Relation of adult lifestyle and socioeconomic factors to the prevalence of Helicobacter pylori infection

Prevalence and risk factors of H. pylori infection among outpatient in Karaganda city (Kazakhstan)

BACKGROUND

To better understand the factors associated with Helicobacter pylori infection, it is important to quantify the prevalence of H. pylori and identify the clinical and demographic characteristics of individuals with the infection.

METHOD

In this cross-sectional study 369 participants underwent a structured questionnaire, urease breath test, and endoscopy to determine their H. pylori status.

RESULTS

The frequency of H. pylori in the sample was 27.64%, and erosive antral gastritis, gastric ulcers, and duodenal ulcers were found to be significantly associated with infection. However, no differences were found in social status, family size, or shared utensil use between individuals with and without the infection.

CONCLUSION

These findings suggest that H. pylori is a significant risk factor for gastrointestinal conditions.

Human immunodeficiency virus and Helicobacter pylori coinfection: Immune modulation and eradication failure

The relationship between Human Immunodeficiency Virus (HIV) and Helicobacter pylori (H. pylori) is bidirectional and complex. Helicobacter pylori, by inducing local gastric and systemic immune responses, counteracts HIV invasion to CD4+ cells and other inflammatory cells and can reactivate HIV in latently infected immune cells. Human Immunodeficiency Virus infection, by reducing secretion of pro-inflammatory cytokines, reduces the incidence of H. pylori-induced gastric pathology. Gastric lymphoma regressed in some cases of people living with HIV (PLWH) after H. pylori eradication. Triple therapy for H. pylori could be associated with a strong immune. Treatment for both H. pylori and HIV can reduce the activation of either organism. However, the primary resistance to antibiotics such as levofloxacin, clarithromycin and metronidazole is higher among PLWH. This review highlights the need for further research and guidelines on the appropriate antibiotics in HIV-H. pylori co-infection particularly in PLWH who receive multiple antibiotic prophylaxis.

Seroprevalence of Helicobacter pylori and incident myocardial infarction - A population-based Swedish nested case-control study

AIMS

Helicobacter pylori (H. pylori) and its cytotoxin-associated gene A (CagA) have been associated with myocardial infarction (MI), but existing data are conflicting possibly due to limitations in study designs and lack of data on important confounders. The aim of this study was to determine whether H. pylori or CagA seropositivity is associated with incident MI, including MI phenotypes, and to describe temporal trends.

METHODS

We used the Northern Sweden Health and Disease study, a prospective biobank with data from residents enrolled in a population-based cohort from health examinations between 1986 and 2006. A total of 826 first time MI cases with available blood samples from their index health examination were identified up to 2006. Each case was 1:2 matched with controls by age, sex, sample date and geographical area. Blood samples were analysed using ELISA to determine seroprevalence of H. pylori and CagA, which were then used to study the association with incident MI.

RESULTS

The median age at baseline was 50 years, and 71% of participants were male. Seroprevalence of H. pylori and CagA was 46.5% and 32.1% in cases, respectively, compared to 43.7% and 30.6% in controls. Overall, H. pylori prevalence decreased over the study period. After multivariable adjustments, no significant association was observed between H. pylori seropositivity and incident MI (odds ratio: 1.15, 95% CI 0.94-1.42) nor between CagA-positive H. pylori and incident MI.

CONCLUSION

In a Swedish population-based cohort, no significant association was observed between H. pylori or CagA seropositivity and incidence of MI.

Prevalence and associated risk factors of Helicobacter pylori infection in community households in Lanzhou city

BACKGROUND

Helicobacter pylori (H. pylori) infection exhibits a familial clustering phenomenon.

AIM

To investigate the prevalence of H. pylori infection, identify associated factors, and analyze patterns of transmission within families residing in the community.

METHODS

From July 2021 to September 2021, a total of 191 families (519 people) in two randomly chosen community health service centers in the Chengguan District of Lanzhou in Gansu Province, were recruited to fill out questionnaires and tested for H. pylori infection. Individuals were followed up again from April 2023 and June 2023 to test for H. pylori infection. The relationship between variables and H. pylori infection was analyzed using logistic regression and generalized linear mixed models.

RESULTS

In 2021, the individual-based H. pylori infection rate was found to be 47.0% (244/519), which decreased to 38.1% (177/464) in 2023. Additionally, the rate of individual-based H. pylori new infection was 22.8% (55/241). The family-based H. pylori infection rate in 2021 was 76.9% (147/191), which decreased to 67.1% (116/173) in 2023, and the rate of family-based H. pylori new infection was 38.6% (17/44). Individual H. pylori infection was positively correlated with age, body mass index (BMI), eating food that was excessively hot, frequent acid reflux, bloating, and halitosis symptoms, and negatively correlated with family size and nut consumption. New individual H. pylori infection was positively correlated with BMI, other types of family structures, drinking purified water, and frequent heartburn symptoms, while negatively correlated with the use of refrigerators and following a regular eating schedule. A larger living area was an independent protective factor for H. pylori infection in households. Frequently consuming excessively hot food and symptoms of halitosis were independent risk factors for H. pylori infection in individuals; frequent consumption of nuts was an independent protective factor for H. pylori infection. Other types of family structure, drinking purified water, and frequent heartburn symptoms were independent risk factors for new individual H. pylori infection; the use of a refrigerator was an independent protective factor for new H. pylori infections.

CONCLUSION

The household H. pylori infection rate in Lanzhou is relatively high and linked to socio-demographic factors and lifestyles. Eradication efforts and control of related risk factors are recommended in the general population.

Distinguishing Features of Autoimmune Gastritis Depending on Previous Helicobacter pylori Infection or Positivity to Anti-Parietal Cell Antibodies: Results From the Autoimmune gastRitis Italian netwOrk Study grOup (ARIOSO)

INTRODUCTION

To describe the clinical features and the risk of developing gastric tumors in patients with autoimmune gastritis (AIG).

METHODS

This was a retrospective, longitudinal, multicenter study conducted at 8 Italian tertiary referral centers. We retrieved clinical data from all histologically proven patients with AIG. Differences between Helicobacter pylori -exposed vs H. pylori -naive and anti-parietal cell antibody (PCA)-positive vs PCA-negative patients were investigated. The rate of gastric adenocarcinoma and type 1 gastric neuroendocrine neoplasm (gNEN) was assessed. A multivariable model for factors associated with gNEN was fitted.

RESULTS

A total of 1,598 patients with AIG (median age 58 years, interquartile range 46-68; F:M ratio 2.7:1) were included. H. pylori -naive patients were more likely to have a first-degree family history of AIG (14.7% vs 8.9%; P = 0.012), type 1 diabetes mellitus (4.9% vs 2.3%; P = 0.025), and pernicious anemia (30.9% vs 21.1%; P = 0.003). PCA-positive patients had significantly more associated autoimmune diseases (59.0% vs 42.9%; P < 0.001) and were more likely to have been diagnosed by a case-finding strategy (15.3% vs 2.6%; P < 0.001). Overall, 15 cases (0.9%) of gastric adenocarcinoma and 153 cases (9.6%) of gNEN occurred, with a global rate of 0.12 (95% confidence interval [CI] 0.07-0.20) and 1.22 (95% CI 1.03-1.42) per 100 person/year, respectively. Having a vitamin B12/iron deficiency manifestation at AIG diagnosis was associated with a 16.44 (95% CI 9.94-27.20 P < 0.001) hazard ratio of gNEN.

DISCUSSION

The "pure" AIG pattern has typical features of an autoimmune disease and seems to be unrelated to H. pylori . In a tertiary referral setting, the risk of developing overt gastric adenocarcinoma is low, while patients with vitamin B12 deficiency complications at onset may benefit from a more intense endoscopic follow-up for early gNEN detection.

Kill Two Birds with One Stone? The Effect of Helicobacter pylori Eradication in Decreased Prevalence of Gastric Cancer and Colorectal Cancer

The connection between microbial infections and tumor formation is notably exemplified by Helicobacter pylori (H. pylori) and its association with gastric cancer (GC) and colorectal cancer (CRC). While early studies hinted at a link between H. pylori and colorectal neoplasms, comprehensive retrospective cohort studies were lacking. Recent research indicates that individuals treated for H. pylori infection experience a significant reduction in both CRC incidence and mortality, suggesting a potential role of this infection in malignancy development. Globally, H. pylori prevalence varies, with higher rates in developing countries (80-90%) compared to developed nations (20-50%). This infection is linked to chronic gastritis, peptic ulcers, and GC, highlighting the importance of understanding its epidemiology for public health interventions. H. pylori significantly increases the risk of non-cardia GC. Some meta-analyses have shown a 1.49-fold increased risk for colorectal adenomas and a 1.70-fold increase for CRC in infected individuals. Additionally, H. pylori eradication may lower the CRC risk, although the relationship is still being debated. Although eradication therapy shows promise in reducing GC incidence, concerns about antibiotic resistance pose treatment challenges. The role of H. pylori in colorectal tumors remains contentious, with some studies indicating an increased risk of colorectal adenoma, while others find minimal association. Future research should investigate the causal mechanisms between H. pylori infection and colorectal neoplasia, including factors like diabetes, to better understand its role in tumor formation and support widespread eradication efforts to prevent both gastric and colorectal cancers.

Helicobacter pylori exposure among the Awajún of the Peruvian Amazon: Prevalence and environmental, social, and biological associations

OBJECTIVES

Helicobacter pylori (H. pylori)-a gastric bacteria affecting almost 50% of the global population and leading to ulcers and cancer in severe cases-is a growing health concern among Indigenous populations who report a high burden of reported poor general health and gastrointestinal distress. We test hypothesized associations between H. pylori exposure patterns and environmental, social, and biological conditions among a sample of 212 Indigenous Awajún adults (112 males, 100 females, ages 18-65 years) living in the northern Peruvian Amazon.

MATERIALS AND METHODS

Dried blood spots were analyzed for H. pylori-specific IgG using a recently developed enzyme-linked immunosorbent assay. Resulting seropositivity rates and antibody concentrations, proxying past exposures to H. pylori were analyzed in relation to relevant environmental (toilet type, floor material, reported water quality), social (household size and education level), and biological (age, sex, BMI, blood pressure, immune and metabolic biomarkers) factors using multivariable regression analyses.

RESULTS

We found near ubiquitous seropositivity for H. pylori exposure in our sample (99.1% seropositive). In the regression analyses, elevations in H. pylori antibody concentrations were significantly higher among males compared to females (β = 0.36, p = 0.01). No associations were found with any other factors.

DISCUSSION

Anthropological research in the study communities suggests that the male bias in elevations of H. pylori antibody concentrations is related to cultural and biological factors. Future research is needed to further unravel these biocultural dynamics and determine whether elevations in H. pylori antibody concentrations have clinical relevance for gastrointestinal health outcomes in this population.

Dose-response association between cigarette smoking and gastric cancer risk: a systematic review and meta-analysis

This study aims at providing an accurate and up-to-date quantification of the dose-response association between cigarette smoking and gastric cancer (GC) risk, overall and by subsite. We conducted a systematic review and meta-analysis of case-control and cohort studies on the association between cigarette smoking and GC risk published up to January 2023. We estimated pooled relative risks (RR) of GC and its subsites according to smoking status, intensity, duration, and time since quitting. Among 271 eligible articles, 205 original studies were included in this meta-analysis. Compared with never smokers, the pooled RR for GC was 1.53 (95% confidence interval; CI 1.44-1.62; n = 92) for current and 1.30 (95% CI 1.23-1.37; n = 82) for former smokers. The RR for current compared with never smokers was 2.08 (95% CI 1.66-2.61; n = 21) for gastric cardia and 1.48 (95% CI 1.33-1.66; n = 8) for distal stomach cancer. GC risk nonlinearly increased with smoking intensity up to 20 cigarettes/day (RR:1.69; 95% CI 1.55-1.84) and levelled thereafter. GC risk significantly increased linearly with increasing smoking duration (RR: 1.31; 95% CI 1.25-1.37 for 20 years) and significantly decreased linearly with increasing time since quitting (RR: 0.65; 95% CI 0.44-0.95 for 30 years since cessation). The present meta-analysis confirms that cigarette smoking is an independent risk factor for GC, particularly for gastric cardia. GC risk increases with a low number of cigarettes up to 20 cigarettes/day and increases in a dose-dependent manner with smoking duration.

The evaluation of the MMP-2/TIMP-1 ratio in peptic ulcer and its association with refractory helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) is one of the leading causes of peptic ulcers, and its treatment is a worldwide challenge. Matrix metalloproteinases and their inhibitors influence the development and healing of peptic ulcers. This study aimed to evaluate the ratios of matrix metalloproteinase-2 (MMP-2) to tissue inhibitor of metalloproteinase-1 (TIMP-1) in patients with peptic ulcers that are sensitive or resistant to H. pylori treatment and compare them with healthy individuals.

METHODS

In this study, 95 patients were included and divided into two groups sensitive (41 patients) and resistant to treatment (54 patients). The results were compared with a control group of 20 participants with normal endoscopy and H. pylori-negative. After obtaining written informed consent, five ml of venous blood was taken to determine their serum MMP-2 and TIMP-1 levels using an enzyme-linked immunosorbent assay.

RESULTS

In patients with H. pylori-induced peptic ulcers, the MMP-2/TIMP-1 ratio was significantly higher than the healthy controls (P < 0.05). MMP-2 level was associated with patients' response to treatment (P < 0.05). The MMP-2/TIMP-1 ratio was higher in patients with simultaneous gastric and duodenal ulcers (P < 0.05).

CONCLUSION

It seems that peptic ulcer disease caused by infection with H. pylori increases the MMP-2/TIMP-1 ratio in patients with peptic ulcers. However, it might not be a good predictor of refractory H. pylori-induced peptic ulcer disease.

Risk of gastric carcinoma will be low in generations born at turn of the 20th and 21st centuries in Finland. Modelling NORDCAN data of the age group specific incidence rates of gastric cancer with PLS-regression and with attention to age ('age effect') and year of the birth ('cohort effect')

BACKGROUND AND METHODS

We examined in NORDCAN database how the annual age group-specific incidence rates (IR) of gastric cancer (GCA), and correspondingly the GCA risk, have declined in Finland during the twentieth century, and whether this decline corresponds to a decrease in the cohort-specific prevalence rate of Helicobacter pylori (Hp) gastritis that is considered an important precancerous risk condition for GCA.

RESULTS

In modelling with partial least squares regression (PLSR), the logarithmically transformed IRs (ln(IR) of GCA were well explained with age and birth cohort as explanatory model variables. By considering the observed (actual) and the PLSR-modelled IRs, the IR of GCA (and the risk of GCA) has decreased gradually in Finland from 1900 onward, cohort by cohort. By prediction of the future with PLSR, the IRs of GCA will be markedly lower in all cohorts during the twenty-first century than in the twentieth century. By PLSR modelling, less than 10 GCA cases per 100,000 people are predicted to appear annually in cohorts (generations) born at the turn of the 20th and 21st centuries, even when these people will be 60-80 years old in the years 2060-2070.

CONCLUSIONS

The IR of GCA and GCA risk progressively declined by cohort in Finland during the whole twentieth century. This decline corresponds in extent and time window to earlier observations in the decline of the prevalence rate of Hp gastritis in the same birth cohorts and supports the hypothesis of the role of Hp gastritis as an important risk condition of GCA.

Association of Alcohol Drinking and Helicobacter pylori Infection : A Meta-analysis

BACKGROUND

The association between drinking and Helicobacter pylori infection was not clear in the literature. Owing to mixed and inconclusive results, a meta-analysis was conducted to summarize and clarify this association systematically.

METHODS

Based on a comprehensive search of PubMed, Embase, and Web of Science databases, studies investigating the association between drinking and H. pylori infection were retrieved. We evaluated the strength of this relationship using odds ratios (ORs) with 95% confidence intervals. Sensitivity analysis was also conducted.

RESULTS

A total of 24 individual studies were included in this meta-analysis. The risk of H. pylori infection was significantly lower in alcohol drinkers than nondrinkers (OR=0.83). People who drink wine (OR=0.90) or mixed types of alcoholic beverages (OR=0.78) had a lower risk of infection compared with those who drink beer. Among people aged 40 years or older, alcohol drinkers had a lower risk of H. pylori infection than nondrinkers (OR=0.68). Among people less than 40 years of age, alcohol drinking was not associated with H. pylori infection risk. Data showed that women were at a lower risk of H. pylori infection than men (OR=0.86).

CONCLUSIONS

This meta-analysis suggests that the risk of H. pylori infection among alcohol drinkers is lower than that of nondrinkers. Drinking wine and mixed types of alcohol are better at reducing H. pylori infection than drinking beer. Nonetheless, we discourage reducing H. pylori infection through drinking, which increases the risk of other diseases.

Diagnostic Challenges of Helicobacter pylori Infection in Ethiopia: A Community-Based Cross-Sectional Study

BACKGROUND

In resource-constrained countries, accurate diagnosis of Helicobacter pylori infection remains a challenge. This study aimed to assess the clinical utility of locally available serological and stool antigen test kits in the management of people with suspected H. pylori infection in Ethiopia.

METHODS

A community-based cross-sectional study was conducted with apparently healthy adults and children living in southwest Ethiopia. Participants were interviewed for dyspepsia symptoms and related clinical conditions. H. pylori infection was examined using commercially available serological and stool antigen tests. The association between H. pylori tests and dyspepsia symptoms was analyzed using logistic regression models.

RESULTS

Out of 1392 participants included in the final analysis, 49.1% and 6.5% tested positive for H. pylori infection with serology and stool antigen test kits, respectively. Participants reporting epigastric symptoms in the past three months (AOR = 1.93, 95% CI = 1.28-2.91) and those with recent dyspepsia treatment (AOR = 1.51, 95% CI = 1.05-2.18) were likely to have positive serology test. However, no association between dyspepsia symptoms and H. pylori stool antigen positivity was observed in our study.

CONCLUSION

ccurate detection of H. pylori infections using commercially accessible diagnostics remains difficult in Ethiopia. With these methods, it will be hard to ensure adequate diagnosis and early treatment of H. pylori infection, as well as rational antibiotic use.

Sociodemographic disparities in gastric cancer and the gastric precancerous cascade: A population-based study

BACKGROUND

Gastric carcinogenesis is a multistep process initiating with chronic gastritis and progressing through atrophy, intestinal metaplasia, and dysplasia to carcinoma. This study aims to comprehensively investigate sociodemographic disparities in each stage of gastric carcinogenesis and estimate to what extent the inequalities could be ascribed to risk factors of gastric cancer (GC).

METHODS

We used the baseline data from a community-based study in China's high-risk areas, totalling 27094 participants. Gastric mucosa status was ascertained by endoscopy and biopsies. An overall socioeconomic status (SES) variable was generated by latent class analysis. We calculated relative risks (RRs) and 95% confidence intervals (CIs) using modified Poisson regression to assess associations of sociodemographic factors with each cascade stage. We estimated the percentage of the excess risk for neoplastic lesions among vulnerable populations that can be explained by established risk factors.

RESULTS

Age and sex showed associations with all gastric lesions, whose RRs increased with lesion progressing. Compared with individuals without schooling, the RRs of neoplastic lesions for people with primary, secondary, and post-secondary education were 0·86 (95% CI 0·76-0·97), 1·00 (95% CI 0·88-1·13), and 0·70 (95% CI 0·47-1·03), respectively. Participants with medium SES had a lower risk of neoplastic lesions than people in the low SES group (RR 0·83, 95% CI 0·74-0·93). GC risk factors could explain 33·6% of the excess risk of neoplastic lesions among men and a small proportion of the disparities among SES groups.

