Elsevier

Vaccine

Volume 25, Issue 43, 23 October 2007, Pages 7598-7604
Vaccine

Epidemiology and costs of herpes zoster: Background data to estimate the impact of vaccination

https://doi.org/10.1016/j.vaccine.2007.07.049Get rights and content

Abstract

In 2004, we conducted a study in Piemonte (Italy), in order to describe incidence, treatment, hospitalizations and costs of herpes zoster (HZ), in population over 14 years of age. Twenty-four regional general practitioners, with 26,394 patients >14 years in charge (0.71% of the regional population), reported prospectively all diagnosed HZ cases. In addition, all regional hospital discharge records were reviewed. Forty-six HZ cases treated at home were reported, accounting for a total incidence of 1.74 cases/1000 population >14 years per year. HZ rate standardized by age on regional population 14 years older is 1.59/1000.

The cost per observed home case was €136.06. The incidence of hospital admissions was 0.12/1000 inhabitants. The mean cost of hospitalized cases was €4082.59. These results contribute to depict the impact of HZ in the general population, and to provide background data for setting-up either mathematical models aimed to estimate the impact of vaccination on HZ, and the cost-benefit analyses of various preventive and therapeutic scenarios.

Introduction

Herpes zoster is a clinical manifestation caused by the activation of the varicella-zoster virus (VZV) which has remained latent in the ganglia and dorsal nerve roots after varicella infection. It is characterized by an eruption of groups of vesicles along the course of the nerve and may provoke chronic pain (postherpetic neuralgia (PHN)), especially in persons over 50 years of age. The estimated lifetime risk of developing herpes zoster in those exposed to varicella is between 10 and 30%, while the incidence and severity increase with advancing age and immunocompromising conditions [1], [2], [3], [4], [5].

The incidence of herpes zoster per 1000 person-years ranges between 1.2 and 4.8 [4]. Contrary to varicella, herpes zoster is not a notifiable disease in Italy, so that the only known figures are those derived from hospitalized cases, whence the absence of national surveillance data on the community incidence. A retrospective Italian study estimated the annual incidence in individuals ≥15 years of age to be 4.14 cases per 1000 population [6]. However, no Italian studies conducted to date have included epidemiologic and economic analyses that would permit estimation of the global impact of herpes zoster.

This study's objectives were to estimate the annual incidence of herpes zoster in individuals >14 years of age in the region of Piemonte and the hospitalizations rates for the disease, to describe the home care management of cases, and to calculate the cost of home care and hospital care based on the Italian National Health Service (NHS) reference costs.

Estimation of zoster incidence also constitutes an initial step in building mathematical models for calculating the impact of varicella vaccination interventions that take zoster reactivation into account. In fact, several mathematical models hypothesize that the widespread introduction of varicella immunization programs and consequent reduction in natural boosters could lead to an increased incidence in herpes zoster in adult and elderly individuals [7], [8], [9], [10], [11]. To this regard, analysis of HZ incidence in USA, where universal varicella vaccination was introduced in 1995, showed variable results, since an increasing incidence was reported in some studies, while others did not observe this finding [12], [13], [14], [15]. Moreover, in light of recent proposals to introduce a booster dose in adults 60 years of age or older to prevent zoster in the elderly, the description of case management could provide the basis for cost-benefit analyses comparing treatment and vaccination.

Section snippets

Materials and methods

We conducted an observational prospective study in Piemonte, a north-western region of Italy, with a population of 3,706,059 individuals 14 years old or older (people over 74 years of age represent 10.7% of this population).

Incidence

During the year of surveillance, 46 cases of herpes zoster were reported in subjects over 14 years of age, accounting for a total incidence of 1.74 cases/1000 population per year (95% CI: 1.28–2.32). The incidence rate by age according to the Poisson distribution is not increased in statistically significant way (Table 1); however, the comparison of the rates of age 15–64 vs. age >64 shows a statistical significant increase (0.85/1000 95% CI: 0.49–1.38 vs. 3.98/1000 95% CI: 2.69–5.68).

56.5% of

Discussion

According to our results, the estimated incidence of herpes zoster in adults in Piemonte is 1.59/1000 person years. This incidence is comparable to that reported in a recent British prospective study [16] involving GPs (1.85/1000), and approaches results of other studies from US (1.2–2.2/1000) [4], [22], UK (2.4–2.6/1000) [23], [24], Iceland (2/1000) [25] and Germany (2.3/1000) [26]. On the other hand, there are various other published European population-based studies, which show higher values

Acknowledgments

The authors would especially like to acknowledge the support of GPs Marilena Di Sario and Patrizia Piano.

This work was supported by a grant LOCALE 2006 (research found ex 60% 2005, University of Turin) and a grant PRIN 2005 (prot. MIUR 2005062795_003).

References (35)

  • M. Brisson et al.

    Epidemiology of varicella zoster virus infection in Canada and the United Kingdom

    Epidemiol Infect

    (2001)
  • A. Volpi et al.

    Current management of herpes zoster. The European view

    Am J Clin Dermatol

    (2005)
  • U. Di Luzio Paparatti et al.

    Herpes zoster and its complications in Italy: an observational survey

    J Infect

    (1999)
  • M. Brisson et al.

    Varicella vaccination: impact of vaccine efficacy on the epidemiology of VZV

    J Med Virol

    (2003)
  • A.O. Jumaan et al.

    Incidence of herpes zoster, before and after varicella-vaccination-associated decrease in the incidence of varicella, 1992–2002

    JID

    (2005)
  • W.K. Yih et al.

    The incidence of varicella and herpes zoster in Massachusetts as measured by the Behavioral Risk Factor Surveillance System (BRFSS) during a period of increasing varicella vaccine coverage, 1988–2003

    BMC Public Health

    (2005)
  • S. Goldman

    Varicella susceptibility and incidence of herpes zoster among children and adolescents in a community under active surveillance

    Vaccine

    (2003)
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