title: Seroprevalence of pandemic 2009 (H1N1) influenza A virus among schoolchildren and their parents in Tokyo, Japan.
abstract: Since its emergence, the 2009 pandemic H1N1 virus has spread rapidly throughout the world. Previously, we reported that most individuals born after 1920 do not have cross-reactive virus-neutralizing antibodies against pandemic (H1N1) 2009 virus, indicating that they were immunologically naïve to the pandemic virus prior to its emergence. This finding provided us with an excellent opportunity for a seroepidemiological investigation of the transmission mode of the pandemic virus in the community. To gain insight into its transmission within communities, we performed a serosurvey for pandemic virus infection with schoolchildren at an elementary school in Tokyo, Japan, and their parents. We observed a high prevalence of neutralizing antibodies to the pandemic virus in the children at this school, although the percentage of children positive for the neutralizing antibodies varied among classrooms. While a much lower prevalence was observed among parents, seropositivity of the parents correlated with that of their schoolchildren. Moreover, many adults appeared to have experienced asymptomatic infection with the pandemic virus. These data suggest that the pandemic virus was readily transmitted among schoolchildren in elementary schools and that it was also transmitted from schoolchildren to their parents.
authors.affiliation: Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Iwatsuki-Horimoto
authors.forename: Taisuke
authors.initials: T
authors.lastname: Horimoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tamura
authors.forename: Maki
authors.initials: M
authors.lastname: Kiso
authors.forename: Eiryo
authors.initials: E
authors.lastname: Kawakami
authors.forename: Shuji
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ebihara
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Koibuchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujii
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takahashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimojima
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sakai-Tagawa
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Ito
authors.forename: Saori
authors.initials: S
authors.lastname: Sakabe
authors.forename: Ayaka
authors.initials: A
authors.lastname: Iwasa
authors.forename: Kei
authors.initials: K
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishii
authors.forename: Takeo
authors.initials: T
authors.lastname: Gorai
authors.forename: Koichiro
authors.initials: K
authors.lastname: Tsuji
authors.forename: Aikichi
authors.initials: A
authors.lastname: Iwamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
mesh_terms: D000328:Adult; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D058070:Asymptomatic Diseases; D002648:Child; D018562:Disease Transmission, Infectious; D005192:Family Health; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D008297:Male; D008875:Middle Aged; D010290:Parents; D016036:Seroepidemiologic Studies; D013334:Students; D014041:Tokyo / Q000453:epidemiology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral