The cohort effect and Helicobacter pylori

Changes in prevalence of Helicobacter pylori in Japan from 2008 to 2018: a repeated cross-sectional study

OBJECTIVES

To understand the recent prevalence and time trends of Helicobacter pylori infection rates in the Japanese population.

DESIGN

Repeated cross-sectional study.

PARTICIPANTS

A total of 22 120 workers (age: 35-65 years) from one Japanese company, who underwent serum H. pylori antibody tests in a health check-up between 2008 and 2018.

MEASURES

H. pylori infection rates among participants aged 35 years from 2008 to 2018, and participants aged 35, 40, 45, and 50-65 years in 2018, based on the results of serum antibody tests, were analysed. In the 2018 analysis, in addition to the antibody test results, all participants who had undergone eradication treatment for H. pylori were considered as infected. Trends were examined using joinpoint analysis.

RESULTS

H. pylori was detected in 1100 of 7586 male and 190 of 1739 female participants aged 35 years. Annual infection rates among those aged 35 years showed linear downward trends as follows: men, 17.5% in 2008 to 10.1% in 2018 (slope: -0.66); women, 12.3% in 2008 to 9.2% in 2018 (slope: -0.51) without joinpoints. In the 2018 analysis, 2432 of 9580 men and 431 of 1854 women were H. pylori positive. Infection rates tended to increase with older age (men: 11.0% (35 years) to 47.7% (65 years); women: 10.0% (35 years) to 40.0% (65 years)), and showed joinpoints in both sexes (men: 54 years; women: 45 years). Although both the first and second trends were upward, the second trend for both men and women was steeper than the first trend (p<0.05).

CONCLUSIONS

Our study demonstrated that in the previous 11 years, infection rates of H. pylori in 35-year-old male and female Japanese workers have constantly decreased, and furthermore, analysis of various age groups showed joinpoints around 50 years, suggesting a consistent declining trend in H. pylori infection rates in Japan.

Worldwide Prevalence and Risk Factors of Helicobacter pylori Infection in Children

Helicobacter pylori is usually acquired during childhood. The reports from the last two decades pointed out a decrease in H. pylori prevalence across geographical areas worldwide compared to previously reported data. Most of the studies performed in America found an overall H. pylori infection prevalence of approximately 50%. The most important risk factors in America include being male, poor adherence or difficult access to treatment, and the lack of in-home water service. Despite the descending trend in prevalence worldwide, the overall prevalence in Africa remains very high (70%). Nevertheless, the prevalence of H. pylori in children without gastrointestinal who underwent screening was reported to be only 14.2%. The main risk factors in Africa are having a traditional pit or no toilet, poverty, birth order, source of drinking water, or being a farmer. Asia seems to have the widest variations in terms of H. pylori prevalence. Several risk factors were reported in Asia to be associated with this infection, such as lower income and educational level, house crowding, rural residence, ethnicity, the use of tanks as water supplies, alcohol drinking, active smoking, eating spicy food or raw uncooked vegetables, poor living conditions and sanitation. The overall prevalence of H. pylori infection in European children is almost 25%. Portugal has the highest prevalence of all European countries at 66.2% in children 13 years of age. The risk factors in European individuals consist of living in rural areas, eating unwashed fruits and vegetables, not washing hands after school, low parental education and unemployment, and short education duration. Further studies are required to identify the precise mechanisms involved in the discrepancies of H. pylori prevalence worldwide.

Epidemiology Helicobacter pylori infection in children in the Tyva Republic (Russia)

BACKGROUND

Tyva Republic is a small mountainous area at the geographical center of Asia in southern Siberia, with a high incidence of gastric cancer.

AIM

We examined the prevalence of H. pylori and associated risk factors among children in Tyva.

METHODS

Cross-sectional study was conducted among Tuvan children who had upper gastrointestinal symptoms and underwent upper gastroscopy with gastric biopsies. Informed consent was obtained from the parents and assent from the children. Demographic information, ethnicity, parents' education and employment status, and family size were collected. H. pylori infection was diagnosed by histologic examination.

RESULTS

There were 270 children between the ages 7 and 17 years (mean 13.4 ± 2.7); 64% girls; 147e Tuvan and 123 Caucasians. The overall prevalence of H. pylori was high and similar between boys and girls (55 vs. 57%, respectively, p = 0.42). The infection was highest in Tuvan children (67%. vs. 43%, respectively (OR = 2.4; 95%CI = 1.9.4-3), p = 0.05. H. pylori prevalence increased with age from 44% among 7 to 10 years and 64% among those 14 to 17 (OR = 3.0; 95%CI = 1.6-5.8), p = 0.0.005; the pattern was consistent among both ethnic groups. The prevalence of the infection among Caucasian children was inversely correlated with the level of mother's education (44%, vs. 61%) (i.e., for with and without a college education the OR = 2.3; 95%CI = 1.2-3.7), p = 0.02. Neither the total number of children nor adults living in the same household correlated with H. pylori prevalence.

CONCLUSIONS

Strategies to reduce the incidence of gastric cancer in Tyva will need to start in childhood.

Epidemiology of Helicobacter pylori in Australia: a scoping review

Background

Helicobacter pylori (H. pylori), a bacterium implicated in the development of peptic ulcer and gastric cancer, is estimated to infect around half the world's population. Its prevalence in Australia is unclear. This scoping review aimed to evaluate all Australian literature providing estimates of the prevalence of H. pylori.

Methods

Australian studies examining H. pylori prevalence from 1982 onwards were eligible for inclusion. Medline, Embase and Scopus databases, and grey literature sources, were searched. Two independent reviewers undertook a two-stage screening process. Data were extracted by two independent reviewers using a pre-specified template.

Results

Of 444 identified studies, 75 were included in the review. H. pylori prevalence in Australian population-based studies (n = 8) ranged from 38.0% in 1991 to 15.1% in 2002; however, estimated prevalence across all non-clinical population studies in diverse sub-groups (n = 29) has varied dramatically. Decreased prevalence has been more marked in populations with gastrointestinal symptoms and conditions compared to non-clinical populations. Data on H. pyloriprevalence in vulnerable populations are lacking.

Conclusions

This is the first scoping review of Australian studies reporting H. pylori prevalence. A wide range of study designs, population groups, geographic regions, and diagnostic methods was included, involving data collected over a 50-year period (1969 to 2018). The summary of H. pylori prevalence estimates over time in this review points to a decrease in prevalence in Australia, particularly among populations with gastrointestinal symptoms and illnesses; however, it is unknown whether there is inequity in prevalence trends across vulnerable sub-groups of the Australian population. Future research and interventions supporting the health and wellbeing of vulnerable populations is required to ensure equitable health gains are made for all.

