Introduction of an examination and treatment for Helicobacter pylori infection in high school health screening

Parental Knowledge and Attitudes Towards Helicobacter Pylori Screening in Adolescents: A School-Based Questionnaire Study Among Guardians of Junior High School Students in Yokosuka City, Japan

PURPOSE

Helicobacter pylori (HP) infection, a risk factor for gastric cancer, is prevalent in Japan. Consequently, some municipalities across Japan are implementing HP screening and treatment programs for adolescents. However, little is known about parents' attitudes and awareness regarding HP screening for their children. This study aimed to elucidate parental perspectives on HP screening for their children and identify the factors influencing these attitudes.

METHODS

This study focused on the parents of first-year junior high school students in Yokosuka City, Kanagawa Prefecture, where an HP screening and treatment program had been implemented for adolescents. The survey questionnaire was distributed among parents in all 23 public junior high schools in Yokosuka City.

RESULTS

Among the 618 respondents, 86.4% supported HP screening for their children. Regression analysis identified sufficient knowledge about HP (adjusted odds ratio (aOR) = 5.80; 95% confidence interval (CI), 2.10-16.03) and being in their 40s (aOR = 2.25; 95% CI, 1.35-3.77) as significant factors influencing supportive attitudes. For parents favoring the screening, common reasons included perceiving it as a promising opportunity (53.2%) and considering the test necessary (44.0%). In contrast, those who opposed screening frequently cited it as unnecessary (66.7%) or believed that their children did not have HP.

CONCLUSIONS

A significant proportion of parents in Yokosuka City, Japan, demonstrated a good understanding of HP and expressed a high level of interest in HP screening for their children. Further investigation of parents' attitudes is essential for the effective implementation of adolescent HP screening programs.

Efficacy and safety of vonoprazan-based regimen for Helicobacter pylori eradication therapy in Japanese adolescents: a prospective multicenter study

BACKGROUND

Vonoprazan (VPZ)-based regimen for Helicobacter pylori (H. pylori) is safe and more efficacious than the proton pump inhibitor-based regimen mainly in adults. This study aimed to evaluate the efficacy and safety of a VPZ-based regimen for H. pylori eradication therapy in adolescents.

METHODS

An H. pylori screening and treatment longitudinal project for third-year junior high school students in Saga Prefecture began in 2016. Students who tested positive for both urine and stool tests received a VPZ-based regimen. On the checklist, students were asked for diarrhea, fever, abdominal pain, nausea, vomiting, urticaria, dysgeusia, or bloody stool occurrence during the therapy.

RESULTS

The longitudinal project for H. pylori screening and treatment among third-grade students in Saga Prefecture targeted 41,115 students from 2017 to 2021 and 836 as positive. Of the 645 students, 542 (84.0% in per protocol [PP] analysis and 73.6% in intention-to-treat [ITT] analysis) were successful in primary eradication therapy. The secondary eradication therapy was successful in 79 (96.3% in PP analysis and 76.7% in ITT analysis) of 82 students. In the primary eradication therapy, abdominal pain occurred in 164 (27.9%), diarrhea in 217 (36.9%), nausea or vomiting in 7 (1.2%), and urticaria in 13 (2.2%) students. In the secondary eradication therapy, abdominal pain occurred in 12 (19.4%) and diarrhea in 17 (27.4%) students. The eradication therapy of 5 students was interrupted due to adverse events only by primary eradication therapy.

CONCLUSIONS

VPZ-based regimen for H. pylori was efficacious and safe for adolescents, as in adults, for both primary and secondary eradication therapies.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Clinical Evaluation of a Novel Stool Antigen Test Using Bioluminescent Enzyme Immunoassay for Detecting Helicobacter pylori

BACKGROUND

BLEIA ™ "EIKEN" Helicobacter pylori antigen (B[EIA]) is based on the bioluminescent enzyme immunoassay (BLEIA) method that was newly developed with high sensitivity in detecting Helicobacter pylori (H. pylori) antigen in feces.

METHODS

In the project for H. pylori screening and treatment in Saga Prefecture in 2019, 141 students received the stool H. pylori antigen test as a secondary test. For 141 students, a comparative test was conducted between B (EIA) and extracorporeal diagnostic agents that were marketed in Japan as of 2019. The detection performance of H. pylori ATCC43504 standard strain and H. pylori antigen in commercial human fecal specimens were conducted.

RESULTS

The comparison of B (EIA) with Quick Chaser ^TM H. pylori (Q [IC]) revealed positive and negative concordance ratios of B (EIA) to Q (IC) of 100.0% (110/110) and 71.0% (22/31), respectively. A comparative test was conducted between B (EIA) and extracorporeal diagnostic agents that were marketed in Japan as of 2019, and B (EIA) was most sensitive on "detecting H. pylori antigen of ATCC43504 standard strain" and "detecting H. pylori antigen in commercial human fecal specimens," compared with other kits. Nine dissociated specimens that were negative for Q (IC) and positive for B (EIA) were confirmed. The measured value of B (EIA) in the dissociation samples were 1.3-87.4 cutoff index in the range that can be evaluated as negative by other fecal H. pylori antigen test kits, all the dissociation samples were H. pylori antigen-positive cases, and finally the cause of result divergence was presumed as false negative due to insufficient sensitivity of Q (IC).

