title: Immunisation led to a major reduction in paediatric patients hospitalised because of the varicella infection in Israel.
abstract: OBJECTIVE
  The varicella-zoster virus causes infections that are often mild but can cause substantial morbidity and mortality in otherwise healthy children. We examined trends in varicella-related hospitalisations before and after the implementation of a national two-dose varicella vaccination programme in Israel in September 2008.
  
  
  METHODS
  This retrospective chart review, performed at three tertiary care paediatric hospitals in greater Tel Aviv, compared data from 2004 to 2008 and 2009 to 2012, before and after the varicella programme was launched. It included all children to the age of 18 who were hospitalised for conditions associated with the varicella infection.
  
  
  RESULTS
  After the vaccination programme was introduced, the number of children hospitalised for varicella fell by 63% (p < 0.5), from 38.9 to 14.5 per 10 000, and there was a 75% reduction in children aged one to six. During the same period, the percentage of hospitalised children who were immunocompromised rose from 9.7% to 18.4% (p < 0.05). The most common complications were soft-tissue infections (60%), and the most prevalent pathogens were Group A β-haemolytic streptococcus (53%) and Staphylococcus aureus (32%).
  
  
  CONCLUSIONS
  The introduction of a two-dose immunisation programme dramatically decreased the varicella burden in Israel, leading to a major reduction in hospitalisation admissions linked to the infection.
authors.affiliation: Department of Internal Medicine, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Elbaz
authors.affiliation: Department of Pediatric Intensive Care, Safra Children's Hospital, Tel Hashomer, Israel.
authors.forename: Gideon
authors.initials: G
authors.lastname: Paret
authors.affiliation: Department of Pediatrics, Assaf Harofeh Medical Centre, Zrifin, Israel.
authors.forename: Avihu Bar
authors.initials: AB
authors.lastname: Yohai
authors.affiliation: Microbiology Laboratory, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
authors.forename: Ora
authors.initials: O
authors.lastname: Halutz
authors.affiliation: Pediatric Infectious Disease Unit of Dana Children's Hospital, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
authors.forename: Galia
authors.initials: G
authors.lastname: Grisaru-Soen
mesh_terms: D002644:Chickenpox / Q000150:complications / Q000188:drug therapy / Q000517:prevention & control*; D019433:Chickenpox Vaccine; D002648:Child; D002675:Child, Preschool; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007557:Israel; D007902:Length of Stay; D012189:Retrospective Studies
chemical_list: D019433:Chickenpox Vaccine
keywords: Complications; Hospitalisation; Paediatric vaccination; Varicella infection