Asymptomatic Helicobacter pylori infection among rural children and adolescents in Bangladesh

Background and objectives: The Helicobacter pylori infection rate varies according to the age, location of the residence and socioeconomic status. The aim of the present study was to investigate the status of H. pylori infection among the asymptomatic Bangladeshi rural children and adolescents. Material and methods: This cross-sectional study was carried out in a rural area under Pabna district about 150 km north-west of capital Dhaka. Asymptomatic and apparently healthy rural children and adolescents aged 6 to 18 years were enrolled in the study. A structured questionnaire was used to record the socio-demographic and clinical information. The rate of H. pylori infection was determined by the presence of H. pylori antigen in faeces and/or anti-H. pylori IgG and/or IgA antibodies in blood. H. pylori stool antigen was detected by lateral flow chromatographic immunoassay and serum anti-H. pylori IgG and IgA antibodies were estimated by ELISA method. Results: A total number of 185 asymptomatic and apparently healthy children and adolescents were enrolled of which 34, 131 and 20 were in 6-10, 11-15 and 16-18 years age groups respectively. The overall H. pylori infection rate was 79.5% (95% CI: 0.729, 0.85) by positive stool antigen or by the presence of serum anti-H. pylori IgG/IgA antibodies. The rate of H. pylori infection significantly (p=0.05) increased with progress of age. H. pylori infection rate was 67.6%, 80.2% and 95% in 6-10, 11-15 and 16-18 years age groups respectively. The concentration of serum anti-H. pylori IgG/IgA antibodies did not differ across the age groups. The infection rate was significantly (p<0.05) higher among the children of illiterate parents compared to the children of literate parents. Conclusion: The study demonstrated a high prevalence of H. pylori infection among children and adolescents in a rural setting. Gender and family history did not affect H. pylori prevalence but increasing age and poor educational status of parents were associated with a higher H. pylori prevalence. IMC J Med Sci 2022; 16(2): 007. DOI: https://doi.org/10.55010/imcjms.16.017 *Correspondence: J. Ashraful Haq, Department of Microbiology, Ibrahim Medical College, 1/A, Ibrahim Sarani, Segunbagicha, Dhaka 1000, Bangladesh. Email: jahaq54@yahoo.com

Effects of Helicobacter pylori infection in gastrointestinal tract malignant diseases: From the oral cavity to rectum

Helicobacter pylori (H. pylori) has infected approximately fifty percent of humans for a long period of time. However, improvements in the public health environment have led to a decreased chance of H. pylori infection. However, a high infection rate is noted in populations with a high incidence rate of gastric cancer (GC). The worldwide fraction of GC attributable to H. pylori is greater than 85%, and a high H. pylori prevalence is noted in gastric mucosa-associated lymphoid tissue lymphoma patients. These results indicate that the majority of GC cases can be prevented if H. pylori infection is eliminated. Because H. pylori exhibits oral-oral or fecal-oral transmission, the relationship between this microorganism and other digestive tract malignant diseases has also attracted attention. This review article provides an overview of H. pylori and the condition of the whole gastrointestinal tract environment to further understand the correlation between the pathogen and the host, thus allowing improved realization of disease presentation.

Epidemiology of Helicobacter pylori

In many countries alike, the time trends of gastric cancer, gastric and duodenal ulcer, ulcerative colitis, Crohn's disease, and colorectal cancer are characterized by similar birth-cohort patterns. Mortality from these diagnoses rose in cohorts born during the 19th century and then fell in subsequent cohorts born during the 20th century.

On the Verge of a Catastrophic Collapse? The Need for a Multi-Ecosystem Approach to Microbiome Studies

While the COVID-19 pandemic has led to increased focus on pathogenic microbes that cross the animal-human species barrier, calls to include non-pathogenic interactions in our perspective on public health are gaining traction in the academic community. Over generations, the diversity of the human gut microbiota is being challenged by external perturbations and reduced acquisition of symbiotic species throughout life. When such reduced diversity concerns not only the microbial species, but also the higher taxonomic levels and even the guild level, adequate compensation for possible losses may be lacking. Shifts from a high-abundance to a low-abundance state, known as a tipping point, may result in simultaneous shifts in covarying taxa and ultimately to a catastrophic collapse in which the ecosystem abruptly and possibly irreversibly shifts to an alternative state. Here, we propose that co-occurrence patterns within and between microbial communities across human, animal, soil, water, and other environmental domains should be studied in light of such critical transitions. Improved mechanistic understanding of factors that shape structure and function is needed to understand whether interventions can sustainably remodel disease-prone microbiota compositions to robust and resilient healthy microbiota. Prerequisites for a rational approach are a better understanding of the microbial interaction network, both within and inter-domain, as well as the identification of early warning signs for a catastrophic collapse, warranting a timely response for intervention. We should not forget that mutualism and pathogenicity are two sides of the same coin. Building upon the planetary health concept, we argue that microbiome research should include system level approaches to conserve ecosystem resilience. HIGHLIGHTS 1. Non-pathogenic interactions between ecosystems play a key role in maintaining health. 2. The human gut microbiome may be on the verge of a catastrophic collapse. 3. Research should identify keystone taxa and guilds that interconnect different domains. 4. We should not forget that mutualism and pathogenicity are two sides of the same coin.

Role of the Gastric Microbiome in Gastric Cancer: From Carcinogenesis to Treatment

The development of sequencing technology has expanded our knowledge of the human gastric microbiome, which is now known to play a critical role in the maintenance of homeostasis, while alterations in microbial community composition can promote the development of gastric diseases. Recently, carcinogenic effects of gastric microbiome have received increased attention. Gastric cancer (GC) is one of the most common malignancies worldwide with a high mortality rate. Helicobacter pylori is a well-recognized risk factor for GC. More than half of the global population is infected with H. pylori, which can modulate the acidity of the stomach to alter the gastric microbiome profile, leading to H. pylori-associated diseases. Moreover, there is increasing evidence that bacteria other than H. pylori and their metabolites also contribute to gastric carcinogenesis. Therefore, clarifying the contribution of the gastric microbiome to the development and progression of GC can lead to improvements in prevention, diagnosis, and treatment. In this review, we discuss the current state of knowledge regarding changes in the microbial composition of the stomach caused by H. pylori infection, the carcinogenic effects of H. pylori and non-H. pylori bacteria in GC, as well as the potential therapeutic role of gastric microbiome in H. pylori infection and GC.

Polymerase chain reaction-based tests for detecting Helicobacter pylori clarithromycin resistance in stool samples: A meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infection is closely associated with the etiology of a variety of gastric diseases. The effective eradication of H. pylori infection has been shown to reduce the incidence of gastric carcinoma. However, the rate of H. pylori eradication has significantly declined due to its increasing resistance to antibiotics, especially to clarithromycin. Therefore, the detection of clarithromycin resistance is necessary prior to the treatment of H. pylori. Although many studies have been conducted on the use of polymerase chain reaction (PCR)-based tests to detect clarithromycin resistance in stool samples, no accurate data on the feasibility of these tests are available. Here, we performed a meta-analysis to assess the feasibility of these noninvasive tests.

AIM

To evaluate the reliability of PCR-based tests for detecting H. pylori clarithromycin resistance in stool samples.