CONCLUSION

B (EIA) that is based on the BLEIA method, which applies firefly luciferase luminescence, is more sensitive than stool antigen test kits that are currently marketed in Japan and is very useful in diagnosing H. pylori infection, especially in situations where noninvasive tests are preferred, such as in children.

Dramatic shift in the epidemiology of peptic ulcer in Japan: the impact of Helicobacter pylori eradication therapy

Helicobacter pylori eradication therapy was included with insurance coverage from 1999 onwards in Japan, with the incidence of peptic ulcer expected to decrease as a consequence. This study investigated the temporal dynamics of peptic ulcer in Japan and identified underlying contributory factors using mathematical models. We investigated the seroprevalence of H. pylori and analysed a snapshot of peptic ulcer cases. Ten statistical models that incorporated important events – H. pylori infection, the cohort effect, eradication therapy and the natural trend for reduction – were fitted to the case data. The hazard of infection with H. pylori was extracted from published estimates. Models were compared using the Akaike information criterion (AIC), and factor contributions were quantified using the coefficient of determination. The best-fit model indicated that 88.1% of the observed snapshot of cases (AIC = 289.2) included the effects of (i) H. pylori infection, (ii) the cohort effect and (iii) eradication therapy, as explanatory variables, the contributions of which were 80.8%, 4.0% and 3.2%, respectively. Among inpatients, a simpler model with (i) H. pylori infection only was favoured (AIC = 107.7). The time-dependent epidemiological dynamics of peptic ulcers were captured and H. pylori infection and eradication therapy explained ⩾84% of the dramatic decline in peptic ulcer occurrence.

Helicobacter pylori Infection Mass Screening for Children and Adolescents: a Systematic Review of Observational Studies

PURPOSE

Population-based Helicobacter pylori (H. pylori) screening and eradication for adults in areas with a high incidence of gastric cancer have been shown to be effective. The current status of H. pylori screening for young people, however, has not been sufficiently evaluated.

METHODS

A systematic review of population-based H. pylori screening of young people was performed using four databases (MEDLINE, EMBASE, the Cochrane Library, and ICHUSHI) and independently evaluated by two investigators. Studies were evaluated with regard to the country, region, screening method, target age, number of screened people, and rate of positive screening.

RESULTS

From 3231 studies, 39 studies were included (14 English original studies published in peer-review journals, 6 Japanese original studies, and 19 conference reports). These studies originated from 10 countries, with the largest number stemming from Japan (29 studies) followed by Germany (2 studies). Screening was performed using the urea breath test, blood antibodies, stool antigens, and urine antibodies. Five countries used the breath test as the first screening method, five used blood samples, two used stool antigens, and only Japan used urinary tests.

CONCLUSION

Screening for H. pylori in young people was reviewed based on reports from several countries, and findings suggest that local authorities considering screening for H. pylori in young people need to scrutinize the age and potential methods. Further research is required to determine the effectiveness of mid- to long-term H. pylori screening for young people.

Prevalence of Helicobacter pylori among residents and their environments in the Nara prefecture, Japan

BACKGROUND

Chronic infection with Helicobacter pylori, specifically cagA-positive strains, is associated with gastric cancer. Thus, measures to prevent H. pylori infection are required. This study was conducted to clarify the prevalence of H. pylori in the community to identify the infection source and comprehensively assess the risk of H. pylori infection.

METHODS

We collected 90 human faecal samples and 73 environmental samples (water, vegetable, and animal faecal samples) from the residents in an area with a high incidence of gastric cancer in Japan. Polymerase chain reaction assay was performed to detect the glmM housekeeping gene and the cagA virulence gene of H. pylori. A questionnaire survey was conducted, and the responses were analyzed statistically.

RESULTS

The glmM gene was detected in 18 of 90 (20%) faecal samples obtained from residents; among them, the cagA gene was detected in 33.3% (6/18), and in all who had undergone eradication therapy. H. pylori was not detected in environmental samples. However, contact with dogs (OR 3.89, 95% CI 1.15-13.15, P < 0.05) was associated with higher odds for glmM gene positivity in the questionnaire survey.

CONCLUSIONS

The prevalence of H. pylori and cagA-positive strains among the residents was low. However, the study results suggest a correlation between recurrent infection and cagA-positive H. pylori strains. Although H. pylori genes were not detected in living environments, an association between contact with dogs and a glmM positive status was revealed. Further investigations targeting community-dwelling healthy people and their living environments would be required for H. pylori infection control.

