Acquisition versus loss of Helicobacter pylori infection in Japan: results from an 8-year birth cohort study

Helicobacter pylori infection in infant rhesus macaque monkeys is associated with an altered lung and oral microbiome

It is estimated that more than half of the world population has been infected with Helicobacter pylori. Most newly acquired H. pylori infections occur in children before 10 years of age. We hypothesized that early life H. pylori infection could influence the composition of the microbiome at mucosal sites distant to the stomach. To test this hypothesis, we utilized the infant rhesus macaque monkey as an animal model of natural H. pylori colonization to determine the impact of infection on the lung and oral microbiome during a window of postnatal development. From a cohort of 4-7 month-old monkeys, gastric biopsy cultures identified 44% of animals infected by H. pylori. 16S ribosomal RNA gene sequencing of lung washes and buccal swabs from animals showed distinct profiles for the lung and oral microbiome, independent of H. pylori infection. In order of relative abundance, the lung microbiome was dominated by the phyla Proteobacteria, Firmicutes, Bacteroidota, Fusobacteriota, Campilobacterota and Actinobacteriota while the oral microbiome was dominated by Proteobacteria, Firmicutes, Bacteroidota, and Fusobacteriota. In comparison to the oral cavity, the lung was composed of more genera and species that significantly differed by H. pylori status, with a total of 6 genera and species that were increased in H. pylori negative infant monkey lungs. Lung, but not plasma IL-8 concentration was also associated with gastric H. pylori load and lung microbial composition. We found the infant rhesus macaque monkey lung harbors a microbiome signature that is distinct from that of the oral cavity during postnatal development. Gastric H. pylori colonization and IL-8 protein were linked to the composition of microbial communities in the lung and oral cavity. Collectively, these findings provide insight into how H. pylori infection might contribute to the gut-lung axis during early childhood and modulate future respiratory health.

Prevalence of Histological Gastritis in a Community Population and Association with Epigastric Pain

BACKGROUND AND AIMS

Gastritis is a common histological diagnosis, although the prevalence is decreasing in developed populations, alongside decreasing prevalence of H. pylori infection. We sought to determine the prevalence of the etiology of gastritis in a Swedish population sample and to analyze any associations with symptoms, an area of clinical uncertainty.

METHODS

Longitudinal population-based study based in Östhammar, Sweden. A randomly sampled adult population completed a validated gastrointestinal symptom questionnaire (Abdominal Symptom Questionnaire, ASQ) in 2011 (N = 1175). Participants < 80 years of age and who were eligible were invited to undergo esophagogastroduodenoscopy (EGD) (N = 947); 402 accepted and 368 underwent EGD with antral and body biopsies (average 54.1 years, range 20-79 years; 47.8% male) with H. pylori serology.

RESULTS

Gastritis was found in 40.2% (148/368; 95% CI 35.2-45.2%). By rank, the most common histological subtype was reactive (68/148; 45.9%), then H. pylori (44/148; 29.7%), chronic non-H. pylori (29/148; 19.6%), and autoimmune (4/148; 2.7%). Gastritis was significantly associated with older age and H. pylori status (p < 0.01). Gastritis subjects were divided into three histological categories: chronic inactive inflammation, autoimmune gastritis, and active inflammation; there was no difference in the presence of upper gastrointestinal symptoms when categories were compared to cases with no pathological changes. Functional dyspepsia or gastroesophageal reflux were reported in 25.7% (38/148) of those with gastritis (any type or location) versus 34.1% (75/220) with no pathological changes (p = 0.32). Epigastric pain was more common in chronic H. pylori negative gastritis in the gastric body (OR = 3.22, 95% CI 1.08-9.62).

CONCLUSION

Gastritis is common in the population with a prevalence of 40% and is usually asymptomatic. Chronic body gastritis may be associated with epigastric pain, but independent validation is required to confirm these findings. Clinicians should not generally ascribe symptoms to histological gastritis.

Helicobacter pylori Infection in Infant Rhesus Macaque Monkeys is Associated with an Altered Lung and Oral Microbiome

Background

It is estimated that more than half of the world population has been infected with Helicobacter pylori. Most newly acquired H. pylori infections occur in children before 10 years of age. We hypothesized that early life H. pylori infection could influence the composition of the microbiome at mucosal sites distant to the stomach. To test this hypothesis, we utilized the infant rhesus macaque monkey as an animal model of natural H. pylori colonization to determine the impact of infection on the lung and oral microbiome during a window of postnatal development.

Results

From a cohort of 4-7-month-old monkeys, gastric biopsy cultures identified 44% of animals infected by H. pylori. 16S ribosomal RNA gene sequencing of lung washes and buccal swabs from animals showed distinct profiles for the lung and oral microbiome, independent of H. pylori infection. In relative order of abundance, the lung microbiome was dominated by the phyla Proteobacteria, Firmicutes, Bacteroidota, Fusobacteriota, Campilobacterota and Actinobacteriota while the oral microbiome was dominated by Proteobacteria, Firmicutes, Bacteroidota, and Fusobacteriota. Relative to the oral cavity, the lung was composed of more genera and species that significantly differed by H. pylori status, with a total of 6 genera and species that were increased in H. pylori negative infant monkey lungs. Lung, but not plasma IL-8 concentration was also associated with gastric H. pylori load and lung microbial composition.

Conclusions

We found the infant rhesus macaque monkey lung harbors a microbiome signature that is distinct from that of the oral cavity during postnatal development. Gastric H. pylori colonization and IL-8 protein were linked to the composition of microbial communities in the lung and oral cavity. Collectively, these findings provide insight into how H. pylori infection might contribute to the gut-lung axis during early childhood and modulate future respiratory health.

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, clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage in healthy school-aged children: A case-control study

BACKGROUND

Helicobacter pylori is acquired largely in early childhood, but its association with symptoms and indirect biomarkers of gastric damage in apparently healthy children remains controversial. We aimed to relate persistent H. pylori infection in apparently healthy school-aged children with clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage using a case-control design.

MATERIALS AND METHODS

We followed up 83 children aged 4-5 years with persistent H. pylori infection determined by stool antigen detection and/or a urea breath test and 80 noninfected matched controls from a low-income to middle-income, periurban city in Chile for at least 3 years. Monitoring included clinical visits every 4 months and annual assessment by a pediatric gastroenterologist. A blood sample was obtained to determine laboratory parameters potentially associated with gastric damage (hemogram and serum iron and ferritin levels), biomarkers of inflammation (cytokines, pepsinogens I and II, and tissue inhibitor metalloproteinase 1), and expression of cancer-related genes KLK1, BTG3, and SLC5A8.

RESULTS

Persistently infected children had higher frequency of epigastric pain on physical examination (40% versus 16%; P = 0.001), especially from 8 to 10 years of age. No differences in anthropometric measurements or iron-deficiency parameters were found. Persistent infection was associated with higher levels of pepsinogen II (median 12.7 ng/mL versus 9.0 ng/mL; P < 0.001); no difference was observed in other biomarkers or gene expression profiles.

CONCLUSIONS

H. pylori infection in apparently asymptomatic school-aged children is associated with an increase in clinical symptoms and in the level of one significant biomarker, pepsinogen II, suggesting early gastric involvement.

Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false-negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection-induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton-pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%-0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%-0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection-induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high-risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high-risk subgroup of this understudied population is especially important.

Maternal H. pylori seropositivity is associated with gestational hypertension but is irrelevant to fetal growth and development in early childhood

BACKGROUND

Helicobacter pylori infection is known to alter growth-related hormones and affect growth in young children. However, it is still unknown whether maternal H. pylori infection has an impact on the levels of cord blood growth-related hormones and whether this can predict intrauterine growth restriction and poor physical and neurodevelopmental outcomes in children. This study aimed to examine associations between maternal H. pylori infection and pregnancy-related adverse events, fetal growth and early childhood development.

