Helicobacter pylori infection in Japan

Citation metadata

Publisher: Expert Reviews Ltd.
Document Type: Report
Length: 4,869 words
Lexile Measure: 1440L

Document controls

Main content

Article Preview :

Author(s): Seiji Shiota 1 2 , Kazunari Murakawi 2 , Rumiko Suzuki 1 , Toshio Fujioka 2 , Yoshio Yamaoka [*] 3

Keywords

:

guideline; Helicobacter pylori; Japan; management; resistance; treatment

Epidemiology

Helicobacter pylori infection is now regarded as a high risk factor for severe gastritis-associated diseases, including peptic ulcer and gastric cancer [1] . The infection persists for a long period of time in most infected patients, but only a small fraction of these patients develop associated diseases [2] . The transmission mechanism of H. pylori is not fully understood, but human-to-human spread through the oral-oral or fecal-oral routes is thought to be the most plausible [3] . Studies have demonstrated the presence of H. pylori in drinking water and indicated the influence of poor living conditions and sanitation on H. pylori infection, supporting the oral-fecal route of spread. In Japan, a rapid change occurred in the sanitary conditions and standard of living after World War II; clean public water systems were introduced in Japan in the 1950s. H. pylori infection rates gradually increased with age until 39 years of age, after which a high plateau was reached (i.e., more than 70%) at ages of 40 years or above, according to a report published in 1992 (Figure 1) [4] . These rates are higher among individuals born before 1950 and lower for those born thereafter. Our report conducted from 2002 to 2006 also showed that the prevalence of H. pylori infection increased with age [5] . We examined the H. pylori infection rate for 5550 patients in our hospital from 2007 to 2011. Compared with previous reports, a decrease in the H. pylori infection rate was observed for each age group (Figure 1). Importantly, the H. pylori infection rate was decreased even after the rates shifted. Several antibiotics are used for other common infections in Japan, which may contribute to the decreased H. pylori infection rate. However, the H. pylori infection rate did not change among those below 40 years of age between 2002 and 2006, and 2007 and 2011 in our study, although the reason for this remains unclear. This suggests that H. pylori infection must be considered even in young patients. Moreover, reinfection of H. pylori should be considered even after successful eradication therapy. A recent study found the reinfection rate after successful eradication therapy in adults to be 0.22% per year [6] . Recrudescence or reinfection can often occur at during the first year of follow-up. Therefore, the status of H. pylori should be examined at least at the first-year follow-up. Overall, the H. pylori infection rate in Japan will likely continue to fall due to the improvement of sanitary conditions and the use of antibiotics. This suggests that the prevalence of H. pylori -related diseases will also decrease in the future. The prevalence of peptic ulcer and gastric cancer significantly decreased in 2005 compared with the prevalence observed in 1988 in Japan [7] .

Virulence factors of H. pylori in Japan

In addition to host factors and diet, virulence factors of H. pylori , such as cagA, vacA, oipA , babA,...

Source Citation

Source Citation   

Gale Document Number: GALE|A312892151