Gut microbiota changes related to Helicobacter pylori eradication with vonoprazan containing triple therapy among adolescents: a prospective multicenter study

Currently, it is unclear whether treating Helicobacter pylori (H. pylori) infection is safe among adolescents. This study aimed to evaluate the safety of H. pylori eradication therapy by examining gut microbiota changes in adolescents 3 months after the therapy. H. pylori-infected adolescents were enrolled in this study. Their stool samples were collected at the following three time points: before treatment, 1-2 days after completion of treatment, and time of eradication successful judgment. We assessed the relative abundance, alpha-diversity, and beta-diversity of the gut microbiota and adverse events. The number of isolated Actinobacteria decreased immediately after eradication therapy in the 16 students included in the study, and it returned to pretreatment condition at the eradication judgment point. There was no change in the relative abundance at genus level. The alpha-diversity was lost immediately after eradication therapy; however, it recovered at the time of eradication judgment, and it was restored to pretreatment condition. Meanwhile, none of the participants experienced serious adverse events. H. pylori eradication therapy is safe for adolescents with respect to gut microbiota changes associated with H. pylori eradication therapy. Therefore, further long-term evaluations of gut microbiota changes following eradication therapy are warranted.

Assessment of a novel method to detect clarithromycin-resistant Helicobacter pylori using a stool antigen test reagent

BACKGROUND

The resistance rate of Helicobacter pylori to clarithromycin (CAM) is high among infected children in Japan. Therefore, a new method for detecting CAM-resistant H. pylori using a minimally invasive technique is strongly desired. We aimed to investigate the clinical usefulness of our newly developed nested polymerase chain reaction-quenching probe (Nested PCR-QP) method using stool specimens.

METHODS

We first evaluated our method using a residual solution of the H. pylori stool antigen test for adolescents. Then, we evaluated our method using culture testing for adults.

RESULTS

Among 57 middle school students with H. pylori, the Nested PCR-QP test results of 53 (90.3%) were able to be analyzed. A total of 28 students had CAM resistance mutations. We found a genetic mutation in 28 students and no mutation in 23 students, and these results were consistent with those of PCR-direct sequencing. In the 23 adults who were diagnosed with H. pylori infection using the rapid urease test and culture testing, we were able to use Nested PCR-QP for analyzing 21 adults who tested positive in the stool H. pylori antigen test. The results obtained for all 21 adults were consistent with those obtained via the drug susceptibility test.

CONCLUSIONS

Our novel method could be useful for non-invasively detecting CAM resistance mutations in H. pylori. This may help select a drug to reduce eradication failure rates against H. pylori. Trial registration This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (no. UMIN000030632, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034977 ) on 29 December 2017.

Clinical impact of vonoprazan-based dual therapy with amoxicillin for H. pylori infection in a treatment-naïve cohort of junior high school students in Japan

BACKGROUND

Although 7-day triple therapy, consisting of vonoprazan, amoxicillin (AMO), and clarithromycin (CLA), is recommended for Helicobacter pylori (H. pylori) eradication in adults. However, the importance of reducing antibiotic use in pediatric patients is well recognized. Therefore, our aim was to compare the effectiveness and safety of vonoprazan and AMO (VA) dual therapy to vonoprazan-based (VAC) triple therapy for H. pylori eradication in a cohort of treatment-naïve junior high school students in Japan.

METHODS

This was a prospective observational study of second-year junior high-school students in Yurihonjo and Nikaho Cities, Japan. Between 2015 and 2017, 161 students were treated with VAC-triple therapy (20 mg vonoprazan, 750 mg AMO, and 200 mg CLA, twice a day for 7 days), while 60 students were treated with VA-dual therapy (20 mg vonoprazan and 750 mg AMO, twice a day for 7 days) since 2018. The success rate of H. pylori eradication and drug-related adverse events were compared between the two therapy groups. Intention-to-treat (ITT) and per-protocol (PP) analyses were performed.

RESULTS

Groups were comparable at baseline. The ITT and PP eradication rates were 85.0% (95% confidence interval [CI] 75.8-94.2%) and 86.4% (95% CI 77.4-95.5%), respectively, with VA-dual therapy and 82.0% (95% CI 76.0%-87.9%) and 84.1% (95% CI 78.3-89.8%), respectively, with VAC-triple therapy. VA-dual therapy was non-inferior to VAC-triple therapy (ITT, p = 0.018; PP, p = 0.020). The adverse event rate was 10.0% with VA-dual therapy and 19.8% with VAC-triple therapy (p = 0.108).

CONCLUSIONS

The effectiveness of VA-dual therapy was comparable to that of VAC-triple therapy in H. pylori treatment-naïve junior high school students, while reducing the use of antibiotics.

A Helicobacter pylori screening and treatment program to eliminate gastric cancer among junior high school students in Saga Prefecture: a preliminary report

BACKGROUND

To present the strategies and preliminary findings of the first 3 years after implementing a Helicobacter pylori screening and eradication program to prevent gastric cancer in Saga Prefecture.

METHODS

A screening and treatment program to eradicate H. pylori from third-grade junior high students was started in Saga Prefecture in 2016, using local governmental grants. Screening was with urinary anti-H. pylori antibody tests, followed by H. pylori stool antigen tests for students who were antibody positive. Those positive on both tests underwent H. pylori eradication by triple therapy based on a potassium-competitive acid blocker.

RESULTS

From 2016 to 2018, the participation rate was 83.1% and the H. pylori infection rate was 3.1% (660/21,042). The participation rates were higher in 2017 (85.4%) and 2018 (85.9%) compared with 2016 (78.5%) (P < 0.0001), and the infection rate also decreased in a time-dependent manner (2016: 3.6%, 2017: 3.3%, 2018: 2.5%, P = 0.0001). In total, 501 students positive for H. pylori received eradication therapy (85.1% success) and adverse events occurred in 20 of these (4.0%). However, no serious complications occurred.

CONCLUSIONS

The H. pylori screening and eradication project for school students in Saga Prefecture has started successfully and we have seen both a steady increase in the participation rate and a steady decrease in the infection rate, without major safety concerns.

Evaluation of a Novel Stool Antigen Rapid Test Kit for Detection of Helicobacter pylori Infection

The Quick Chaser H. pylori (QCP), which is a novel antigen detection kit for Helicobacter pylori, was developed recently. The previous examination kits targeted the catalase of H. pylori; however, this new test kit, to the best of our knowledge, is the first kit to target the flagellar protein of H. pylori The present study aimed to evaluate the efficacy of QCP compared with that of the already commercially available rapid test kit Testmate Rapid Pylori Antigen (TRP). TRP and QCP were utilized in 71 participants. The positive and negative concordance ratios of QCP to TRP were 100% (57/57) and 92.9% (13/14), respectively. Sensitivity based on the rapid urease test and culture test was 92.3%. Results of the dilution sensitivity test showed that QCP was eight times more sensitive to an H. pylori standard strain and the clarithromycin (CAM)-resistant clinical isolate and four times more sensitive to a CAM-susceptible clinical isolate than TRP. For the cross-reactivity test, 27 strains that exist in human feces, such as the Helicobacter genus, Bifidobacterium genus, Lactobacillus genus, and other resident bacteria, were selected. The results obtained using QCP were all negative, and no cross-reaction was observed. In conclusion, compared with TRP, QCP can detect H. pylori using clinical specimens with high sensitivity, regardless of CAM susceptibility and tolerance. No cross-reactivity was observed with other intestinal bacteria in humans. The kit is considered extremely useful in clinical settings.

Estimating the Force of Infection with Helicobacter pylori in Japan

Background

Although the seroprevalence against Helicobacter pylori (H. pylori) in Japan has declined over the birth year, Japanese people have yet exhibited a relatively high risk of gastric cancer. The present study employed mathematical models to estimate the time- and age-dependent force of infection with H. pylori in Japan, predicting the future seroprevalence by time and age.

Methods

We investigated the published seroprevalence data against H. pylori in Japan from 1980–2018. Solving the McKendrick partial differential equation model, the seroprevalence was modeled as a function of survey year and age. Maximum likelihood estimation was conducted to estimate parameters governing the time- and age-dependent force of infection.

Results

Among all fitted models, the time-dependent and age-independent model with an exponentially decaying force of infection over years was most favored. Fitted models indicated that the force of infection started to decrease during and/or shortly after the World War II. Using the parameterized model, the predicted fraction seropositive at the age of 40 years in 2018 was 0.22, but it is expected to decrease to 0.13 in 2030 and 0.05 in 2050, respectively.

Conclusion

The time dependence was consistent with the decline in the force of infection as a function of the birth year. The force of infection has continuously and greatly declined over time, implying the diminished transmission of H. pylori through the time course and small chance of persistence. These findings are critical to anticipate the future decline in gastric cancer incidence.

Serum Pepsinogen Values in Japanese Junior High School Students With Reference to Helicobacter Pylori Infection

Background

Distributions of serum pepsinogen (PG) values were assessed in Helicobacter pylori-infected and non-infected junior high school students (aged 12–15 years) in Japan.

Methods

All junior high school students (1,225 in total) in Sasayama city, who were basically healthy, were asked to provide urine and serum samples, which were used to measure urine and serum H. pylori antibodies using ELISA kits and PG values. The subjects, whose urine and serum antibodies were both positive, were considered H. pylori infected.