METHODS

In this prospective cohort study, we recruited singleton pregnant women without major medical illnesses from January 2014 to January 2015. Seropositivity for H. pylori was defined as > 12 U/ml of anti-H. pylori IgG in maternal serum. Demographic data and pregnancy-related medical issues of the cohort were documented. Cord blood levels of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), insulin, and ghrelin were determined using ELISA. The growth of the included neonates was monitored annually for up to 3 years, and cognitive development was assessed using the comprehensive developmental inventory for infants and toddlers (CDIIT) test 3 years after birth.

RESULTS

Of the 106 enrolled women, 25 (23.6%) were H. pylori-seropositive. Maternal H. pylori seropositivity was correlated with a higher risk of developing gestational hypertension (GH) (12% vs. 1.2%, p = 0.04) and lower cord blood levels of IGF-1 (< 35 ng/ml, 70.0% vs. 40.7%, p = 0.02) and IGFBP-3 (< 1120 ng/ml, 100.0% vs. 76.3%, p = 0.02) compared with the seronegative women. No significant impacts on birth weight, childhood growth and cognitive development were found to be correlated with maternal H. pylori seropositivity during pregnancy.

CONCLUSIONS

Maternal H. pylori infection during pregnancy was more likely to lead to the development of GH, but was not correlated with fetal and childhood growth and development. In addition to close monitoring of hypertension, H. pylori eradication can be considered for mothers with H. pylori infection.

The Predictive Factors of Responsiveness to Proton Pump Inhibitor Therapy for Eosinophilic Esophagitis

Approximately half of patients with eosinophilic esophagitis (EoE) respond clinically and histologically to proton pump inhibitor (PPI) therapy. Although recent guidelines suggest that PPI-responders and non-responders were included in EoE, it is important to investigate the predictive factors of PPI- responsiveness. This study aimed to determine the rate of PPI- responders and compare the characteristics of PPI-responders and non-responders. Fifty-nine patients with esophageal eosinophilia received PPI therapy for eight weeks, and its efficacy was assessed. PPI- responsiveness was diagnosed based on the relief in symptoms and reduction of intraepithelial eosinophilic infiltration to <15 per high-power field (hpf) after PPI therapy. Multivariate analysis was performed to identify factors associated with PPI-responders. Of the 59 patients, 41 (69.5%) were diagnosed with PPI-responders. The rate of gastrointestinal (GI) screening in the indications for endoscopy was significantly higher in patients with PPI- responders than in those with non-responders. On multivariate analysis, GI screening and presence of reflux esophagitis was associated with an increased odds ratio (OR) of PPI-responders, but presence of rings with a decreased OR of PPI-responders. Presence of reflux esophagitis and absence of rings on endoscopy especially during GI screening might be significant predictive factors for PPI response in patients with EoE.

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.

Diversity of macaque microbiota compared to the human counterparts

Studies on the microbial communities in non-human primate hosts provide unique insights in both evolution and function of microbes related to human health and diseases. Using 16S rRNA gene amplicon profiling, we examined the oral, anal and vaginal microbiota in a group of non-captive rhesus macaques (N = 116) and compared the compositions with the healthy communities from Human Microbiome Project. The macaque microbiota was dominated by Bacteroidetes, Firmicutes and Proteobacteria; however, there were marked differences in phylotypes enriched across body sites indicative of strong niche specialization. Compared to human gut microbiota where Bacteroides predominately enriched, the surveyed macaque anal community exhibited increased abundance of Prevotella. In contrast to the conserved human vaginal microbiota extremely dominated by Lactobacillus, the macaque vaginal microbial composition was highly diverse while lactobacilli were rare. A constant decrease of the vaginal microbiota diversity was observed among macaque samples from juvenile, adult without tubectomy, and adult with tubectomy, with the most notable distinction being the enrichment of Halomonas in juvenile and Saccharofermentans in contracepted adults. Both macaque and human oral microbiota were colonized with three most common oral bacterial genera: Streptococcus, Haemophilus and Veillonella, and shared relatively conserved communities to each other. A number of bacteria related to human pathogens were consistently detected in macaques. The findings delineate the range of structure and diversity of microbial communities in a wild macaque population, and enable the application of macaque as an animal model for future characterization of microbes in transmission, genomics and function.

Is the incidence of esophageal adenocarcinoma increasing in Japan? Trends from the data of a hospital-based registration system in Akita Prefecture, Japan

BACKGROUND

At present, squamous cell carcinoma accounts for most esophageal cancers in Japan; however, there is concern that the incidence of esophageal adenocarcinoma in Japan is increasing in comparison to Western countries. Akita Prefecture, with a population of 1 million, has the highest rate of esophageal cancer-associated mortality in Japan; the vast majority of these cases are squamous cell carcinoma. The aim of the present study was to investigate the latest trends in the incidence of esophageal adenocarcinoma in Akita Prefecture using a registration system.

METHODS

We examined the data from a collaborative hospital-based registration system for cancer patients. Eleven of the main hospitals in Akita Prefecture participate in this system, which covers 90% of the cancer cases in the region and which provides near population-based data. Using this registration system, we examined the sequential trends in the percentage of adenocarcinoma cases in relation to total esophageal cancer cases in Akita Prefecture from 2007 to 2014.

RESULTS

In 2007-2014, a total of 2527 esophageal cancer patients were registered in the system. Among these, only 43 (1.8%) had adenocarcinoma. However, the number of adenocarcinoma patients gradually increased from 1 case in 2007 to 14 cases in 2014. Consequently, the percentage of adenocarcinoma cases showed a significant increase from 0.66% in the first 4 years of the study period to 2.5% in the latter 4 years of the study period (P < 0.01).

CONCLUSIONS

The latest hospital-based registration data for 2007-2014 suggest that the incidence of esophageal adenocarcinoma may have begun to increase in Akita Prefecture; this may reflect recent trends in other parts of Japan.

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.

Contemporary migration patterns in the prevalence of Helicobacter pylori infection: A systematic review

BACKGROUND

A rapid growth in the number of international migrants over the past years has occurred with most traveling to more affluent settings. As Helicobacter pylori infects over half of the adult population and its prevalence is higher in developing countries, understanding the prevalence of infection in migrants can provide insight into future trends in the burden and management of infection. We aimed to describe the prevalence of H. pylori among migrants through a systematic literature review.

METHODS

We searched PubMed^® from inception to September 2015 to identify studies reporting the prevalence of H. pylori in international migrants according to country of birth for first-generation, and country of birth and parents' nationality for successive generations. Comparable data from origin and destination populations were obtained from the same studies or, when not present, from a previous systematic review on H. pylori worldwide.

RESULTS

A total of 28 eligible studies were identified with data for 29 origin and 12 destination countries. Two studies that evaluated refugees presented prevalences of infection higher than both the origin and destination countries. Otherwise, the prevalences among migrants were generally similar or below that of the origin and higher than the destination. Second- or more generation had lower prevalences compared to first-generation migrants.

CONCLUSIONS

Our study findings are consistent with what would be expected based on the prevalence of H. pylori worldwide. The results of this review show that migrants are particularly at risk of infection and help to identify gaps in the knowledge of migrants' prevalence of infection globally.

Azithromycin and risk of COPD exacerbations in patients with and without Helicobacter pylori

BACKGROUND

Helicobacter pylori (HP) infection is associated with reduced lung function and systemic inflammation in chronic obstructive pulmonary disease (COPD) patients. Azithromycin (AZ) is active against HP and reduces the risk of COPD exacerbation. We determined whether HP infection status modifies the effects of AZ in COPD patients.