METHODS

We searched PubMed, Medline, Embase, and other databases for articles that evaluated the value of the PCR analysis of stool samples for detecting the resistance of H. pylori to clarithromycin. We collected cross-sectional studies that met the inclusion criteria. Diagnostic accuracy measures were pooled using a random-effects model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Subgroup analysis was also conducted according to PCR type, purification technique, reference standard, mutation site, sample weight, number of patients, and age group, and the clinical utility of diagnostic tests was evaluated using the Likelihood Ratio Scatter Graph.

RESULTS

Out of the 1818 identified studies, only 11 met the eligibility criteria, with a total of 592 patients assessed. A meta-analysis of the random-effect model showed that PCR-based analysis of stool samples had high diagnostic accuracy for detecting clarithromycin resistance in patients infected with H. pylori. The combined sensitivity was 0.91 [95% confidence interval (CI): 0.83-0.95], Q = 30.34, and I² = 67.04, and the combined specificity was 0.97 (95%CI: 0.62-1.00), Q = 279.54, and I² = 96.42. The likelihood ratio for a positive test was 33.25 (95%CI: 1.69-652.77), and that for a negative test was 0.10 (95%CI: 0.05-0.18), with an area under the curve of 0.94. The diagnostic odds ratio was 347.68 (95%CI: 17.29-6991.26). There was significant statistical heterogeneity, and the sub-analyses showed significant differences in the number of patients, sample weight, purification methods, PCR types, mutation points, and reference standards. The included studies showed no risk of publication bias.

CONCLUSION

PCR-based tests on stool samples have high diagnostic accuracy for detecting H. pylori clarithromycin resistance.

Helicobacter pylori eradication therapy to prevent gastric cancer: systematic review and meta-analysis

OBJECTIVES

Gastric cancer is strongly associated with Helicobacter pylori (H. pylori). We conducted a previous systematic review and meta-analysis that suggested eradication therapy reduced future incidence of gastric cancer, but effect size was uncertain, and there was no reduction in gastric cancer-related mortality. We updated this meta-analysis, as more data has accumulated. We also evaluated impact of eradication therapy on future risk of gastric cancer in patients having endoscopic mucosal resection for gastric neoplasia.

DESIGN

We searched the medical literature through February 2020 to identify randomised controlled trials (RCTs) examining effect of eradication therapy on subsequent occurrence of gastric cancer in healthy H. pylori-positive adults, and in H. pylori-positive patients with gastric neoplasia undergoing endoscopic mucosal resection. The control arm received placebo or no treatment. Follow-up was for ≥2 years. We estimated the relative risk (RR) number needed to treat (NNT), and evaluated the disability-adjusted life-years (DALYs) gained from screening from the meta-analysis.

RESULTS

We identified 10 RCTs, seven recruited 8323 healthy individuals, and three randomised 1841 patients with gastric neoplasia. In healthy individuals, eradication therapy reduced incidence of gastric cancer (RR=0.54; 95% CI 0.40 to 0.72, NNT=72), and reduced mortality from gastric cancer (RR=0.61; 95% CI 0.40 to 0.92, NNT=135), but did not affect all-cause mortality. These data suggest that 8 743 815 DALYs (95% CI 5 646 173 to 11 847 456) would be gained if population screening and treatment was implemented globally. In patients with gastric neoplasia, eradication therapy also reduced incidence of future gastric cancer (RR=0.49; 95% CI 0.34 to 0.70, NNT=21). Adverse events were incompletely reported.

CONCLUSION

There is moderate evidence to suggest that H. pylori eradication therapy reduces the incidence of gastric cancer in healthy individuals and patients with gastric neoplasia in East Asian countries. There also appears to be a reduction in gastric cancer-related mortality.

Clinical and economic impact of "triple therapy" for Helicobacter pylori eradication on peptic ulcer disease in Australia

BACKGROUND

Helicobacter pylori infection has had a major impact on the global health of billions of people. Triple therapy was extensively used in Australia by 1986 for H pylori eradication after its discovery in 1984 and was critical in reducing the morbidity and mortality associated with this infection.

AIMS

This study analyzed hospital admission, mortality, and therapeutic data to determine the economic and clinical impact that antibiotic triple therapy had on peptic ulcer disease (PUD) in Australia.

METHODS

An analysis of indirect and direct cost-savings in Australia between 1990 and 2015 associated with triple therapy and the impact on PUD mortality and hospital admissions.

RESULTS

The direct and indirect impacts of PUD treated by triple therapy between 1990 and 2015 suggest that triple therapy is likely to have prevented 18 665 deaths, and saved 258 887 life years and 33 776 productive life years. The total savings, over the 26-year period, including direct and indirect costs, are calculated to be $10.03 billion, equating to an average annual saving of $393.419 million.

CONCLUSIONS

This study highlights the enormous benefits to Australia's health care of the discovery of triple therapy, a relatively low-cost antibiotic regimen which brought considerable savings via the reduction in morbidity (hospital admissions) and mortality related to PUD. It is likely that benefits of similar scale occurred internationally.

Stomach microbiota, Helicobacter pylori, and group 2 innate lymphoid cells

The stomach has been thought to host few commensal bacteria because of the existence of barriers, such as gastric acid. However, recent culture-independent, sequencing-based microbial analysis has shown that the stomach also harbors a wide diversity of microbiota. Although the stomach immune system, especially innate lymphoid cells (ILCs), has not been well elucidated, recent studies have shown that group 2 ILCs (ILC2s) are the dominant subtype in the stomach of both humans and mice. Stomach ILC2s are unique in that their existence is dependent on stomach microbiota, in sharp contrast to the lack of an impact of commensal microbiota on ILC2s in other tissues. The microbiota dependency of stomach ILC2s is partly explained by their responsiveness to interleukin (IL)-7. Stomach ILC2s express significantly higher IL-7 receptor protein levels on their surface and proliferate more in response to IL-7 stimulation in vitro than small intestinal ILC2s. Consistently, the stomach expresses much higher IL-7 protein levels than the small intestine. IL-5 secreted from stomach ILC2s promotes immunoglobulin (Ig) A production by plasma B cells. In a murine model, stomach ILC2s are important in containing Helicobacter pylori infection, especially in the early phase of infection, by promoting IgA production.

Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly

BACKGROUND

The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years.

METHODS

Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994-1995, 2004-2005, and 2014-2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting.

RESULTS

Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10-29 years decreased from 1994 (60.0%-85.0%) to 2015 (12.5%-28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15-19 year-old group in 1994-1995 (85.0%) to the 40-49 year-old group in 2014-2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years.

CONCLUSION

H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.

Individual and household correlates of Helicobacter pylori infection among Young Ethiopian children in Ziway, Central Ethiopia

Background

Investigating distinct individual- and household-level risk factors for acquiring Helicobacter pylori (H. pylori) infection can inform disease prevention efforts and implicate possible routes of transmission. This study determined the magnitude of H. pylori infection among schoolchildren in Ziway, central Ethiopia and identified personal and household correlates of H. pylori infection in young Ethiopian children.