Results

Of the 187 subjects who provided urine and blood samples, 8 were infected, 4 had discrepant results, 4 had negative serum antibody titers no less than 3.0 U/ml, and 171 were non-infected. In the H. pylori non-infected subjects, the median PG I and PG II values and PG I to PG II ratio (PG I/II) were 40.8 ng/mL, 9.5 ng/mL, and 4.4, respectively, whereas in the infected subjects, these values were 55.4 ng/mL, 17.0 ng/mL, and 3.3, respectively (each P < 0.01). In the non-infected subjects, PG I and PG II were significantly higher in males than in females (P < 0.01).

Conclusions

The PG I and PG II values were higher, and the PG I/II was lower in H. pylori infected students than in non-infected students. In H. pylori non-infected students, males showed higher PG I and PG II values than females. The distributions of PG values in junior high school students differed from those in adults.

Gut microbiome can be restored without adverse events after Helicobacter pylori eradication therapy in teenagers

OBJECTIVES

The effect of Helicobacter pylori eradication on the gut microbiota of teenagers is unknown; hence, this study aimed to assess changes in the gut microbiome after H. pylori eradication therapy in teenagers.

MATERIALS AND METHODS

Changes in gut microbiota before and after H. pylori eradication were prospectively investigated in eight students without any underlying diseases, via next-generation sequencing of 16S rDNA. Twenty-four stool samples were collected, and operational taxonomic unit analysis was performed. As secondary analyses, alpha and beta diversity were evaluated. Furthermore, pre-treatment microbiome compositions were compared with those 1 week and 2 months after treatment.

RESULTS

Alpha diversity analysis revealed that both species richness and evenness were recovered to pre-treatment levels at 2 months after eradication therapy. Slight but non-significant differences were observed in bacterial species abundance between pre- and post-treatment samples, upon beta diversity analysis. Although the relative abundance of Bacteroidetes tended to increase and that of Actinobacteria significantly decreased immediately after eradication therapy, the taxonomic composition was similar to that before treatment and at 2 months post-eradication. However, two students showed significant changes in the gut microbiota in relative abundances at the level of the phylum, class, and order.

CONCLUSIONS

Although H. pylori eradication therapy caused short-term dysbiosis, microbial diversity was restored in healthy teenagers. However, as the relative abundance of gut microbiota in some cases remained altered, the effect of H. pylori eradication therapy on the gut microbiome should be continuously monitored.

Diagnostic Accuracy of Latex Agglutination Turbidimetric Immunoassay in Screening Adolescents for Helicobacter pylori Infection in Japan

BACKGROUND/AIMS

Serologic tests are commonly used for screening Helicobacter pylori infection because they not only provide quick results but also are inexpensive. A new latex agglutination serum antibody assay (LZ test) has been developed and it is expected to be as effective as conventional assays. This study aimed to calculate a reliable cutoff value for the LZ test and to estimate the sensitivity and specificity of the cutoff value in screening adolescents for H. pylori infection in Japan.

METHODS

We screened junior high school students in Akita Prefecture, Japan, for H. pylori infection. We used the data of 213 such students who underwent H. pylori stool antigen (HpSA) tests in 2016. The students who had positive results with HpSA tests were diagnosed with H. pylori infection. Of the 213 students, 209 underwent the LZ test.

RESULTS

The prevalence rate of H. pylori infection was 3.8% (8/209). The area under the curve for the LZ test was 0.88. The cutoff value of the LZ test was determined to be 3.1 U/mL. At this value, the sensitivity and specificity were 87.5 and 91.5%, respectively.

CONCLUSION

The accuracy of the LZ test in adolescents was well balanced for sensitivity and specificity as well as for tolerable results.

Safety of first-line triple therapy with a potassium-competitive acid blocker for Helicobacter pylori eradication in children

BACKGROUND

Helicobacter pylori infection is a risk factor for gastric cancer, and it has been reported that eradication of H. pylori is effective for preventing such cancer. Recently, H. pylori eradication has been performed in children as first-line therapy against gastric cancer. Here, we report use of triple therapy with a potassium-competitive acid blocker (P-CAB) for H. pylori eradication in children.

METHODS

H. pylori infection testing and eradication therapy began in fiscal year 2015 in junior high school students located in Yurihonjo city and Nikaho city, Akita prefecture, Japan. Urine-based immunochromatography, stool antigen enzyme-linked immunosorbent assay tests, and serum antibody tests were performed as the initial screening examination. Those who tested positive on one of the three examinations then underwent a urea breath test (¹³C-UBT). Those who tested positive on ¹³C-UBT and expressed the desire to undergo H. pylori eradication then received eradication therapy comprising 20 mg P-CAB, 750 mg amoxicillin, and 200 mg clarithromycin twice a day for 7 days. At least 8 weeks after treatment, eradication success was evaluated using ¹³C-UBT.

RESULTS

A total of 118 students received eradication therapy. Eradication rates were 81.3% (95% confidence interval: 74.3-88.4, 96/118) in ITT analysis and 85.7% (95% confidence interval: 79.1-92.9 96/112) in PP analysis. Adverse effects associated with eradication therapy were observed in 25 of 118 subjects (21.1%), seven of whom required hospital treatment (rash in five, vomiting in two). All seven subjects either discontinued therapy or were administered anti-allergy drugs, which resulted in swift alleviation of symptoms.