METHODS

Plasma samples from 1018 subjects with COPD who participated in the Macrolide Azithromycin (MACRO) in COPD Study were used to determine the HP infection status at baseline and 12 months of follow-up using a serologic assay. Based on HP infection status and randomization to either AZ or placebo (PL), the subjects were divided into 4 groups: HP+/AZ, HP-/AZ, HP+/PL, and HP-/PL. Time to first exacerbation was compared across the 4 groups using Kaplan-Meier survival analysis and a Cox proportional hazards model. The rates of exacerbation were compared using both the Kruskal-Wallis test and negative binomial analysis. Blood biomarkers at enrolment and at follow-up visits 3, 12, and 13 (1 month after treatment was stopped) months were measured.

RESULTS

One hundred eighty one (17.8%) patients were seropositive to HP. Non-Caucasian participants were nearly three times more likely to be HP seropositive than Caucasian participants (37.4% vs 13.6%; p < 0.001). The median time to first exacerbation was significantly different across the four groups (p = 0.001) with the longest time in the HP+/AZ group (11.2 months, 95% CI; 8.4-12.5+) followed by the HP-/AZ group (8.0 months, 95% CI; 6.7-9.7). Hazard ratio (HR) for exacerbations was lowest in the HP+/AZ group after adjustment for age, sex, smoking status, ethnicity, history of peptic ulcer, dyspnea, previous hospital admission, GOLD grade of severity, and forced vital capacity (HR, 0.612; 95% CI, 0.442-0.846 vs HR, 0.789; 95% CI, 0.663-0.938 in the HP-/AZ group). Circulating levels of soluble tumor necrosis factor receptor-75 were reduced only in the HP+/AZ group after 3 months of AZ treatment (-0.87 ± 0.31 μg/L; p = 0.002); levels returned to baseline after discontinuing AZ.

CONCLUSIONS

AZ is effective in preventing COPD exacerbations in patients with HP seropositivity, possibly by modulating TNF pathways related to HP infection.

Value of the "Test & Treat" Strategy for Uninvestigated Dyspepsia at Low Prevalence Rates of Helicobacter pylori in the Population

BACKGROUND AND AIM

In populations with a low prevalence rate of Helicobacter pylori (H. pylori) infection from Western countries, guidelines for the management of uninvestigated dyspepsia generally recommend that the "test and treat" strategy should be avoided in favor of empiric proton-pump inhibitor therapy in younger patients (on average < 50 years of age) without alarm symptoms and signs. The prevalence of H. pylori infection has fallen from about 30% to about 10% in Sweden and other countries. We aimed to explore whether the rationale for test and treat is relevant in contemporary clinical practice.

MATERIALS AND METHODS

In settings with an infection rate in the adult population of 30% and 10%, we modeled the positive and negative predictive values for indirect (nonendoscopy) tests on current H. pylori infection with a presumed sensitivity and specificity of 95%. We then calculated the difference in false-negative and false-positive test outcome, and eradication prescription rates in the two scenarios.

RESULTS

While the positive predictive value for the test decreased from 0.89 to 0.68 when the prevalence of H. pylori fell from 30% to 10%, there were only 1% more false-negative tests and 1% less false-positive tests. The eradication prescription rate would decrease by 18% with a 10% prevalence rate.

CONCLUSION

The recommendation to stop applying "test and treat" at lower prevalence rates of H. pylori should be reconsidered. The test and treat strategy is the preferred approach for most patients who present with dyspepsia.

Gastric Helicobacter pylori Infection Affects Local and Distant Microbial Populations and Host Responses

Helicobacter pylori is a late-in-life human pathogen with potential early-life benefits. Although H. pylori is disappearing from the human population, little is known about the influence of H. pylori on the host's microbiota and immunity. Studying the interactions of H. pylori with murine hosts over 6 months, we found stable colonization accompanied by gastric histologic and antibody responses. Analysis of gastric and pulmonary tissues revealed increased expression of multiple immune response genes, conserved across mice and over time in the stomach and more transiently in the lungs. Moreover, H. pylori infection led to significantly different population structures in both the gastric and intestinal microbiota. These studies indicate that H. pylori influences the microbiota and host immune responses not only locally in the stomach, but distantly as well, affecting important target organs.

Towards a healthy stomach? Helicobacter pylori prevalence has dramatically decreased over 23 years in adults in a Swedish community

BACKGROUND

In Western countries the prevalence of Helicobacter pylori (H. pylori) infection may be declining but there is a lack of recent longitudinal population studies. We evaluated the changing epidemiology over a 23-year period in Sweden.

MATERIALS AND METHODS

In 1989, the validated Abdominal Symptom Questionnaire (ASQ) was mailed to a random sample of inhabitants (ages 22-80 years) in a Swedish community, and 1097 (87%) responded. H. pylori serology was analysed in a representative subsample (n = 145). Twenty-three years later, the ASQ was mailed again using similar selection criteria, and 388 out of 1036 responders had an upper endoscopy with assessment of H. pylori and corpus atrophy status.

RESULTS

The prevalence of positive H. pylori serology decreased from 37.9% (1989) to 15.8% (2012), corresponding to a decrease in odds of 75% per decade (odds ratio (OR): 0.25; 95% confidence interval (CI): 0.11-0.59, p = 0.001) independent of age, gender, body mass index (BMI) and level of education, with a pattern consistent with a birth cohort effect. The prevalence increased with increasing age (p = 0.001). The prevalence of H. pylori on histology in 2012 was 11.4% (95% CI 8.6-15.0). The prevalence of corpus atrophy on serology and/or histology in 2012 was 3.2% (95% CI 1.8-5.5); all cases were ≥57 years old.

CONCLUSION

The stomach is healthier in 2012 compared with 1989. H. pylori prevalence in adults has decreased over the last two decades to a level where clinical management might be affected.

Low prevalence and incidence of Helicobacter pylori infection in children: a population-based study in Japan

BACKGROUND

Infection of Helicobacter pylori mainly occurs in childhood. In Japan, incidence of gastric cancer is still high in the senior citizen population, but little is known about the current H. pylori infection status among children or their family members.

METHODS

As a population-based study, the prevalence of H. pylori infection and change in infection status over a 1-year interval in children were determined. Family members of some participants were also invited to participate in the study to determine their infection status. All children of specific ages attending 16 schools in Sasayama, Hyogo Prefecture, were invited to participate. H. pylori infection was determined by the stool antigen test and diagnosis confirmed by polymerase chain reaction and the urea breath test.

RESULTS

Helicobacter pylori prevalence was 1.9% among 689 children aged 0-8 years in 2010 and 1.8% among 835 children aged 0-11 in 2011. No feco-conversion was observed in 430 children aged 0-8 years (170 were aged 0-4 years) who provided follow-up stool samples after 1 year. The prevalence of infection was 6% (2 of 33) and 38% (6 of 16) in mothers of negative and positive probands (p = .04), respectively, and 12% (3 of 25) and 50% (8 of 16) (p = .01), respectively, in fathers.

CONCLUSION

Helicobacter pylori prevalence in Japanese children is approximately 1.8%, which is much lower than that reported in Japanese adults. New infection may be rare. Parent-to-child infection is thought to be the main infection route of the infrequent infection for children in Japan.

Evaluating the potential for a Helicobacter pylori drinking water guideline

Helicobacter pylori is a microaerophilic, gram-negative bacterium that is linked to adverse health effects including ulcers and gastrointestinal cancers. The goal of this analysis is to develop the necessary inputs for a quantitative microbial risk assessment (QMRA) needed to develop a potential guideline for drinking water at the point of ingestion (e.g., a maximum contaminant level, or MCL) that would be protective of human health to an acceptable level of risk while considering sources of uncertainty. Using infection and gastric cancer as two discrete endpoints, and calculating dose-response relationships from experimental data on humans and monkeys, we perform both a forward and reverse risk assessment to determine the risk from current reported surface water concentrations of H. pylori and an acceptable concentration of H. pylori at the point of ingestion. This approach represents a synthesis of available information on human exposure to H. pylori via drinking water. A lifetime risk of cancer model suggests that a MCL be set at <1 organism/L given a 5-log removal treatment because we cannot exclude the possibility that current levels of H. pylori in environmental source waters pose a potential public health risk. Research gaps include pathogen occurrence in source and finished water, treatment removal rates, and determination of H. pylori risks from other water sources such as groundwater and recreational water.

Helicobacter pylori seropositivities and risk of pancreatic carcinoma

BACKGROUND

Pathophysiologic actions of Helicobacter pylori colonization on gastric acidity have been hypothesized to modulate the effect of pancreatic carcinogens, through CagA-negative organism strain type, hyperchlorhydria and increased risk of pancreatic cancer, or CagA-positive strain, hypochlorhydria and decreased risk of pancreatic cancer. We aimed to determine H. pylori strain-specific associations with pancreatic cancer in a population in which colonization by CagA-positive strains is common.

METHODS

We carried out a large population-based case-control study of pancreatic carcinoma in Shanghai, China. Venipuncture specimens were obtained from a representative sample of 761 case patients and 794 randomly selected control subjects matched by category of age and gender. Antibody seropositivity for H. pylori and its virulence protein CagA were determined by commercial enzyme-linked immunosorbent IgG assays.

RESULTS

Compared with individuals seronegative for both H. pylori and CagA, decreased pancreas-cancer risk was seen for CagA seropositivity [adjusted OR, 0.68; 95% confidence interval (CI), 0.54-0.84], whereas some increased risk was suggested for CagA-negative H. pylori seropositivity (OR, 1.28; 95% CI, 0.76-2.13). No risk interactions were observed between CagA seropositivity and gender, cigarette smoking, or age-21 body mass index.

CONCLUSIONS

Similar to what has been seen in animal models, our results provide suggestive evidence in humans for the involvement of gastric acidity, through its bidirectional modification according to colonization by H. pylori CagA strain type, in the risk of pancreatic carcinoma.

IMPACT

H. pylori colonization may have diverse effects on cancer risk, depending on the organism strain type as well as on the particular cancer site.

Rate ofHelicobacter pyloriInfection in Children and Clonality of Taiwan Strains

The infection rate of Helicobacter pylori in children from < 1 to 17 years old was investigated. Three techniques, namely culture, CLO test, and PCR, were employed to check the presence or absence of the organism in the antrum of the stomach. Several PCR positives without viable cultures were observed in babies of less than one year old. On the other hand, only two viable cultures were obtained from toddlers of less than two years old. The percentage of positive cultures steadily increased from 8% (3 of 42 cases) in the 0-4 years old age group to 32% (32 of 99 cases) in the 13-17 years old age group. A steady increase also was observed in the result of the CLO test. In PCR, the percentage of positives was greatly higher than that seen with the culture or CLO test. The rate of PCR positives also showed an increase with age but of a much slower rate. The overall infection rate in 295 children was 22% (64 of 295 cases) positive with culture and 76% (225 of 295 cases) with PCR, in contrast to 85% (40 of 49 cases) and 92% (43 of 47 cases), respectively, in adults. The urease activity of the H. pylori derived from children was much lower than that derived from adults (P < 0.001). Taken together, these results suggest that a child might be repeatedly infected and some infecting strains eventually might obtain a steady infection, perhaps by a strain of higher virulence such as higher urease activity. The base variations in the nucleotide sequences did not correlate to the varied urease activities or to the age of the child. The sequences, however, indicated that there were two types of strains. The strains in Taiwan appeared to be derived from the French type strain and not the English type strain. The amino acid sequences of the ureA and the phylogenetic relationship of the 29 strains indicated that the strains in Taiwan are rapidly evolving into a unique clone.

Seroconversion rates of Helicobacter pylori infection in Korean adults

BACKGROUND

Studies on seroconversion and its reversion rate in Korean adults with Helicobacter pylori infection are very rare. The purpose of this study was to evaluate the overall seroprevalence, seroconversion rate, and seroreversion rate of H. pylori infection in an adult population.

MATERIALS AND METHODS

We performed this retrospective cohort study on healthy adults who had visited our health screening center at Asan Medical Center more than twice between January 2000 and December 2010. We reviewed the anti- H. pylori Ab IgG profiles of the enrolled people and their family members and the results of esophagogastroduodenoscopies and a self-reported questionnaire.

RESULTS

A total of 67,212 people were enrolled in this study. The mean follow-up duration was 4.6 years, and each participant visited the center for a mean of 3.8 visits. The overall proportions of participants demonstrating persistent seropositivity, persistent seronegativity, seroconversion, and seroreversion were 53.1%, 32.5%, 4.3%, and 10.1%, respectively. The annual seroconversion rate was 2.79%. The annual crude and spontaneous seroreversion rates of the entire study population were 3.64% and 2.42%, respectively. According to multivariate logistic regression, old age (HR = 1.015), smoking (HR = 1.216), alcohol consumption more than four times per week (HR = 1.263), marriage (HR = 2.735), and living with H. pylori-infected family members (HR = 1.525) were identified as statistically significant risk factors associated with seroconversion.

CONCLUSION

The annual seroconversion rate was 2.79% in our study population. Marriage and living with H. pylori-infected family members were important risk factors affecting seroconversion in our adult population.

Serologic host response to Helicobacter pylori and Campylobacter jejuni in socially housed Rhesus macaques (Macaca mulatta)

Background

Helicobacter pylori are successful colonizers of the human gastric mucosa. Colonization increases the risk of peptic ulcer disease and adenocarcinoma. However, potential benefits of H. pylori colonization include protection against early-onset asthma and against gastrointestinal infections. Campylobacter jejuni are a leading cause of bacterial diarrhea and complications include Guillain-Barré syndrome. Here, we describe the development of reliable serological assays to detect antibodies against those two bacteria in Rhesus macaques and investigated their distribution within a social group of monkeys.

Methods

Two cohorts of monkeys were analyzed. The first cohort consisted of 30 monkeys and was used to establish an enzyme-linked immunosorbent assay (ELISA) for H. pylori antibodies detection. To evaluate colonization of those macaques, stomach biopsies were collected and analyzed for the presence of H. pylori by histology and culture. C. jejuni ELISAs were established using human serum with known C. jejuni antibody status. Next, plasma samples of the 89 macaques (Cohort 2) were assayed for antibodies and then statistically analyzed.

Results

An H. pylori IgG ELISA, which was 100% specific and 93% sensitive, was established. In contrast, the IgA ELISA was only 82% specific and 61% sensitive. The CagA IgG assay was 100% sensitive and 61% of the macaques were positive. In cohort 2, 62% macaques were H. pylori sero-positive and 52% were CagA positive. The prevalence of H. pylori IgG and CagA IgG increased with monkey age as described for humans. Of the 89 macaques 52% showed IgG against C. jejuni but in contrast to H. pylori, the sero-prevalence was not associated with increasing age. However, there was a drop in the IgG (but not in IgA) mean values between infant and juvenile macaques, similar to trends described in humans.

Conclusions

Rhesus macaques have widespread exposure to H. pylori and C. jejuni, reflecting their social conditions and implying that Rhesus macaques might provide a model to study effects of these two important human mucosal bacteria on a population.

Non-invasive genotyping of Helicobacter pylori cagA, vacA, and hopQ from asymptomatic children

BACKGROUND

Helicobacter pylori infection is usually acquired in childhood, but little is known about its natural history in asymptomatic children, primarily due to the paucity of non-invasive diagnostic methods. H. pylori strains harboring cagA and specific alleles of hopQ and vacA are associated with increased risk for gastric cancer. Many studies of H. pylori virulence markers in children have the bias that symptomatic subjects are selected for endoscopy, and these children may harbor the most virulent strains. Our aim is to genotype cagA, hopQ, and vacA alleles in stool DNA samples of healthy Colombian children residing in an area with high incidence of gastric cancer, to avoid selection bias resulting from endoscopy.

METHODS

H. pylori status of 86 asymptomatic children was assessed by (13) C-urea breath test (UBT) and PCR. H. pylori 16S rRNA, cagA, hopQ, and vacA genes were amplified from stool DNA samples and sequenced.

RESULTS

UBT was positive in 69 (80.2%) of 86 children; in stool DNA analysis, 78.3% were positive by 16S rRNA PCR. cagA, vacA, and hopQ were detected in 66.1%, 84.6%, and 72.3% of stool DNA samples from 16S rRNA-positive children. Of the children's DNA samples, which revealed vacA and hopQ alleles, 91.7% showed vacA s1 and 73.7% showed type I hopQ. Type I hopQ alleles were associated with cagA positivity and vacA s1 genotypes (p < 0.0001).

CONCLUSIONS

Using stool DNA samples, virulence markers of H. pylori were successfully genotyped in a high percentage of the asymptomatic infected children, revealing a high prevalence of genotypes associated with virulence. Type I hopQ alleles were associated with the presence of cagA and the vacA s1 genotype.

Natural history of Helicobacter pylori infection in childhood: eight-year follow-up cohort study in an urban community in northeast of Brazil

BACKGROUND

Helicobacter pylori infection is acquired predominantly in childhood. There is also evidence that children loss the infection. Therefore, factors that account for children remain infected need to be investigated because once established the infection persists throughout the life unless treated.

METHODS

This study aimed to evaluate the H. pylori infection in children of a low-income community at baseline and 8years later to determine the predictor factors linked to the maintenance, acquisition, and loss of the infection using regression models of generalized estimating equations. H. pylori status was determined by (13) C-urea breath test.

RESULTS

Data from 37.7% (133/353) of the children were available. No difference between the characteristics of the included and nonincluded children was observed. The prevalence of infection increased from 53.4 to 64.7%. Thirty-nine children (29.3%) remained noninfected, 47.4% remained infected, 17.3% became infected, and 6.0% lost the infection. Factors associated with to remain infected compared with to remain noninfected included the age, increased number of children in the household, and the use of well water instead of municipal water. The acquisition of the infection was associated with the male gender.

CONCLUSION

Factors linked to remain and to gain H. pylori infection in a poor region were increased number of children in the household and the male gender. Also, the acquisition rates were higher than the loss rates, which lead to an increase in the infection prevalence with age.

Secular trends in Helicobacter pylori seroprevalence in adults in the United States: evidence for sustained race/ethnic disparities

Helicobacter pylori seroprevalence levels in US adults participating in the continuous National Health and Nutrition Examination Survey (1999-2000) increased with age in all racial/ethnic groups, with significantly higher age-standardized levels in Mexican Americans (64.0%, 95% confidence interval (CI): 58.8, 69.2) and non-Hispanic blacks (52.0%, 95% CI: 48.3, 55.7) compared with non-Hispanic whites (21.2%, 95% CI: 19.1, 23.2). Although seroprevalence levels remained similar to those found in National Health and Nutrition Examination Surveys from 1988 to 1991 among non-Hispanic blacks and Mexican Americans, they were significantly lower in non-Hispanic whites, especially at older ages. The factors driving the decline in H. pylori seroprevalence appear to be acting preferentially on the non-Hispanic white population.

Prevalence and determinants of Helicobacter pylori sero-positivity in the Australian adult community

BACKGROUND AND AIM

  To estimate the sero-prevalence of Helicobacter Pylori infection in the Australian adult population and identify determinants.

METHODS

  We analyzed serum samples and questionnaire data from 1355 community controls who participated in a nationwide case-control study of esophageal cancer in Australia between 2002 and 2005. We estimated the prevalence ratio and 95% confidence interval using log binomial regression models.

RESULTS

  The age and sex standardized sero-prevalence of H. pylori was 15.5%. The prevalence of infection varied significantly with age, ranging from 5% (< 40 years) to 32% (≥ 70 years). H. pylori infection was significantly higher among those born overseas (prevalence ratio [PR] 1.63; 95% confidence interval [CI] 1.34-1.98) compared with those born in Australia or New Zealand. H. pylori sero-prevalence was 23% higher among participants living in the lowest quartile of socio-economic areas (PR 0.77; 95%CI 0.59-0.99 for Q4 compared with Q1). H pylori serostatus was significantly inversely associated with university education (PR 0.56; 95%CI 0.38-0.83), frequent reflux symptoms (PR 0.62; 95%CI 0.42-0.91), use of proton pump inhibitor (PR 0.69; 95%CI 0.48-0.98) and use of medications for gut spasms (PR 0.48; 95%CI 0.25-0.93). H. pylori serostatus was not associated with body mass index, smoking, alcohol or physical activity.

CONCLUSIONS

  The prevalence of H. pylori infection in Australian adults is lower than other developed countries. H. pylori infection is most common among those living in the areas of socio-economic disadvantage or who were born overseas.

Apparent incidence of Helicobacter pylori in adulthood: to what extent do new infections reflect misclassification?

BACKGROUND

Helicobacter pylori infection is a key risk factor for a variety of gastrointestinal diseases. About half of the world population is infected. Most infections are acquired early in childhood, but the occurrence of new infections among adults has also been suggested.

METHODS

We review epidemiological studies providing estimates of incidence of H. pylori infection among adults and evaluate to what extent incidence estimates might have been affected by measurement error of infection status.

RESULTS

Thirty-two studies could be included in the review. Annual incidence was lower than 1.0 % in 17 studies; no correlation between length of follow-up and cumulative incidence was observed. Apparent cumulative incidences of the magnitudes observed in most studies would be expected, because of less than perfect sensitivity and specificity of the diagnostic tests, even in the absence of any true new infections. CONCLUSION/IMPACT: Apparent incidence rates of H. pylori infection among adults in Western populations should be interpreted with utmost caution.

Serum level of pepsinogen significantly associated with gastric distress induced by amino-bisphosphonates

To elucidate whether serum levels of pepsinogens are associated with the occurrence of gastrointestinal adverse events induced by amino-bisphosphonates (amino-BP), the serum levels of pepsinogen were measured in amino-BP users. Our results indicate that measurement of pepsinogen I is useful in predicting gastric distress induced by amino-BP in osteoporosis.

INTRODUCTION

To elucidate whether serum levels of pepsinogens are associated with the occurrence of gastrointestinal adverse events induced by amino-BP, the serum levels of pepsinogen I and II were measured in amino-BP users.

METHODS

When the patients complained of gastric distress symptoms during the first 6 months after amino-BP use resulting in discontinuation of the drug, endoscopical examinations were performed to assess whether gastric lesions were present. A total of 223 amino-BP users were enrolled in the study, of which 47 patients refused to take the drug due to gastric distress symptoms. The remaining 176 patients did not complain of any gastric distress.

RESULTS

Among 47 patients, eight patients showed obvious gastric lesions such as gastric or duodenal ulcers and acute gastric mucosal lesions in the endoscopical examination. The remaining 39 patients did not show any gastric lesions. The possible confounding factors, such as a Helicobactor pylori infection or concurrent use of ulcerogenic agents, did cause not affect gastric distress in amino-BP users. The serum pepsinogen I level was significantly associated with severity of the gastric lesion 46.8 ± 27.7, 60.8 ± 32.4, and 103.4 ± 49.2 ng/ml for patients without any gastric distress, with gastric distress accompanied no gastric lesions, and with gastric distress accompanied gastric lesions, respectively.

CONCLUSIONS

ROC analysis revealed that the cutoff value of pepsinogen I for expectation of gastric regions was 76.8 ng/ml. The results clearly indicate that measurement of pepsinogen I may be useful in predicting gastric distress induced by amino-BP in osteoporosis.

The relationship between Helicobacter pylori infection and Alzheimer's disease in Japan

Although two studies have indicated a possible link between Alzheimer's disease (AD) and Helicobacter pylori (H. pylori) infection, these were reported from Europe, where the prevalence of H. pylori infection is not very high. In this study, the prevalence of H. pylori infection was examined in AD patients in Japan, where there is a high prevalence of H. pylori. Consecutive patients referred to the Memory and Dementia Outpatient Clinic from August 2002 to March 2009 were studied. H. pylori infection status was determined by measuring urinary levels of anti-H. pylori antibody (RAPIRUN(®)). Multiple stepwise logistic regression analyses were used to examine the associations of AD with the main predictor variables. Of the 917 patients who visited the clinic, 385 were diagnosed as having AD. Ninety-seven patients did not have dementia and were considered controls. On univariate analysis, average age and the proportion of males were significantly higher in AD patients than in controls. There was no difference in the prevalence of H. pylori infection between patients with AD and controls (62.0% vs. 59.7%, p = 0.67, crude odds ratio (OR), 1.10). Multiple logistic regression analysis showed that older age and male sex, but not H. pylori status, were significantly associated with AD (p < 0.001, p = 0.01, p = 0.83, respectively). The prevalence of H. pylori infection did not differ between AD patients and controls among Japanese subjects. The high prevalence of H. pylori in controls may contribute to the discrepancy with previous reports.

Helicobacter pylori infection among a pediatric population with sickle cell disease

OBJECTIVES

Recurrent abdominal pain (RAP) is a common presenting symptom in children with sickle cell disease (SCD). This may be as a result of complications of the disease, surgical problems, or Helicobacter pylori gastritis. The prevalence of H pylori infection in SCD children is not known. This study aimed to determine the prevalence and association of H pylori infection with RAP in SCD children.

METHODS

This was a prospective case-control study conducted at the Lagos State University Teaching Hospital, Nigeria, involving SCD children (subject, n = 118) and non-SCD children (control, n = 118) matched for age, sex, and socioeconomic status. Seroprevalence status of the children was determined by measuring immunoglobulin G antibodies against H pylori using enzyme-linked immunosorbent assay that had been validated for pediatric use.

RESULTS

The overall prevalence of H pylori infection was 155 of 236 (SCD, 67.8%; non-SCD, 63.6%; OR, 1.1; 95% CI, 0.89-1.28; p = .493). The prevalence increased with age in both SCD and non-SCD children and was significantly highest at the age of 6 to 10 years (p < .001 in each case). H pylori infection was significantly associated with socioeconomic status of the parents (OR, 4.25; 95% CI, 1.49-12.1; p = .004) but not significantly associated with RAP in SCD children (OR, 1.21: 95% CI, 0.55-2.66; p = .632).

CONCLUSIONS

Prevalence of H pylori infection is high in SCD and non-SCD children in Lagos, Nigeria. There was no significant association between H pylori infection and recurrent abdominal pain in SCD children.

Recent knowledge of the relationship between Helicobacter pylori and gastric cancer and recent progress of gastroendoscopic diagnosis and treatment for gastric cancer

Gastric cancer is a multi-step process and multi-factorial disease. However, Helicobacter pylori plays the most important role in gastric carcinogenesis because most gastric cancers including both intestinal type and diffuse type arise from mucosa infected by H. pylori. The relationship between H. pylori infection and gastric cancer has been proved in epidemiological studies, animal experiments with Mongolian gerbils, and clinical prospective studies. Significant preventive effect of H. pylori eradication was reported in Japanese randomized study for secondary gastric cancer after endoscopic resection of primary gastric cancer and meta-analysis of randomized studies. The Japanese Society for Helicobacter Research has published a guideline recommending that H. pylori infection should be treated by eradication therapy to suppress the incidence of gastric cancer. The development of endoscopic technology has advanced the diagnosis and treatment of gastric cancer. In the diagnosis of gastric cancer, image enhancement endoscopy including magnifying observation with narrow-band imaging system and microscopic magnifying observation opens the possibility of optical biopsy. Endoscopic resection for early stage of gastric cancer has been established as proper treatment of early gastric cancer. Recently endoscopic submucosal dissection had made en bloc resection possible for mucosal cancers >2 cm in diameter. Because of endoscopic submucosal dissection, endoscopic resection is indicated in a greater number of cases. Although the use of endoscopic treatment for gastric cancer has been increasing steadily, long-term outcome data is necessary.

Helicobacter pylori in apparently healthy children aged 0-12 years in urban Kampala, Uganda: a community-based cross sectional survey

Background

Helicobacter pylori is one of the most common causes of bacterial infection in human beings. Studies have showed a high prevalence of Helicobacter pylori among people in low-income countries and colonization early in life. A monoclonal antigen test, performed on faeces, HpSA^®ImmunoCardSTAT, has a high sensitivity, specificity and accuracy and the faecal test can be performed in all ages, also in resource-limited settings. The main objective of this study was to determine the prevalence and factors associated with Helicobacter pylori colonization in apparently healthy children aged 0-12 years in urban Kampala, Uganda.

Method

We tested 427 apparently healthy children, age 0-12 years (211 males, 216 females), in a cross sectional survey for Helicobacter pylori colonization using HpSA ^®ImmunoCardSTAT. A short standardized interview with socio-demographic information and medical history was used to assess risk factors.

Results

The overall prevalence of Helicobacter pylori in the 427 children was 44.3% (189 out of 427). Early colonization was common, 28.7%, in children younger than 1 year of age. The age specific rates were 46.0% in children age 1- < 3 years, 51.7% in children age 3- < 6 years, 54.8% in children age 6- < 9 years and 40.0% in children age 9- < 12 years. There was a significant difference in prevalence by gender; female 38.5% versus male 49.8% and by type of housing; permanent house 38.5% versus semi-permanent house 48.6%. Congestive living and education level of the female caretaker showed a clear trend for a difference in prevalence. Factors independently associated with Helicobacter pylori colonization included: drugs taken last three months, using a pit latrine, sources of drinking water and wealth index.

Conclusion

The prevalence of Helicobacter pylori colonization among urban Ugandan children is high at an early age and increases with age. The impact of Helicobacter pylori colonization on children's health in Uganda needs to be further clarified.

Helicobacter pylori in alcohol induced acute pancreatitis

BACKGROUND AND AIMS

The objective of this study was to measure the association of Helicobacter pylori infection with alcoholic acute pancreatitis.

MATERIAL AND METHODS

This study comprised of 50 patients with their first alcoholic pancreatitis and 50 alcoholic controls with no history of pancreatitis but similar alcohol use recruited from an alcohol rehabilitation center. Helicobacter infection was measured using Enzygnost EIA IgG-test. Complications and length of hospital stay were also recorded in patients with alcoholic pancreatitis.

RESULTS

The seroprevalence of Helicobacter pylori was 10/50 (20%) in the pancreatitis group and 15/50 (30%) in the control group (p = NS). The median length of hospital stay of pancreatitis patients was 7 days, 11 days for those tested positive (range 6-25) and 6 days for those tested negative (range 3-47) for Helicobacter pylori, p = 0.013. As determined with the Atlanta criteria, seropositive patients tended to have more often severe pancreatitis, 4/10 (40%) vs. 6/40 (15%), OR 3.78 (95% CI 0.815-17.52), p = 0.097.

CONCLUSIONS

This study suggests that Helicobacter pylori infection is not associated clinically significantly with the development of alcoholic pancreatitis. However, Helicobacter pylori infection may be associated with longer hospital stay due to more severe disease, which needs to be studied in a larger series of patients.

Population-based strategies for Helicobacter pylori-associated disease management: a Japanese perspective

The prevalence of Helicobacter pylori infection is decreasing gradually in Japan mainly owing to an improvement in sanitary conditions. The guidelines for H. pylori management by the Japanese Society for Helicobacter Research, initially established in 2000 and revised in 2003, were revised dramatically in January 2009. The new guidelines accepted the use of new drugs and recommended trying the second-line eradication regimen. Moreover, the revised guidelines reflected the recent knowledge in Japan that metachronous gastric cancer prevalance is decreased significantly by the eradication of H. pylori infection. The Japanese Society for Helicobacter Research proposed that the cure of H. pylori infection should be presupposed to prevent gastric cancer from active gastritis universally developed in the infected subjects. Overall, the most important and dramatic revision is that all infected people are recommended to receive eradication therapy irrespective of the clinical outcomes in the Japanese population.

