult patients with a clinical diagnosis of HZ who were seen at these centres during the one-year study period. Demographic (i.e., age, gender, and area of residence) and clinical data were also collected from these patients. RESULTS: A total of 146 cases of HZ were identified during the study period. The annual incidence of HZ was 4.1/1,000 individuals >14 years of age (95% confidence interval [CI]: 3.4-4.7). Cases of HZ were predominantly unilateral and most commonly affected women and people living in rural areas. The most frequently reported symptoms were pain, dysesthesia and itching. A total of 46% of patients also had underlying illnesses (e.g., chronic diseases and/or malignancy) and 24% of patients experienced complications, which were mostly ocular in nature. A total of 91% of patients were treated with antiviral drugs. The median time from symptoms onset to diagnosis was 6.3 days (range: 2.0-8.3). CONCLUSIONS: HZ is a common illness in our region (especially in the older population) that causes a significant clinical burden on primary care providers.