title: [Epidemiology of varicella in spain pre-and post-vaccination periods].
abstract: BACKGROUND
  Varicella virus can cause two different diseases: chickenpox and herpes zoster. In 2005 varicella vaccine has been introduced in the Spanish national vaccination schedule for 10-14 years old non-immune people, in order to reduce the severity of the disease. In 2007 a new surveillance protocol with aggregate data for chickenpox and herpes zoster was approved in order to detect any change in age distribution, severity and complications of the chickenpox and herpes zoster cases. The aim of this study is to know the burden of diseases (in the last ten years).
  
  
  METHODS
  Number of cases, hospitalization and incidence for chickenpox and herpes zoster were study for two periods 1997-2003 and 2005-2007. Analysis for 1996-2007 fatal cases was done too. We decided to remove year 2004 because the extremely high chickenpox incidence registered.
  
  
  METHODS
  RENAVE (Spanish Surveillance Network), Spanish hospital surveillance system (CMBD), and mortality registries.
  
  
  RESULTS
  Chickenpox incidence decreased since 2005, but an increasing trend was detected in hospitalisation with an average of 1,311 hospitalizations every year. For the 32%-36% of hospitalized cases, the main diagnosis was not chickenpox. 4-14 deaths per year have been detected; 80% of them were older than 14 years. Annual rate of herpes zoster hospitalization was 2.5 per 100,000 inhabitants, similar in both sexes. Case fatality rate per year was 0.31 per million inhabitants. No significant changes were detected in age and sex in complicated cases between the two periods. 88% of chickenpox cases were younger than 15 years old and 64% of herpes zoster older than 50 years in 2007.
  
  
  CONCLUSIONS
  Chickenpox has been decreasing during 2005-2007 in Spain. The impact of vaccination is difficult to asses, because of a peak registered in 2004 but also because the lack of vaccination coverage information for this period and the case-data information is available only for the last year.
authors.affiliation: Centro Nacional de Epidemiología, Instituto de Salud Carlos III, Madrid, España. sabela@isciii.es
authors.forename: Isabel
authors.initials: I
authors.lastname: Peña-Rey
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Martínez de Aragón
authors.forename: Ana
authors.initials: A
authors.lastname: Villaverde Hueso
authors.forename: Monserrat
authors.initials: M
authors.lastname: Terres Arellano
authors.forename: Enrique
authors.initials: E
authors.lastname: Alcalde Cabero
authors.forename: Berta
authors.initials: B
authors.lastname: Suárez Rodríguez
mesh_terms: D000293:Adolescent; D000328:Adult; D002644:Chickenpox / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control*; D019433:Chickenpox Vaccine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D019433:Chickenpox Vaccine