Guidelines for the management of Helicobacter pylori infection in Japan: 2009 revised edition

BACKGROUND

Over the past few years, the profile of Helicobacter pylori infection has changed in Japan. In particular, the relationship between H. pylori and gastric cancer has been demonstrated more clearly. Accordingly, the committee of the Japanese Society for Helicobacter Research has revised the guidelines for diagnosis and treatment of H. pylori infection in Japan.

MATERIALS AND METHODS

Four meetings of guidelines preparation committee were held from July 2007 to December 2008. In the new guidelines, recommendations for treatment have been classified into five grades according to the Minds Recommendation Grades, while the level of evidence has been classified into six grades. The Japanese national health insurance system was not taken into consideration when preparing these guidelines.

RESULTS

Helicobacter pylori eradication therapy achieved a Grade A recommendation, being useful for the treatment of gastric or duodenal ulcer, for the treatment and prevention of H. pylori-associated diseases such as gastric cancer, and for inhibiting the spread of H. pylori infection. Levels of evidence were determined for each disease associated with H. pylori infection. For the diagnosis of H. pylori infection, measurement of H. pylori antigen in the feces was added to the tests not requiring biopsy. One week of proton-pump inhibitor-based triple therapy (including amoxicillin and metronidazole) was recommended as second-line therapy after failure of first-line eradication therapy.

CONCLUSION

The revised Japanese guidelines for H. pylori are based on scientific evidence and avoid the administrative restraints that applied to earlier versions.

The source of Helicobacter pylori infection in the neonatal period

AIMS

To investigate the transmission of Helicobacter pylori in the perinatal period.

METHODS

H. pylori status of 180 women was preliminarily screened by serology and stool antigen test (SAT) within the fourth day after delivery and a positive value was confirmed by (13)C-urea breath test. Infants were analyzed by SAT at 1, 6, 12 and 18 months of age. H. pylori status was also investigated in the medical and paramedical staff of the Neonatology Unit.

RESULTS

H. pylori infection was found in 34.4% of the women. At the 1(st) month of age, 5 out of 172 newborns (2.9%) were H. pylori positive by SAT. Three out of the five positive infants were born to H. pylori non-infected mothers. Formula feeding (P=0.02) and admission in intermediate-risk neonatal unit (P=0.01) were significantly related to a positive H. pylori result. Medical and paramedical staff of the neonatology unit was found H. pylori positive in 34.8% of cases. All five H. pylori positive children spontaneously cleared the infection.

CONCLUSIONS

Perinatal H. pylori SAT positive status is low in our area, and it may be found both in infants from infected or non-infected mothers. Formula feeding and admission in intermediate-risk neonatal unit appear to be related with H. pylori infection.

Helicobacter pylori infection in developing countries: the burden for how long?

Approximately 50% (over 3 billion) of the world populations are known to be infected with Helicobacter pylori , mainly in the developing countries . Among those, hundreds of millions of people develop peptic ulceration during their lifetime and still tens of millions might progress to gastric cancer. Possible modes of H. pylori transmission generally described are through direct contact between family members and also through contaminated water and food. Because the high prevalence of infection occurs mainly in developing countries and because the test-and-treat strategy puts a huge economic burden on many of these countries, it is time to take an immediate action toward this bacterial infection and adopt a strategy to prevent it. To address this issue, an updated prevalence of infection, modes of transmission, economics of infection and preventative measures to block the infection process have been discussed.

Helicobacter pylori infection rate decreases in symptomatic children: a retrospective analysis of 13 years (1993-2005) from a gastroenterology clinic in West Virginia

BACKGROUND

The rate of Helicobacter pylori is decreasing in the developed countries, but few long-term studies are available from the United States. We retrospectively assessed the annual H. pylori infection rate in symptomatic children seen in our clinic over a 13-year study period.

STUDY

A retrospective analysis of all children who had histologic diagnosis of H. pylori infection between January 1993 and December 2005 in our pediatric gastroenterology clinic was performed. The annual infection rate and the overall infection rate were calculated.

RESULTS

A total of 1743 upper endoscopy reports were reviewed, of which 212 (12.1%) were diagnosed with H. pylori infection. A significant decrease in mean annual H. pylori infection rate was noted in the last 6 years of the study period (2000 to 2005), compared with the first 7 years (1993 to 1999) (18.2% vs. 7.3%, respectively; P=0.001).

CONCLUSIONS

The incidence of H. pylori infection in symptomatic children in our clinic is decreasing. A national multicenter study will be needed to assess whether this drop is a local phenomenon or a national trend.

Roles of gastric mucin-type O-glycans in the pathogenesis of Helicobacter pylori infection

Helicobacter pylori is a Gram-negative bacterium that infects over 50% of the world's population. This organism causes various gastric diseases such as chronic gastritis, peptic ulcer, and gastric cancer. H. pylori possesses lipopolysaccharides that share structural similarity to Lewis blood group antigens in gastric mucosa. Such antigenic mimicry could result in immune tolerance against antigens of this pathogen. On the other hand, H. pylori colonizes gastric mucosa by utilizing adhesins that bind Lewis blood group antigen-related carbohydrates expressed on gastric epithelial cells. After colonization, H. pylori induces acute inflammatory responses mainly by neutrophils. This acute phase is gradually replaced by a chronic inflammatory response. In chronic gastritis, lymphocytes infiltrate the lamina propria, and such infiltration is facilitated by the interaction between L-selectin on lymphocytes and peripheral lymph node addressin (PNAd), which contains 6-sulfo sialyl Lewis X-capped O-glycans, on high endothelial venule (HEV)-like vessels. H. pylori barely colonizes gland mucous cell-derived mucin where alpha1,4-GlcNAc-capped O-glycans exist. In vitro experiments show that alpha1,4-GlcNAc-capped O-glycans function as a natural antibiotic to inhibit H. pylori growth. These findings show that distinct sets of carbohydrates expressed in the stomach are closely associated with pathogenesis and prevention of H. pylori-related diseases, providing therapeutic potentialities based on specific carbohydrate modulation.

Acquisition of Helicobacter pylori infection in early childhood: independent contributions of infected mothers, fathers, and siblings

OBJECTIVES

Infected siblings, mothers, and fathers have all been suggested to be major sources for Helicobacter pylori acquisition among children, but few studies have addressed the potential role of various family members simultaneously.

METHODS

A systematic review was performed on studies investigating intrafamilial transmission of childhood H. pylori infection. Within the Ulm Birth Cohort Study, which consists of 1,066 healthy newborns, born between November 2000 and November 2001 and followed up to age 4, and their siblings and parents, the independent role of the infection status of parents and siblings in transmission of H. pylori among children at age 4 was assessed.

RESULTS

Among four studies reporting infected mothers and siblings as independent risk factors for childhood H. pylori infection, odds ratios (ORs) for childhood infection given an infected sibling decreased meaningfully after adjustment for maternal infection status. Within the Ulm Birth Cohort Study, the prevalence of infection was 3.0% among index children at age 4. In bivariate analyses, maternal, paternal, and sibling infection were all strongly and significantly related to infection of the child. However, after multivariate adjustment, only maternal infection persisted as the single strong and significant risk factor (OR 13.0, 95% confidence interval 3.0-55.2).

CONCLUSIONS

These patterns suggest that mutual control for H. pylori status of other family members is crucial for estimating the role of mothers, fathers, and siblings in the transmission of childhood H. pylori infection. In populations with low H. pylori prevalence the infected mother is likely to be the main source for childhood H. pylori infection.