CONCLUSIONS

First-line triple therapy with a P-CAB for H. pylori eradication in children was found to be safe.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

Changing epidemiology of Helicobacter pylori in Japan

Helicobacter pylori (H. Pylori) is known as the most important cause of gastric cancer. The prevalence of H. pylori infection varies widely by geographic area, age, and socioeconomic status. In Japan, H. pylori infection has been highly correlated with the incidence rate of gastric cancer, and a reduction in H. pylori infection is therefore crucial for decreasing the incidence of gastric cancer, especially at the population level. Infection occurs during childhood, commonly before 5 years of age. In Japan, where gastric cancer has ranked as the most common cancer by incidence and mortality for the last several decades, the prevalence of H. pylori infection has dramatically declined by birth cohort effect, mainly due to improvements in the general hygiene environment in childhood. Older generations born before around 1950 show a high prevalence of around 80-90 %, decreasing with age to reach around 10 % or less in those born around the 1990s, and less than 2 % for children born after the year 2000. This change will have generational effects on gastric cancer prevention strategies, both primary and secondary. The risk-stratified approach to gastric cancer prevention should be considered in Japan and other countries which have similarly experienced rapid economic development.

The administrative project of Helicobacter pylori infection screening among junior high school students in an area of Japan with a high incidence of gastric cancer

OBJECTIVE

Helicobacter pylori infection is a common chronic infection that is closely associated with gastric cancer, known to be decreasing worldwide. We set up an administrative project of screening examination for H. pylori infection in junior high school students in Akita Prefecture to investigate the current prevalence of H. pylori infection in childhood in an area where the incidence of gastric cancer is particularly high.

SUBJECTS AND METHODS

All students in their second or third year of junior high school (13 to 15 years old) in two cities in Akita Prefecture were recruited. First, a urine-based enzyme-linked immunosorbent assay for detection of H. pylori antibody was performed. Then, a ¹³C-urea breath test (¹³C-UBT) was carried out in students who tested positive on the urinary test. Written informed consent was obtained from all participants and their parents.

RESULTS

A total of 1813 students were recruited in this study; 1765 (97.3%) students agreed to participate in this project and underwent a screening examination. Among 96 students (5.4%) testing positive for H. pylori on the initial screening examination, 90 (93.7%, 90/96) underwent a subsequent ¹³C-UBT, and 85 (4.8%, 85/1765) were diagnosed as positive for H. pylori.

CONCLUSIONS

The current prevalence of H. pylori infection among students was low even in an area of Japan with a high incidence of gastric cancer.

Changing epidemiology of Helicobacter pylori in Japan

Helicobacter pylori (H. Pylori) is known as the most important cause of gastric cancer. The prevalence of H. pylori infection varies widely by geographic area, age, and socioeconomic status. In Japan, H. pylori infection has been highly correlated with the incidence rate of gastric cancer, and a reduction in H. pylori infection is therefore crucial for decreasing the incidence of gastric cancer, especially at the population level. Infection occurs during childhood, commonly before 5 years of age. In Japan, where gastric cancer has ranked as the most common cancer by incidence and mortality for the last several decades, the prevalence of H. pylori infection has dramatically declined by birth cohort effect, mainly due to improvements in the general hygiene environment in childhood. Older generations born before around 1950 show a high prevalence of around 80-90 %, decreasing with age to reach around 10 % or less in those born around the 1990s, and less than 2 % for children born after the year 2000. This change will have generational effects on gastric cancer prevention strategies, both primary and secondary. The risk-stratified approach to gastric cancer prevention should be considered in Japan and other countries which have similarly experienced rapid economic development.

Helicobacter pylori Eradication to Eliminate Gastric Cancer: The Japanese Strategy

Helicobacter pylori eradication therapy for chronic gastritis achieved world-first coverage by the Japanese national health insurance scheme in 2013, making a dramatic decrease of gastric cancer-related deaths more realistic. Combining H pylori eradication therapy with endoscopic surveillance can prevent the development of gastric cancer. Even if it develops, most patients are likely to be diagnosed at an early stage, possibly resulting in fewer gastric cancer deaths. Success with the elimination of gastric cancer in Japan could lead other countries with a high incidence to consider a similar strategy, suggesting the potential for elimination of gastric cancer around the world.

Screening to Identify and Eradicate Helicobacter pylori Infection in Teenagers in Japan

The purpose of this study was to elucidate the prevalence and effect of Helicobacter pylori infection in Japanese teenagers. The study subjects were students ages 16 to 17 from one high school studied between 2007 and 2013. Students who tested positive on this screening examination underwent esophagogastroduodenoscopy and biopsy samples to determine their H pylori status using culture and histology. Cure of H pylori infections was determined by urea breath test. The low rate of prevalence of H pylori infection in present Japanese teenagers makes it possible and cost effective to perform examinations and carry out treatment of this infection in nationwide health screenings of high school students.