Methods

A total of 434 schoolchildren participated in this cross-sectional study. Infection status was assessed using antigen and antibody rapid tests. Demographic and lifestyle information was obtained from parents via an interviewer-led questionnaire. Univariate and multivariate logistic regressions were performed to assess the relationships between potential individual- and household-level risk factors and H. pylori infection.

Results

The prevalence of H. pylori infection was 65.7% (285/434). Of the personal variables assessed, the age group 10–14 years was found to be significantly associated with higher odds of H. pylori infection in univariate analysis (COR = 2.22, 95% CI: 1.06–4.66, p = 0.03) and remained positively correlated after adjusting for confounding factors. Of the household-level factors explored, having a traditional pit or no toilet was found to be significantly associated with 3.93-fold higher odds of H. pylori infection (AOR = 3.93, 95% CI: 1.51–10.3, p = 0.01), while the presence of smokers in the household was associated with 68% lower odds of infection (AOR = 0.32, 95% CI: 0.11–0.89, p = 0.03).

Conclusion

This study from a developing country provides additional evidence for older age as a personal risk factor for H. pylori infection and identifies correlations between socioeconomic and sanitation household factors and positive childhood infection status. The associations reported here support the hypothesized fecal-oralroute of transmission for H. pylori.

Low Prevalence of Helicobacter pylori-Positive Peptic Ulcers in Private Outpatient Endoscopy Centers in the United States

OBJECTIVES

During the past decades, the prevalence of gastric and duodenal ulcers, as well as Helicobacter pylori infection, has markedly declined. We hypothesized that the decline in H. pylori prevalence has decreased the fraction of H. pylori-positive gastric and duodenal ulcers. The present study was designed to test this hypothesis in a large US population undergoing esophagogastro-duodenoscopy in community-based endoscopy centers.

METHODS

The Inform Diagnostics database is a national electronic repository of histopathologic records of patients distributed throughout the United States. A cross-sectional study among 1,289,641 individual esophagogastro-duodenoscopy patients analyzed the prevalence of peptic ulcers stratified by age, sex, ethnicity, H. pylori status, year of diagnosis, and ulcer type. The joint influence of multiple predictor variables on the occurrence of gastric and duodenal ulcers was analyzed using multivariate logistic regression analysis.

RESULTS

Between 2009 and 2018, the general prevalence of H. pylori infection fell significantly from 11% to 9%. This decline was accompanied by a similar decline in the fraction of H. pylori-positive gastric ulcers from 17% to 14% and H. pylori-positive duodenal ulcers from 25% to 21%. Nowadays, only 17% of all patients with ulcer harbor H. pylori. The fraction of H. pylori-positive ulcers was significantly greater in duodenal than in gastric ulcers and in male than in female patients with ulcer. The prevalence of H. pylori was 2.6-fold higher among Hispanics and 3.2-fold higher among East Asians compared with the general population. The H. pylori prevalence fell from 24% to 22% among Hispanics and from 21% to 15% among East Asians. In East Asians and Hispanics, the fraction of H. pylori-positive gastric ulcers was 37% and 35%, respectively.

DISCUSSION

H. pylori infection continues to fall in the general population. Nowadays, even among patients with ulcer only a small minority harbors H. pylori infection.

Alterations to the Esophageal Microbiome Associated with Progression from Barrett's Esophagus to Esophageal Adenocarcinoma

BACKGROUND

The incidence of esophageal adenocarcinoma has risen dramatically over the past half century, and the underlying reasons are incompletely understood. Broad shifts to the upper gastrointestinal microbiome may be partly responsible. The goal of this study was to describe alterations in the esophageal microbiome that occur with progression from Barrett's esophagus to esophageal adenocarcinoma.

METHODS

A case-control study was performed of patients with and without Barrett's esophagus who were scheduled to undergo upper endoscopy. Demographic, clinical, and dietary intake data were collected, and esophageal brushings were collected during the endoscopy. 16S rRNA gene sequencing was performed to characterize the microbiome.

RESULTS

A total of 45 patients were enrolled and included in the analyses [16 controls; 14 Barrett's esophagus without dysplasia (NDBE); 6 low-grade dysplasia (LGD); 5 high-grade dysplasia (HGD); and 4 esophageal adenocarcinoma]. There was no difference in alpha diversity between non-Barrett's esophagus and Barrett's esophagus, but there was evidence of decreased diversity in patients with esophageal adenocarcinoma as assessed by Simpson index. There was an apparent shift in composition at the transition from LGD to HGD, and patients with HGD and esophageal adenocarcinoma had decreased Firmicutes and increased Proteobacteria. In addition, patients with HGD or esophageal adenocarcinoma had increased Enterobacteriaceae and Akkermansia muciniphila and reduced Veillonella. In the study population, patients taking proton pump inhibitors had increased Streptococcus and decreased Gram-negative bacteria overall.

CONCLUSIONS

Shifts in the Barrett's esophagus-associated microbiome were observed in patients with HGD and esophageal adenocarcinoma, with increases in certain potentially pathogenic bacteria.

IMPACT

The microbiome may play a role in esophageal carcinogenesis.

Prevalence of Helicobacter pylori infection in Latin America and the Caribbean populations: A systematic review and meta-analysis

OBJECTIVE

To describe the prevalence of Helicobacter pylori (H. pylori) infection in Latin Americaand the Caribbean (LAC), through systematic review and meta-analysis by age groups and gender.

METHODS

Systematic review and meta-analysis of the population-based observational epidemiological studies carried out in LAC, focused on the prevalence of H. pylori and published until March, 2018. The databases utilized in the search were MEDLINE, SCIELO andPUBMED. The prevalence described in the meta-analysis and 95% confidence intervals were estimated by the random effects model, and weighted by the size of the study.

RESULTS

The 22 selected studies were carried out in 14 countries of LAC, and included 24,178 individuals. The studies were conducted between 1987 and 2012, and all were representative of at least one city. The prevalence of H. pylori infection was 57.57% (CI95%:50.43;64.72) for all ages; in children and adolescents the prevalence was 48.36% (CI95%:38.03;58.70) and in adults 69.26%(CI95%:64.54;76.99). No differences were observed regarding sex.

CONCLUSION

Prevalence of H. pylori infection in LAC is high for all age groups. These data reinforce the necessity of actions towards the prevention and treatment of H. pylori infection for all age groups. Treating H pylori infection in young ages probably will reduce gastric cancer incidence in the future.

The cost effectiveness of Helicobacter pylori population screening-economic evaluation alongside a randomised controlled trial with 13-year follow-up

BACKGROUND

Helicobacter pylori eradication improves dyspeptic symptoms in 8%-10%, prevents peptic ulcer and may reduce the risk of gastric cancer. Availability of a high quality diagnostic test and an effective treatment makes population screening and eradication of Helicobacter pylori an attractive option.

