title: Systematic review of incidence and complications of herpes zoster: towards a global perspective.
abstract: OBJECTIVE
  The objective of this study was to characterise the incidence rates of herpes zoster (HZ), also known as shingles, and risk of complications across the world.
  
  
  METHODS
  We systematically reviewed studies examining the incidence rates of HZ, temporal trends of HZ, the risk of complications including postherpetic neuralgia (PHN) and HZ-associated hospitalisation and mortality rates in the general population. The literature search was conducted using PubMed, EMBASE and the WHO library up to December 2013.
  
  
  RESULTS
  We included 130 studies conducted in 26 countries. The incidence rate of HZ ranged between 3 and 5/1000 person-years in North America, Europe and Asia-Pacific, based on studies using prospective surveillance, electronic medical record data or administrative data with medical record review. A temporal increase in the incidence of HZ was reported in the past several decades across seven countries, often occurring before the introduction of varicella vaccination programmes. The risk of developing PHN varied from 5% to more than 30%, depending on the type of study design, age distribution of study populations and definition. More than 30% of patients with PHN experienced persistent pain for more than 1 year. The risk of recurrence of HZ ranged from 1% to 6%, with long-term follow-up studies showing higher risk (5-6%). Hospitalisation rates ranged from 2 to 25/100 000 person-years, with higher rates among elderly populations.
  
  
  CONCLUSIONS
  HZ is a significant global health burden that is expected to increase as the population ages. Future research with rigorous methods is important.
authors.affiliation: Global Health Outcomes, Merck & Co., Inc., West Point, Pennsylvania, USA.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kawai
authors.affiliation: School of Public Health, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA.
authors.forename: Berhanu G
authors.initials: BG
authors.lastname: Gebremeskel
authors.affiliation: Global Health Outcomes, Merck & Co., Inc., West Point, Pennsylvania, USA.
authors.forename: Camilo J
authors.initials: CJ
authors.lastname: Acosta
mesh_terms: D014943:Global Health; D006562:Herpes Zoster / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D012307:Risk Factors
keywords: EPIDEMIOLOGY; VIROLOGY