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Effect of mass immunization against influenza encephalopathy on mortality rates in children
Author(s) -
Ono Shigetoo,
Kudo Masanobu,
Aoki Kazuo,
Ezaki Fusako,
Misumi Junichi
Publication year - 2003
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/j.1442-200x.2003.01813.x
Subject(s) - medicine , encephalopathy , vaccination , pediatrics , fulminant , encephalitis , mortality rate , japanese encephalitis , immunization , immunology , virus , immune system
Background: Since the Japanese influenza vaccination program for school children was terminated in 1994, a steep rise has been noted in the number of young children reported with fulminant influenza and influenza associated with acute encephalopathy/encephalitis. The purpose of the present study was to interpret and clarify the effect of mass influenza vaccination on mortality of Japanese children, aged <19 years, with influenza and influenza‐associated acute encephalopathy/encephalitis.Methods: The authors examined the distribution of mortality rates of children in Japan aged <19 years with influenza during 1950−2000, influenza associated with central nervous system (CNS) signs in the period 1950−1978, and the estimated cases of influenza associated with acute encephalopathy/encephalitis in the period 1987−2000.Results: Total influenza mortality among children aged <19 years has increased since 1990, with children aged <4 years after 1994 being the worst affected. The mean values of mortality rates of influenza associated with central nervous system signs during 1963−1978 and the estimated mortality of children aged <9 years during 1979−1994 were significantly lower than in some years before 1962, and after 1995 ( P < 0.05). The annual mortality rates of influenza‐associated acute encephalopathy/encephalitis during 1995−2000 were significantly higher than the expected mortality of influenza associated with central nervous system signs in children aged <14 years ( P < 0.05).Conclusion: The results of the present study suggest that mass immunization of school‐aged children reduced the mortality rate from influenza‐associated acute encephalopathy/encephalitis in children less than 9 years of age.