Gastric mucosa in Mongolian and Japanese patients with gastric cancer and Helicobacter pylori infection

AIM: To investigate the characteristics of gastric cancer and gastric mucosa in a Mongolian population by comparison with a Japanese population.

METHODS: A total of 484 Mongolian patients with gastric cancer were enrolled to study gastric cancer characteristics in Mongolians. In addition, a total of 208 Mongolian and 3205 Japanese consecutive outpatients who underwent endoscopy, had abdominal complaints, no history of gastric operation or Helicobacter pylori eradication treatment, and no use of gastric secretion inhibitors such as histamine H₂-receptor antagonists or proton pump inhibitors were enrolled. This study was conducted with the approval of the ethics committees of all hospitals. The triple-site biopsy method was used for the histologic diagnosis of gastritis and H. pylori infection in all Mongolian and Japanese cases. The infection rate of H. pylori and the status of gastric mucosa in H. pylori-infected patients were compared between Mongolian and Japanese subjects. Age (± 5 years), sex, and endoscopic diagnosis were matched between the two countries.

RESULTS: Approximately 70% of Mongolian patients with gastric cancer were 50-79 years of age, and approximately half of the cancers were located in the upper part of the stomach. Histologically, 65.7% of early cancers exhibited differentiated adenocarcinoma, whereas 73.9% of advanced cancers displayed undifferentiated adenocarcinoma. The infection rate of H. pylori was higher in Mongolian than Japanese patients (75.9% vs 48.3%, P < 0.0001). When stratified by age, the prevalence was highest among young patients, and tended to decrease in patients aged 50 years or older. The anti-East-Asian CagA-specific antibody was negative in 99.4% of H. pylori-positive Mongolian patients. Chronic inflammation, neutrophil activity, glandular atrophy, and intestinal metaplasia scores were significantly lower in Mongolian compared to Japanese H. pylori-positive patients (P < 0.0001), with the exception of the intestinal metaplasia score of specimen from the greater curvature of the upper body. The type of gastritis changed from antrum-predominant gastritis to corpus-predominant gastritis with age in both populations.

CONCLUSION: Gastric cancer was located in the upper part of the stomach in half of the Mongolian patients; Mongolian patients were infected with non-East-Asian-type H. pylori.

Time Trends in Helicobacter pylori Infection and Atrophic Gastritis Over 40 Years in Japan

BACKGROUND

Helicobacter pylori infection produces progressive mucosal damage that may eventually result in gastric cancer. We studied the changes that occurred in the presence and severity of atrophic gastritis and the prevalence of H. pylori infection that occurred coincident with improvements in economic and hygienic conditions in Japan since World War II.

MATERIALS AND METHODS

The prevalence of H. pylori infection and histologic grades of gastric damage were retrospectively evaluated using gastric biopsy specimens obtained over a 40-year period. Gastric atrophy and intestinal metaplasia were scored using the updated Sydney classification system.

RESULTS

The prevalence of H. pylori and severity of atrophy were examined in 1381 patients including 289 patients examined in the 1970s (158 men; mean age, 44.9 years), 787 in the 1990s (430 men; 44.2 years), and 305 in the 2010s (163 men; 53.2 years). Overall, the prevalence of H. pylori infection decreased significantly from 74.7% (1970s) to 53% (1990s) and 35.1% (2010s) (p < .01). The prevalence of atrophy in the antrum and corpus was significantly lower in the 2010s (33, 19%, respectively) compared to those evaluated in either the 1970s (98, 82%) (p < .001) or 1990s (80, 67%) (p < .001). The severity of atrophy and intestinal metaplasia also declined remarkably among those with H. pylori infection.

CONCLUSIONS

There has been a progressive and rapid decline in the prevalence of H. pylori infection as well a fall in the rate of progression of gastric atrophy among H. pylori-infected Japanese coincident with the westernization and improvements in economic and hygienic conditions in Japan since World War II.

Prevalence of Helicobacter pylori infection with healthy subjects in Japan

BACKGROUND AND AIM

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.

CONCLUSION

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.

Strategies for eliminating death from gastric cancer in Japan

In Japan, efforts have been directed toward improving the detection of early gastric cancer by double contrast radiography and endoscopy, since early cancer has a good prognosis, resulting in Japan having the world's best diagnostic system for early gastric cancer. The 5-year survival rate of gastric cancer patients in Japan is much higher than in Western countries by the development of endoscopic treatment for early gastric cancer. In February 2013, Japanese national health insurance cover for H. pylori eradication therapy was expanded to patients with H. pylori-associated gastritis, a type of chronic gastritis. H. pylori-associated gastritis causes gastric and duodenal ulcers and gastric polyps, therefore, providing treatment for this gastritis is likely to substantially decrease the prevalence of both gastric and duodenal ulcer and gastric cancer. Patients with gastritis are tested for H. pylori infection and those who are positive receive eradication therapy followed by periodic endoscopic surveillance. If such an approach is pursued further in Japan, gastric cancer deaths will show a dramatic decline after 10-20 years.

