title: Effects of campaign for postpartum vaccination on seronegative rate against rubella among Japanese women.
abstract: BACKGROUND
  Japan experienced two rubella outbreaks in the past decade (2004 and 2012-2013), resulting in 10 and 20 infants with congenital rubella syndrome (CRS), respectively. This study was performed to determine whether the seronegative rate was lower in multiparous women than in primiparous women in Japan.
  
  
  METHODS
  Hemagglutination inhibition (HI) test results during pregnancy were analyzed retrospectively in 11048 primiparous and 9315 multiparous women who gave birth at six hospitals in northern Japan in the 5-year study period (January 2008 through December 2012). Women with HI titer <  1:8 were defined as susceptible to rubella.
  
  
  RESULTS
  The seronegative rate was significantly lower in multiparous than primiparous women aged 30 - 31 years (2.3% [22/967] vs. 4.5% [66/1454], P  =  0.0036), 36 - 37 years (3.4% [55/1601] vs. 5.7% [79/1389], P  =  0.0030), and overall women (3.8% [350/9315] aged 34.7  ±  5.2 vs. 5.4% [597/11048] for 33.2  ±  5.9, P  <  0.001). The susceptible fraction size did not differ largely according to hospital, ranging from 3.5% to 6.3%. Those for each year did not change markedly; 4.5% [150/3369], 5.2% [221/4268], 4.4% [195/4412], 4.6% [186/4056], and 4.6% [195/4258] for 2008, 2009, 2010, 2011, and 2012, respectively. Those for teenagers were consistently high: 22.7% [5/22], 20.7% [6/29], 20.6% [7/34], 13.0% [3/23], and 23.5% [4/17] for 2008, 2009, 2010, 2011, and 2012, respectively.
  
  
  CONCLUSIONS
  The seronegative rate was significantly lower in multiparous than primiparous women. However, Japanese rubella vaccination programs were insufficient to eliminate CRS.
authors.affiliation: Department of Obstetrics, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638, Japan. taka0197@med.hokudai.ac.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Junko
authors.initials: J
authors.lastname: Mochizuki
authors.forename: Masachi
authors.initials: M
authors.lastname: Hanaoka
authors.forename: Eriko
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Akihide
authors.initials: A
authors.lastname: Ohkuchi
authors.forename: Mika
authors.initials: M
authors.lastname: Ito
authors.forename: Takahiko
authors.initials: T
authors.lastname: Kubo
authors.forename: Akihito
authors.initials: A
authors.lastname: Nakai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saito
authors.forename: Nobuya
authors.initials: N
authors.lastname: Unno
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsubara
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D012189:Retrospective Studies; D012409:Rubella / Q000453:epidemiology / Q000517:prevention & control*; D012411:Rubella Vaccine / Q000008:administration & dosage* / Q000276:immunology; D014611:Vaccination / Q000379:methods / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D012411:Rubella Vaccine