AIM

To evaluate the cost effectiveness of Helicobacter pylori population screening and eradication.

METHODS

Cost effectiveness analysis and cost utility analysis alongside randomised controlled trial with 13 years follow-up. The evaluation has a societal perspective. A random general population sample of 20 011 individuals aged 40-65 were randomised and invited in 1998-1999; 12 530 were enrolled and, of these, 8658 have been successfully followed up at 1, 5, and 13 years after intervention. Questionnaires included the quality of life instrument SF-36. From SF-36 responses an SF-6D score was derived and used for calculation of quality-adjusted life years. Register data on costs, use of health care resources and medication were obtained for all randomised individuals. The intervention was an invitation to Helicobacter pylori screening by in-office blood test; positive tests were validated by ¹³ C-urea breath test. Those who tested positive were offered eradication therapy. Main outcome measures were Incremental cost per quality-adjusted life year and life-years gained.

RESULTS

Helicobacter pylori population screening and eradication with 13 years follow-up was not effective in regards to quality of life and the cost per screened person was higher than not screening (mean difference 11 269 DKK [95% CI: 3175-19 362]). The probability of being cost-effective was 80% at a threshold of 400 000 DKK (approximately 53,800 Euros) of willingness-to-pay per life-year gained.

CONCLUSIONS

Helicobacter pylori population screening and eradication with 13 years follow-up was not effective in regards to quality of life and the cost of screening was higher than not screening.

Helicobacter pylori: History and facts in Peru

Helicobacter pylori (H. pylori) is a cosmopolite bacteria and the main responsible for the high burden of gastric cancer in developing countries, such as Peru. In this review, we describe some historical facts in the H. Pylori discovery, the first researches of this bacterium in Peru, as well as its epidemiology, clinical characteristics, diagnosis, treatments, and outcomes. Our literature and review of real-life data suggest that several efforts should be conducted in our country to deal with antibiotic-resistance and lack of adherence to treatment in order to reduce our incidence of gastric cancer.

Diagnosis of Helicobacter pylori Infection in Children and Adolescents in Korea

Helicobacter pylori plays an important role in the pathogenesis of chronic gastritis, peptic ulcer disease, gastric cancer, and gastric mucosa-associated lymphoid tissue lymphoma. In Korea, the guidelines for the diagnosis and treatment of H. pylori infection in adults were revised in 2013. The European Helicobacter and Microbiota Study Group and Consensus panel released the fifth edition of the Maastricht Consensus Report for the management of H. pylori infection in 2015, and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition and the North American Society of Paediatric Gastroenterology, Hepatology and Nutrition released the updated joint guidelines for children and adolescents in 2016. Considering these recommendations and recent progress in our research and that of other research teams, this study aimed to discuss the diagnostic strategies for H. pylori infection in children and adolescents.

Emerging Insights into the Esophageal Microbiome

PURPOSE OF REVIEW

Analysis of the esophageal microbiome remains a relatively new field of research, and most studies to date have focused on characterizing the esophageal microbiome in states of health and disease. Microbiome alterations have been implicated in the pathogenesis of inflammatory and neoplastic conditions in the colon and elsewhere in the gastrointestinal tract. The epidemiology of various esophageal conditions including Barrett's esophagus (BE), esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC), and eosinophilic esophagitis (EoE) point to the microbiome as a potential co-factor in disease pathogenesis, and the possibility exists that these microbiome alterations could contribute directly to the inflammatory environments necessary for the carcinogenesis or atopy involved in these conditions.

RECENT FINDINGS

The native esophageal microbiome is similar in composition to the oral microbiome, with a high relative abundance of the phylum Firmicutes and the genus Streptococcus. Limited studies to date suggest that there are certain microbiome alterations associated with esophageal diseases. Additionally, it may be possible to indirectly assess the esophageal microbiome via non-endoscopic means. This raises the possibility that non-invasive microbiome analysis could be used for disease screening and monitoring. Further understanding of the role of the esophageal microbiome in disease pathogenesis, as well as methods for microbiome alteration, may help elucidate future targets for disease modifying therapies, or minimally invasive screening tools in patients at high risk for development of various esophageal conditions.

The Epidemiology of Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in many Western countries and is higher in men than women. Some risk factors for EAC have been identified-mainly gastroesophageal reflux disease, Barrett's esophagus, obesity, and tobacco smoking. It is not clear whether interventions to address these factors can reduce risk of EAC, although some evidence exists for smoking cessation. Although consumption of alcohol is not associated with EAC risk, other exposures, such as physical activity, nutrition, and medication use, require further study. Genetic variants have been associated with risk for EAC, but their overall contribution is low. Studies are needed to investigate associations between risk factors and the molecular subtypes of EAC. The prognosis for patients with EAC has slightly improved, but remains poor-screening and surveillance trials of high-risk individuals are needed.

Epidemiology of Helicobacter pylori infection in asymptomatic schoolchildren in Bhutan

AIM

Bhutan is a small mountainous country between Tibet and India with relatively homogenous population. According to the World Health Organization, gastric cancer is the most frequent cause of cancer death in Bhutan. This study examined the prevalence of Helicobacter pylori among children in Bhutan with emphasis on water source and living conditions.

METHODS

A cross-sectional sero-epidemiologic study was conducted among schoolchildren who attended public schools in Thimphu, Bhutan. Between 2015 and 2016, blood samples from schoolchildren were collected after obtaining an informed consent from the school management and the children's parents. Demographic information, parents' education, family size living in the same household, and aspects of household environment including type of latrines, boiling drinking water were collected. All serum samples were tested for H. pylori immunoglobulin G (IgG) by commercial ELISA kits.

RESULTS

There were 327 children between 4 and 19 years of age participated, 44% boys, mean age = 13.6 ± 3 years. The overall prevalence of H. pylori was 66% with no difference between boys and girls (66 vs 64%, respectively), P = .42. H. pylori prevalence was 75% among both 4-7 and 15-19 years and not statically different from that of the 8-10 or 11-14 age groups (59% and 63%, respectively), P = .1. H. pylori prevalence was inversely correlated with the level of mother's education (70% vs 55%) for those without and with a college education, respectively (OR = 2.3; 95%CI = 0.9-1.7), P = .08. The total number of people living in the same household did not correlate with H. pylori sero-prevalence, but households had less than 3 children had lower prevalence than those with 3 or more children (62% vs 71%, respectively OR = 1.7, 95% CI = [1.0-2.6], P = .05).

CONCLUSIONS

H. pylori infection is prevalent among all age group children in Bhutan. The results suggest that transmission of H. pylori is related to personal care practices that directly correlate with the mothers' education and crowded living condition with children. Our results are important to developing prevention strategies for gastric cancer in Bhutan.

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.

Usefulness of detection of clarithromycin-resistant Helicobacter pylori from fecal specimens for young adults treated with eradication therapy

BACKGROUND

To prevent Helicobacter pylori infection in the younger generation, it is necessary to investigate the prevalence of antibiotic-resistant H. pylori.

OBJECTIVE

The aim of this study was to evaluate the method of PCR-based sequencing to detect clarithromycin (CAM) resistance-associated mutations using fecal samples as a noninvasive method.

METHODS

DNA extracted from fecal specimens and isolates from gastric biopsy specimens were collected from patients with H. pylori infection. Antibiotic resistance to CAM was analyzed by molecular and culture methods. The detection rates of CAM resistance-associated mutations (A2142C or A2143G) were compared before and after eradication therapy.

RESULTS

With CAM resistance of H. pylori evaluated by antibiotic susceptibility test as a gold standard, the sensitivity and the specificity of gene mutation detection from fecal DNA were 80% and 84.8%, respectively. In contrast, using DNA of isolated strains, the sensitivity and the specificity were 80% and 100%. Of the seven cases in which eradication was unsuccessful by triple therapy including CAM, CAM-resistant H. pylori, and resistance-associated mutations were detected in three cases, CAM-resistant H. pylori without the mutation was detected in two patients, and resistance-associated mutation was only detected in one patient.

CONCLUSION

PCR-based sequencing to detect CAM resistance-associated mutations using isolates or fecal samples was useful for finding antibiotic-resistant H. pylori infection. Although the specificity of the detection from fecal samples compared with antibiotic susceptibility testing was lower than that from isolates, this fecal detection method is suitable especially for asymptomatic subjects including children. Further improvement is needed before clinical application.

Association between infection with Helicobacter pylori and atopy in young Ethiopian children: A longitudinal study

BACKGROUND

Epidemiological evidence from developed countries indicates that Helicobacter pylori infection correlates with a reduced risk of atopy and allergic disorders; however, limited data are available from low-income countries.

OBJECTIVE

We examined associations between H. pylori infection in early childhood and atopy and reported allergic disorders at the age of 6.5 years in an Ethiopian birth cohort.

METHODS

A total of 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half years. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Questions on allergic disease symptoms were based on the International Study of Asthma and Allergies in Children (ISAAC) core allergy and environmental questionnaire. Serum samples were analysed for total IgE levels and anti-H. pylori cytotoxin-associated gene A (CagA) IgG antibody using commercially available ELISA kits. Stool samples were analysed for H. pylori antigen using a rapid immunochromatographic test. The independent effects of H. pylori infection (measured at age of 3, 5 and 6.5 years) on prevalence and incidence of atopy and reported allergic disorders (measured at age of 6.5 years) were determined using multiple logistic regression.

RESULTS

In cross-sectional analysis, current H. pylori infection at age 6.5 years was inversely, though not significantly, related to prevalence of atopy and "any allergic condition" at age 6.5 years. However, detection of H. pylori infection at any point up to age 6.5 years was associated with a significantly reduced odds of both atopy and "any allergic condition" (adjusted OR AOR, 95% CI, 0.54; 0.32-0.92, P = .02, and .31; 0.10-0.94, P = .04, respectively). In longitudinal analyses, H. pylori infection at age 3 was inversely associated with incidence of atopy (AOR, 95% CI, 0.49; 0.27-0.89, P = .02). Furthermore, among H. pylori-infected children, those with a CagA+ strain had a more pronounced reduction in odds of atopy (AOR = 0.35 vs 0.63 for CagA+ vs CagA-), and this reduction reached borderline significance.

CONCLUSION

These data are consistent with the hypothesis that early exposure to H. pylori is inversely associated with atopy and allergic conditions. A possible modest protective association against atopy was observed in those infected with a more virulent CagA+ strain of H. pylori.

幽门螺杆菌根除治疗在胃癌预防中的现状及前景

幽门螺杆菌(Helicobacter pylori, H. pylori)与胃癌(gastric cancer, GC)发生发展密切相关, 根除H. pylori可降低GC发生率. 经济学分析表明, 在高危人群中根除治疗H. pylori作为预防GC的策略是成本效益较好的. 即使在GC低风险人群中, H. pylori筛查和治疗也能使上消化道其他非恶性疾病获益. 然而, 广泛开展H. pylori根除治疗可能带来其他问题, 包括抗生素耐药增加和与H. pylori负相关疾病(如胃食管反流病、Barrett食管、哮喘和肥胖等)的患病率升高. 本文将结合近年最新研究, 就上述问题展开论述, 进一步提出H. pylori根除治疗预防GC所面临的挑战以及将来可能的进展方向.

Helicobacter pylori infection and its related factors in junior high school students in Nagano Prefecture, Japan

BACKGROUND

There have been few reports on Helicobacter pylori (H. pylori) infection in asymptomatic Japanese children and adolescents. We hypothesized that the prevalence of H. pylori infection is very low among Japanese children and that clinical variables such as serum pepsinogen and iron levels are associated with H. pylori infection.

MATERIALS AND METHODS

We conducted a cross-sectional analysis of a sample of 454 junior high school students aged 12-15 years in four areas in Nagano Prefecture. A commercial ELISA kit (E-plate Eiken H. pylori antibody) was used to measure IgG antibody against H. pylori. Serum pepsinogen and iron levels were also measured using standard methods. A urea breath test was performed for seropositive students.

RESULTS

The overall prevalence of H. pylori was 3.1% (14/454). There were no significant differences in H. pylori prevalence among mountain, rural, and urban areas. The mean level of both serum pepsinogen (PG I) and PG II was significantly increased in the seropositive subjects compared with the seronegative subjects. When the cutoff values for adults (PG I: 70 ng/mL and PG I/II ratio: 3) were used, 4 of 14 subjects had PG I ≤70 ng/mL and PG I/II ratio ≤3. The results of a logistic regression analysis showed that low serum iron levels were significantly associated with H. pylori infection (P=.02).

CONCLUSIONS

The prevalence of H. pylori infection is as low as 3% among junior high school students aged 12-15 years in Japan. The disappearance of H. pylori is accelerating in Japanese children.

Population screening and treatment of Helicobacter pylori infection

Helicobacter pylori is an important human pathogen, associated with a substantial burden from both malignant and non-malignant diseases. The bacterium is classed as a human carcinogen, being strongly linked with gastric cancer, the third most common cause of cancer death worldwide and is also associated with common conditions such as dyspepsia and peptic ulcer. Eradication of H. pylori reduces the incidence of gastric cancer and peptic ulcer, as well as the prevalence and costs of managing dyspepsia. Economic analyses suggest that eradication of H. pylori as a means of controlling gastric cancer is cost-effective in high-risk populations. Even in populations at low risk of gastric cancer, there might be other benefits arising from screening and treatment, owing to the effects on non-malignant upper gastrointestinal diseases. However, public health authorities have been slow to consider the benefits of population-based screening and treatment as a means of reducing the morbidity and mortality associated with the infection. There are also concerns about widespread use of eradication therapy, including antimicrobial resistance and a rise in the prevalence of diseases that are negatively associated with H. pylori, such as GERD, Barrett oesophagus, asthma and obesity. This Review summarizes these issues.

