The burden of disease of Herpes Zoster in Tuscany

Herpes zoster (HZ) is a disease caused by the reactivation of the latent α-herpes virus varicella zoster virus (VZV), for which, in Italy, a specific surveillance system does not exist, but around 200 000 cases are estimated each year. In older patients, who are at increased risk of developing HZ, symptoms are more severe and the chances to develop postherpetic neuralgia (PHN), the most severe complication, are substantially higher. A vaccine against HZ with demonstrated efficacy and an acceptable safety profile is now available and is recommended in Europe for adults >50 years.   In anticipation of the possible introduction of an immunization programme for the elderly in Tuscany, the burden of disease caused by HZ and its complications was assessed through a retrospective analysis of the hospital discharge records between 2002 and 2012, using the ICD-9-CM 053 code. In the period 2002-2012, 4475 hospital admissions were registered with annual means of 368 hospitalizations and 39 day-hospital admissions. Most of the hospitalizations (68%) involved subjects > 65 years; the mean length of stay was 9.5 days. Slightly more than half (51.2%) of total hospital admissions were complicated cases. The most frequent were neurological complications (24.2% of total admissions), followed by ophthalmic complications (16.5%). Cases with neurological complications were those with the higher average length of stay and higher average costs for case. This study confirmed the epidemiological impact of HZ and its complications and the positive impact on morbidity that the introduction of the HZ vaccination could have in older age groups.