Carbohydrate-dependent defense mechanisms against Helicobacter pylori infection

Helicobacter pylori is a Gram-negative bacterium that infects over 50% of the world's population. This organism causes various gastric diseases such as chronic gastritis, peptic ulcer, and gastric cancer. H. pylori possesses lipopolysaccharide, which shares structural similarity to Lewis blood group antigens in gastric mucosa. Such antigenic mimicry could result in immune tolerance against antigens of this pathogen. On the other hand, H. pylori colonize gastric mucosa by utilizing adhesins, which bind Lewis blood group antigen-related carbohydrates expressed on gastric epithelial cells. In chronic gastritis, lymphocytes infiltrate the lamina propria, and such infiltration is facilitated by 6-sulfo sialyl Lewis X-capped O-glycans, peripheral lymph node addressin (PNAd), on high endothelial venule (HEV)-like vessels. The number of HEV-like vessels increases as chronic inflammation progresses. Furthermore, PNAd formed on HEV-like vessels disappear once H. pylori is eradicated. These results indicate that PNAd plays an important role in H. pylori-associated inflammation. H. pylori barely colonizes gland mucous cell-derived mucin where alpha1,4-GlcNAc-capped O-glycans exist. In vitro experiments show that alpha1,4-GlcNAc-capped O-glycans function as a natural antibiotic to inhibit H. pylori growth. We recently identified cholesterol alpha-glucosyltransferase (CHLalphaGcT) using an expression cloning strategy and showed that this enzyme is specifically inhibited by mucin-type O-glycans like those present in deeper portions of the gastric mucosa. These findings show that a battery of carbohydrates expressed in the stomach is closely associated with pathogenesis and also prevention of H. pylori-related diseases.

Changes in the presence of urine Helicobacter pylori antibody in Japanese children in three different age groups

BACKGROUND

The rates of acquisition and spontaneous eradication of Helicobacter pylori infection in children has yet to be established. To determine these rates in children living in an urban region of Japan, the levels of urine H. pylori antibodies in children of three different age groups were measured.

METHODS

A urine-based enzyme-linked immunosorbent assay (ELISA) was used to detect H. pylori antibodies twice within a 12 month interval over 2 years in 452 healthy children living in Tokyo. The subjects were divided into three groups: ages 4, 7, and 10 years.

RESULTS

The prevalence of H. pylori infection was not different among the groups, being between 4.0% and 6.7%. The rate of turn to positivity for H. pylori infection was 1.5% per year and the rate of turn to negativity was 1.1%, but in the 10 year age group the rates were markedly lower than in the younger children.

CONCLUSION

The prevalence of H. pylori infection in Tokyo was 4.0-6.7% and was not different among 4, 7, and 10 year age groups.

Helicobacter pylori infection in pediatrics

During the last year, epidemiologic studies have shown that spontaneous clearance of Helicobacter pylori infection has a less significant role in countries with high prevalence and, in contrast to adults, there is no male predominance of H. pylori infection in children. Early acquisition of H. pylori may play a role in the development of recurrent abdominal pain in children less than 5 years of age. In this very young age group, the adequate performance of stool antigen test and (13)C urea-breath test demonstrated satisfactory sensitivity and specificity as non-invasive methods to diagnose H. pylori infection. In the current paper, the most relevant pediatric studies on H. pylori infection published between April 2006 and March 2007 are reviewed.

Dramatic changes in the prevalence of Helicobacter pylori infection during childhood: a 10-year follow-up study in Russia

BACKGROUND

The prevalence and rate of acquisition of Helicobacter pylori infection in children from developing countries is higher than in developed countries. This phenomenon has been related to differences in socioeconomic status, sanitation, and household hygiene. Russia is in the process of transforming from an underdeveloped to a developed country.

AIM

To examine the effect of recent improvements in standards of living on the prevalence of H pylori in Russian children.

PATIENTS AND METHODS

We conducted 2 cross-sectional studies among children in St Petersburg, Russia. The first study was conducted in 1995 and the second was conducted a decade later. H pylori status was evaluated by the same enzyme-linked immunoassay method for anti-H pylori immunoglobulin G. Demographic data were obtained from each individual, and socioeconomic class was assessed by the education level of the mother and family income.

RESULTS

In 1995 the overall prevalence of H pylori infection was 44%; 10 years later it had decreased to 13%. In both studies, the prevalence increased with age. In 1995 the prevalence was 30% among children younger than 5 years. A decade later the prevalence in the same age group was 2% (P = 0.001). The age-specific prevalence of H pylori infection increased significantly with age in both study periods. During 1995 the prevalence of the infection increased from 30% at age <5 years to 48% in the age group 15 to 19 years (P = 0.001). In the 2005 study the prevalence of the infection increased from 2% at age <5 years to 25% in the age group 15 to 19 years (P = 0.001). The crude and the age-adjusted odds ratio risk of infection in children showed an inverse correlation between the mothers' and fathers' educational levels and H pylori seropositivity (OR 1.8, 95% CI 1-3.2; P = 0.06). No associations were found between the prevalence of H pylori and any factor tested, including sex, type of dwelling, income, or the number of people living in the home.

CONCLUSIONS

Improvements in standards of living in Russia have resulted in a marked reduction in H pylori transmission. Different rates of acquisition of H pylori form the basis for the differences in prevalence of infection between and among populations. The change in the prevalence of H pylori within 10 years among the Russian population is an example of how sensitive H pylori acquisition is to improvement in standards of living. Increased use of anti-H pylori eradication therapy played an important role in the reduction of the prevalence of H pylori infection.

How labile is gastric infection with H pylori?

It is known that patients infected with H pylori can spontaneously become free from infection, and that the reverse change can occur. The time-scale of these conversions is expressed as percentages per year. Since they have been investigated in terms of serology, the changes are called sero-reversion and sero-conversion respectively. Using serological evidence to investigate these phenomena is open to the criticisms that positive serology can be present in the absence of all other evidence of infection, and that a time-lag of 6-12 mo or longer can occur between eradication of the infection and sero-reversion. Investigations using direct evidence of current infection are sparse. The few that exist suggest that some individuals can seroconvert or sero-revert within six to twelve weeks. If these findings are confirmed, it means that some patients have an ability that is variable in time to resist, or spontaneously recover from, H pylori infection. Evidence suggests that the deciding factor of susceptibility is the level of gastric secretion of acid.

Detection rate of Helicobacter pylori stool antigen in newborn infants and small children

AIMS

To investigate the prevalence of H. pylori antigen in the stools of Norwegian neonates and small children.

METHODS

A total of 249 children aged 0 days-3 years were tested for the presence of H. pylori antigen in feces using the HpSA immunoassay. For verification purposes, a selection of samples were analyzed with PCR targeting the 16 S rDNA Helicobacter gene.

RESULTS

H. pylori antigen in stool was detected in 52% (36/69) of the neonates, in 15% (7/46) of infants aged 7 days-1 month, and in 5% (7/134) of children aged 1 month-3 years. In neonates, H. pylori antigen detection was significantly associated with mode of delivery: 59% (30/51) with uncomplicated vaginal births were HpSA positive compared to only 10% (1/10) of infants delivered by cesarean section (P=0.02). Positive PCR results were found in 35% (9/26) of HpSA positive samples. Sequencing of PCR products revealed 97-100% homology with gene sequences from both H. pylori and other Helicobacter species.

CONCLUSIONS

The low H. pylori antigen detection rate in children >1 month of age is in accordance with previous prevalence studies from Western countries. The unexpected finding of a high H. pylori antigen detection rate in neonates suggests that transient colonization may occur in the neonatal period.

Epidemiology of Helicobacter pylori infection

Helicobacter pylori infection is now recognised as a worldwide problem. It is the most common cause of chronic gastritis, and is strongly linked to peptic ulcer disease and gastric cancer. While the infection is usually acquired in childhood, there is typically a long period of latency with disease manifestations not appearing until adulthood. Gastric cancer does not usually manifest until old age. The infection has a high morbidity rate, but a low mortality rate and is curable with antibiotic therapy.