'The Microbiome and the Pathophysiology of Asthma'

Asthma is a chronic respiratory disease whose prevalence is increasing in the western world. Recently research has begun to focus on the role the microbiome plays in asthma pathogenesis in the hope of further understanding this respiratory disorder. Considered sterile until recently, the lungs have revealed themselves to contain a unique microbiota. A shift towards molecular methods for the quantification and sequencing of microbial DNA has revealed that the airways harbour a unique microbiota with apparent, reproducible differences present between healthy and diseased lungs. There is a hope that in classifying the microbial load of the asthmatic airway an insight may be afforded as to the possible role pulmonary microbes may have in propagating an asthmatic airway response. This could potentially pave the way for new therapeutic strategies for the treatment of chronic lung conditions such as asthma.

Potential Role of the Microbiome in Barrett's Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma and its precursor Barrett's esophagus have been rapidly increasing in incidence for half a century, for reasons not adequately explained by currently identified risk factors such as gastroesophageal reflux disease and obesity. The upper gastrointestinal microbiome may represent another potential cofactor. The distal esophagus has a distinct microbiome of predominantly oral-derived flora, which is altered in Barrett's esophagus and reflux esophagitis. Chronic low-grade inflammation or direct carcinogenesis from this altered microbiome may combine with known risk factors to promote Barrett's metaplasia and progression to adenocarcinoma.

Gastric adenocarcinoma screening and prevention in the era of new biomarker and endoscopic technologies: a cost-effectiveness analysis

OBJECTIVE

To estimate the cost-effectiveness of noncardia gastric adenocarcinoma (NCGA) screening strategies based on new biomarker and endoscopic technologies.

DESIGN

Using an intestinal-type NCGA microsimulation model, we evaluated the following one-time screening strategies for US men: (1) serum pepsinogen to detect gastric atrophy (with endoscopic follow-up of positive screen results), (2) endoscopic screening to detect dysplasia and asymptomatic cancer (with endoscopic mucosal resection (EMR) treatment for detected lesions) and (3) Helicobacter pylori screening and treatment. Screening performance, treatment effectiveness, cancer and cost data were based on published literature and databases. Subgroups included current, former and never smokers. Outcomes included lifetime cancer risk and incremental cost-effectiveness ratios (ICERs), expressed as cost per quality-adjusted-life-year (QALY) gained.

RESULTS

Screening the general population at age 50 years reduced the lifetime intestinal-type NCGA risk (0.24%) by 26.4% with serum pepsinogen screening, 21.2% with endoscopy and EMR and 0.2% with H. pylori screening/treatment. Targeting current smokers reduced the lifetime risk (0.35%) by 30.8%, 25.5%, and 0.1%, respectively. For all subgroups, serum pepsinogen screening was more effective and more cost-effective than all other strategies, although its ICER varied from $76,000/QALY (current smokers) to $105,400/QALY (general population). Results were sensitive to H. pylori prevalence, screen age and serum pepsinogen test sensitivity. Probabilistic sensitivity analysis found that at a $100,000/QALY willingness-to-pay threshold, the probability that serum pepsinogen screening was preferred was 0.97 for current smokers.

CONCLUSIONS

Although not warranted for the general population, targeting high-risk smokers for serum pepsinogen screening may be a cost-effective strategy to reduce intestinal-type NCGA mortality.

Meta-analysis of association between Helicobacter pylori infection and multiple sclerosis

Despite recent research focus on the association between Helicobacter pylori (H. pylori) infection and multiple sclerosis (MS) there is no consensus about the findings. To obtain a more comprehensive estimate of the association we conducted a meta-analysis to determine the prevalence of H. pylori infection in MS patients and healthy controls. Pubmed and EMBASE were searched to identify eligible studies. Nine studies were selected for inclusion, involving 2806 cases (1553 patients with MS and 1253 controls). Overall, the prevalence of H. pylori infection in MS patients was lower than that in control groups (24.66% vs. 31.84%, OR=0.69, 95% CI: 0.57-0.83, P<0.0001). Subgroup analysis revealed that the levels of H.pylori infection among MS patients were lower than for control subjects in Western countries (11.90% vs. 16.08%, OR=0.63, 95% CI: 0.43-0.91, P=0.01), but were not statistically significant in Eastern countries (39.39% vs. 43.82%, OR=0.79, 95% CI: 0.55-1.14, P=0.20). Our data show that H. pylori infection and MS is negatively correlated, especially in Western countries. Whether H. pylori infection is a protective factor against MS risk should thus be addressed in large-scale and prospective studies.

Association between Helicobacter pylori and intestinal parasites in an Añu indigenous community of Venezuela

BACKGROUND

Helicobacter pylori (Hp) and enteroparasite infections are highly prevalent in populations with poor living conditions, like the Amerindian communities. Identifying associations between both types of infectious agents could help to detect shared risk factors or transmission routes in these minority ethnic groups. Therefore, the prevalence and association between Hp and enteroparasites were investigated in an indigenous community whose living conditions favor such infectious diseases.

METHODS

Seropositivity (anti-Hp-specific IgG) and active infection (stool antigen test), intestinal parasitosis (direct and concentrated coproparasitological test, methylene blue, and Kinyoun stains), and risk factors for fecal-oral transmission were determined in 167 children and 151 adults of the Añu indigenous community living at the Sinamaica Lagoon, in Venezuela.

RESULTS

A high rate of Hp infection (seropositivity and active infection) and enteroparasitosis was evidenced, as expected. Some significant associations were detected: direct associations between Hp and polyparasitic infection, helminths, and protozoan (particularly in children); inverse association between Hp and Giardia lamblia. No shared epidemiological factors were identified for Hp and the detected intestinal parasites, probably due to overlapping factors.

CONCLUSION

Direct associations detected support the participation of the fecal-oral route in the transmission of the involved infectious agents. Inverse relationship (Hp) and G. lamblia may suggest the existence of antagonistic interactions between them. Further research is required to elucidate the mechanisms underlying these associations.

Inverse Relationship Between Helicobacter Pylori Infection and Asthma Among Adults Younger than 40 Years: A Cross-Sectional Study

Recent studies have suggested that Helicobacter pylori could prevent allergic disease, particularly in children. However, whether this is true in adults is controversial. The aim of this study was to investigate whether there is negative association between H. pylori infection and asthma among adults in an area with a high prevalence of H. pylori.This was a cross-sectional study using 2011 health surveillance data. Blood samples were taken from all participants to measure serum H. pylori IgG status. Information on demographics, socioeconomic status, and medical history, including asthma and other allergic conditions were collected by a questionnaire.Of the 15,032 patients, 9492 (63.1%) had a history of H. pylori infection, 359 (2.4%) had asthma, and 3277 (21.8%) had other allergic conditions. H. pylori infection was positively correlated with age (OR, 1.050; 95% CI, 1.047-1.053, P < 0.001). Asthma history was positively correlated with age (OR, 1.022; 95% CI, 1.013-1.032, P < 0.001). H. pylori and age were shown to have interaction on asthma in the total participants (OR, 1.041; 95% CI, 1.021-1.062, P < 0.001). In subgroup analysis, H. pylori infection among those < 40 years old was inversely correlated with asthma (OR, 0.503; 95% CI, 0.280-0.904, P = 0.021). Other allergic conditions were not related with H. pylori infection among the total and those <40 years old.The inverse association between H. pylori infection and asthma among young adults suggests that the underlying immune mechanism induced by H. pylori infection may affect allergic reactions associated with asthma in young adults.

