title: Prevalence of Helicobacter pylori infection with healthy subjects in Japan.
abstract: OBJECTIVE
  Only few large-scale epidemiological studies have examined the prevalence of Helicobacter pylori (H. pylori) infection in Japan. The aim of the present study was to estimate the prevalence and incidence of H. pylori infection in Japan in terms of gender, age and region.
  
  
  METHODS
  Serum anti-H. pylori antibody testing was included in workers' annual health checks conducted by T-company's health insurance association in 2008. The testing was continued for the next 5 years in 35-year-old subjects.
  
  
  RESULTS
  The total number of subjects was 21 144 (18 398 males and 2746 females). Stratified for age, there were 5016 subjects (male:female=4219:797) in their 30s, 8748 (7770:978) in their 40s, 5589 (4807:782) in their 50s, and 1769 (1584:185) in their 60s. The H. pylori seropositive rate (male:female) was 27.5% (27.5:27.7) overall, 18.0% (18.3:16.1) in subjects in their 30s, 22.9% (22.7:24.7) in those in their 40s, 37.4% (37.2:38.2) in those in their 50s, and 46.1% (45.7:49.2) in those in their 60s. The prevalence of H. pylori seropositivity increased as age increased; however, no significant differences were seen between genders or among regions (χ2 test). The numbers of 35-year-old subjects from 2008 to 2012 were 1072, 1107, 941, 1065, and 940, respectively. The corresponding H. pylori seropositive rates were 17.4, 17.4, 14.3, 13.3, and 14.0%, respectively.
  
  
  CONCLUSIONS
  The Japanese H. pylori infection rate had already declined to 27.5% in 2008, with subjects in the 35-70 age range. The prevalence of H. pylori infection is also decreasing gradually from 2008 to 2012.
authors.affiliation: Department of General Medicine & Primary Care, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Hirayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawai
authors.forename: Junji
authors.initials: J
authors.lastname: Otaki
authors.forename: Kohei
authors.initials: K
authors.lastname: Kawakami
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Harada
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D005756:Gastritis / Q000453:epidemiology* / Q000382:microbiology*; D016481:Helicobacter Infections; D016480:Helicobacter pylori; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors
keywords: Helicobacter pylori; anti-H.pylori antibody; infection rate