Methods: A retrospective chart review at 3 tertiary care pediatric hospitals serving the population of greater Tel-Aviv area. The medical records of all children aged 0 to 18 years hospitalized with the diagnosis Varicella between January 2004 to 31st December,2012 were retrieved for analysis.
Results: In the years 2004-2008 (the years before the vaccination program) the rate of hospitalization due to varicella was 38.9 cases per 10,000 children hospitalized, compared with 14.5 cases per 10,000 in 2009-2012 (the years after the vaccination program), i.e. 63% overall reduction in the rate of hospitalizations due to varicella (P <0.01). In 2004-2008, 86% of children hospitalized were 1-6 years old, 7.8% over the age of 6 years and 6.2% under the age of 1 year. In 2009-2012 only 55.8% of children were 1-6 years old, with 28.9% over the age of 6 years and 14.3% under the age of 1 year, a difference that was statistically significant. 11.7% of children were immune compromised that were not vaccinated before, with a higher percent of immune compromised children among those hospitalized in 2009-2012 (18.4% vs. 9.7%, p<0.05). Only 3.9% of children were vaccinated prior hospitalization. The most common complication was soft tissue infection (60% of all children), without statistically significant difference between the periods. The most prevalent pathogens were, Group A β-hemolytic streptococcus (53%) and Staphylococcus aureus(32%).
Conclusion: The study confirms that varicella vaccination has the ability to dramatically decrease varicella burden, both directly and possibly through herd immunity. In the 4 years after the introduction of varicella vaccine, a major reduction in varicella hospitalization was observed. For evaluation of the epidemiologic impact of the 2-dose policy on varicella and Herpes Zoster, nationally representative data are needed to more accurately monitor the impact of the varicella vaccination program.
G. Paret, None
A. Bar Yochai, None
O. Halutz, None