The homing receptor CD44 is involved in the progression of precancerous gastric lesions in patients infected with Helicobacter pylori and in development of mucous metaplasia in mice

Infection with Helicobacter pylori (H. pylori) leads to inflammatory events that can promote gastric cancer development. Immune cells transition from the circulation into the infected mucosa through the interaction of their receptors and ligands in the endothelial compartment. CD44 expression is increased in advanced gastric lesions. However, the association of this molecule with the progression of these lesions over time has not been investigated. In addition, there is a lack of understanding of the CD44-dependent cellular processes that lead to gastritis, and possibly to gastric cancer. Here we studied H. pylori-positive subjects with gastric lesions that ranged from multifocal atrophic gastritis to dysplasia to determine gene expression changes associated with disease progression over a period of 6 years. We report that CD44 expression is significantly increased in individuals whose gastric lesions progressed along the gastric precancerous cascade. We also show that CD44-/- mice develop less severe and less extensive H. pylori-induced metaplasia, and show fewer infiltrating Gr1+ cells compared to wild type mice. We present data suggesting that CD44 is associated with disease progression. Mechanisms associated with these effects include induction of interferon gamma responses.

Gastric cancer incidence in the Romagna Region of Italy: A spatial and temporal analysis

BACKGROUND

The worldwide decrease in gastric cancer incidence is due to a birth-cohort-dependent decrease in exposure to major risk factors.

METHODS

In an area of northern Italy with a historically strong internal geographical gradient in gastric cancer incidence, variations in rates by municipality and age group between 1987 and 2008 were evaluated. The study period was divided into three nonadjacent periods. End points included: age- and sex-standardised incidence rates; incidence rate ratio between age- and sex-standardised incidence rates; smoothed relative risks of gastric cancer incidence, and posterior probabilities of the relative risk being >1.

RESULTS

In 1987-1990, the estimate of posterior probabilities of relative risk being >1 showed a higher incidence in hilly/mountainous areas. Between 1987-1990 and 2005-2008, a uniform decrease of more than 50% was observed (incidence rate ratio: plain, 0.45 (95% confidence interval 0.40-0.51); hill, 0.44 (0.34-0.58); mountain, 0.48 (0.22-1.02)). The decrease in the mountainous area was weak in the middle time period, with an incidence rate ratio of 0.92 (0.46-1.84), and intensified afterwards. The decrease occurred earlier and was more pronounced among younger people. In 2005-2008, gastric cancer risk was uniform across ages and municipalities.

CONCLUSIONS

The observed changes in gastric cancer incidence is the epilogue of a birth-cohort-dependent decrease in exposure to major risk factors.

A combined antral and corpus rapid urease testing protocol can increase diagnostic accuracy despite a low prevalence of Helicobacter pylori infection in patients undergoing routine gastroscopy

BACKGROUND

The effects of an increased risk of sampling error and the lower prevalence of Helicobacter pylori infection on the diagnostic accuracy of standard invasive tests needs to be considered. Despite evidence of enhanced yield with additional biopsies, combined Rapid Urease Tests (RUTs) have not been widely adopted. We aimed to compare the diagnostic efficacy of a combined antral and corpus rapid urease test (RUT) to a single antral RUT in a low prevalence cohort.

METHODS

Between August 2013 and April 2014 adult patients undergoing a scheduled gastroscopy were prospectively recruited. At endoscopy biopsies were taken and processed for single and combined RUTs, histology and culture using standard techniques. Infection was defined by positive culture or detection of Helicobacter like organisms on either antral or corpus samples.

RESULTS

In all 123 patients were recruited. H. pylori prevalence was low at 36%, n = 44. There was a significant difference in positivity between single and combined RUTs, 20% (n = 25) versus 30% (n = 37), p = 0.0094, (95% CI 0.15-0.04). The number needed to treat (NNT) for an additional diagnosis of infection using a combined versus a single RUT is 4 (95% CI 2.2-11). The only factor associated with a reduction in RUT yield was regular proton pump inhibitor (PPI) use. Overall the sensitivity, specificity, positive and negative predictive value for any RUT test was 84%, 100%, 100% and 92% respectively.

CONCLUSION

Our data suggests taking routine antral and corpus biopsies in conjunction with a combined RUT appears to optimizing H. pylori detection and overcome sampling error in a low prevalence population.

The Prevalence of Helicobacter pylori Remains High in African American and Hispanic Veterans

BACKGROUND

Helicobacter pylori in the United States has been declining in the 1990s albeit less so among blacks and Hispanics. As the socioeconomic status of racial groups has evolved, it remains unclear whether the prevalence or the racial and ethnic disparities in the prevalence of H. pylori have changed.

METHODS

This is a cross-sectional study from a Veteran Affairs center among patients aged 40-80 years old who underwent a study esophagogastroduodenoscopy with gastric biopsies, which were cultured for H. pylori irrespective of findings on histopathology. Positive H. pylori was defined as positive culture or histopathology (stained organism combined with active gastritis). We calculated age-, race-, and birth cohort-specific H. pylori prevalence rates and examined predictors of H. pylori infection in logistic regression models.

RESULTS

We analyzed data on 1200 patients; most (92.8%) were men and non-Hispanic white (59.9%) or black (28.9%). H. pylori was positive in 347 (28.9%) and was highest among black males aged 50-59 (53.3%; 44.0-62.4%), followed by Hispanic males aged 60-69 (48.1%; 34.2-62.2%), and lowest in non-Hispanic white males aged 40-49 (8.2%; 2.7-20.5%). In multivariate analysis, age group 50-59 was significantly associated with H. pylori (adjusted odds ratio (OR), 2.32; 95% confidence interval (CI), 1.21-4.45) compared with those aged 40-49, and with black race (adjusted OR, 2.57; 95% CI, 1.83-3.60) and Hispanic ethnicity (adjusted OR, 3.01; 95% CI, 1.70-5.34) compared with non-Hispanic white. Irrespective of age group, patients born during 1960-1969 had a lower risk of H. pylori (adjusted OR, 0.45; 95% CI, 0.22-0.96) compared to those born in 1930-1939. Those with some college education were less likely to have H. pylori compared to those with no college education (adjusted OR 0.51; 95% CI, 0.37-0.69).

CONCLUSION

Among veterans, the prevalence of active H. pylori remains high (28.9%) with even higher rates in blacks and Hispanics with lower education levels.