Roadmap to eliminate gastric cancer with Helicobacter pylori eradication and consecutive surveillance in Japan

In Japan, the annual number of deaths from gastric cancer is approximately 50,000 and there has been no change over the last 50 years. So far, all efforts have been directed toward improving the detection of early gastric cancer by barium X-ray and endoscopy, since early cancer has a good prognosis, resulting in Japan having the best diagnostic capability for early gastric cancer worldwide. The 5-year survival rate of gastric cancer patients exceeds 60 % in Japan and is much higher than that in Europe and the US (20 %) because of this superior diagnosis of early gastric cancer. In February 2013, national health insurance coverage for Helicobacter pylori eradication therapy to treat H. pylori-associated chronic gastritis became available in Japan. H. pylori-associated gastritis leads to development of gastric and duodenal ulcers and gastric polyps. Therefore, providing treatment for gastritis is likely to substantially decrease the prevalence of both gastric and duodenal ulcers and polyps. Because treatment for H. pylori-associated gastritis, which leads to atrophic gastritis and gastric cancer, is now covered by health insurance in Japan, a strategy to eliminate gastric cancer-related deaths by taking advantage of this innovation was planned. According to this strategy, patients with gastritis will be investigated for H. pylori infection and those who are positive will receive eradication therapy followed by periodic surveillance. If this strategy is implemented, deaths from gastric cancer in Japan will decrease dramatically after 10-20 years.

Diagnostic accuracy of urine-based kits for detection of Helicobacter pylori antibody in children

BACKGROUND

Rapid urine-HpAb is reported to be a reliable test of Helicobacter pylori infection in adults, but there are no data on the application of the test in children. The aim of this study was to evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (urine-HpELISA) and immunochromatography (rapid urine-HpAb) kit for anti-H. pylori immunoglobulin G antibody in children. We compared its sensitivity and specificity in reference to the (13) C-urea-breath test (UBT) and H. pylori stool antigen test (HpSA).

METHODS

In total, 101 Japanese children without significant upper-abdominal symptoms were included (mean age, 7.1 years; range 2-15 years). Their sensitivity and specificity were evaluated in reference to the UBT and HpSA.

RESULTS

Thirty-seven children were judged H. pylori-positive and 64 negative by the UBT and HpSA. No discrepancy in the results was observed between UBT and HpSA. Urine-HpELISA showed 91.9% sensitivity and 96.9% specificity with an accuracy of 95.0%. Rapid urine-HpAb showed 78.4% sensitivity and 100% specificity with an accuracy of 92.1%. Seven false negative results for rapid urine-HpAb were from children aged younger than 10 years, and their antibody titers of urine-HpELISA were lower than true positives.

CONCLUSIONS

For the diagnosis of H. pylori infection in Japanese children, both tests are non-invasive, inexpensive, reliable and easy-to-perform methods giving satisfactory accuracy, although the sensitivity of the rapid urine-HpAb kit was inferior to that of the urine-HpELISA kit, especially in children aged younger than 10 years, showing relatively low titer of H. pylori antibody.

A Study on the Efficacy of Proton Pump Inhibitors in Helicobacter pylori-Negative Primary Care Patients with Dyspepsia in Japan

Background/Aims

There have been few studies on the efficacy of proton pump inhibitors and the doses required to treat dyspeptic symptoms observed in clinical practice. The aim of this study was to compare the efficacy of different doses of omeprazole and different administration methods in Helicobacter pylori-negative, dyspeptic patients.

Methods

Patients with chronic upper abdominal symptoms within the previous 3 months were randomly divided into three groups: a daily, omeprazole 20 mg treatment group (OPZ20, n=61); a daily, omeprazole 10 mg treatment group (OPZ10, n=72); and an on-demand omeprazole 20 mg treatment group (on-demand, n=62). After 4 weeks of administration of the drug, symptom improvement rates were evaluated based on the Overall Global Severity score.

Results

The rates of symptom improvement after 4 weeks of treatment were 65.6% (40/61) in the OPZ20 group, 47.2% (34/72) in the OPZ10 group, and 50.0% (31/62) in the on-demand group. The OPZ20 group exhibited a significantly higher improvement rate (p=0.034) than the OPZ10 group. The OPZ20 group had significant improvements in regurgitation, postprandial fullness, vomiting, and bloating compared with the OPZ10 group.

Conclusions

Daily treatment with 20 mg of omeprazole was efficient in treating upper abdominal symptoms. Trial registration: ClinicalTrials.gov, number UMIN000002621.