INTERPRETATION

Age and sex were essential sociodemographic factors for GC and precursor diseases. Individuals with low educational levels or SES were more likely to have neoplastic lesions. About one-third of the sex difference and a slight fraction of the socioeconomic inequalities could be attributed to included risk factors.

FUNDING

Sanming Project of Medicine in Shenzhen, National Natural Science Foundation, and Special Project of Bejing-Tianjin-Hebei Basic Research Cooperation.

Evolution, the Immune System, and the Health Consequences of Socioeconomic Inequality

Healthy development and function of essentially all physiological systems and organs, including the brain, require exposure to the microbiota of our mothers and of the natural environment, especially in early life. We also know that some infections, if we survive them, modulate the immune system in relevant ways. If we study the evolution of the immune and metabolic systems, we can understand how these requirements developed and the nature of the organisms that we need to encounter. We can then begin to identify the mechanisms of the beneficial effects of these exposures. Against this evolutionary background, we can analyze the ways in which the modern urban lifestyle, particularly for individuals experiencing low socioeconomic status (SES), results in deficient or distorted microbial exposures and microbiomes. Thus, an evolutionary approach facilitates the identification of practical solutions to the growing scandal of health disparities linked to inequality.

Recruitment to a large scale randomised controlled clinical trial in primary care: the Helicobacter Eradication Aspirin Trial (HEAT)

Background

The Helicobacter Eradication Aspirin Trial (HEAT) is a multicentre, double blind, randomised controlled trial investigating whether Helicobacter (H.) pylori eradication reduces hospitalisation for peptic ulcer bleeding. Recruited participants were aged 60 and over and taking aspirin (≤325 mg daily) for at least four months prior to consent. Based on results of a pilot study, a sample size calculation predicted 6600 H. pylori-positive randomised participants would be required, from 33,000 volunteers, recruited from 170,000 invited patients. Methodology was therefore designed for recruitment of large numbers of patients from primary care using a novel electronic search tool, automated mail-out and electronic follow-up. Recruitment started in 2012 and completed in 2017.

Methods

All participants were recruited from GP practices, with assistance from the UK Clinical Research Network (UKCRN). H. pylori-positive participants were randomised to one week of eradication treatment or placebo. Recruitment was managed using a bespoke web-based database that communicated directly with a programmed search tool downloaded at participating practices. The primary endpoint is hospitalisation due to peptic ulcer bleeding. The trial will end when 87 adjudicated events have occurred, identified from searches of GP databases, review of secondary care admission data and mortality data, and reported events from randomised participants and GPs.

Results

HEAT has recruited participants from 1208 GP practices across the UK. Of the 188,875 invitation letters sent, 38,771 returned expressions of interest. Of these, 30,166 patients were consented to the trial, of whom 5355 H. pylori-positive participants (17.8% of those consented) were randomised.

Mean age at consent was 73.1 ± 6.9 (SD) years and 72.2% of participants were male. Of the randomised (H. pylori-positive) participants, 531 have died (as of 17 Sep 2020); none of the deaths was due to trial treatment.

Conclusion

The HEAT trial methodology has demonstrated that recruitment of large numbers of patients from primary care is attainable, with the assistance of the UKCRN, and could be applied to other clinical outcomes studies.

Trial registration

ClinicalTrials.gov; registration number NCT01506986. Registered on 10 Jan 2012.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06054-w.

When will Helicobacter pylori gastritis disappear in history in Finland?

OBJECTIVES

To predict how the10-year birth cohort specific prevalence rates of chronic non-atrophic (CG) and atrophic gastritis (AG), related to Helicobacter pylori (Hp) infection, will decline during the 21^st century among the native adult Finns.

MATERIALS AND METHODS

The predictions are based as continuums of our earlier observations of gradual and significant declines in birth cohort specific prevalence rates of CG and AG in endoscopic biopsies from gastric antrum and corpus of 2298 adult dyspeptic outpatients or asymptomatic volunteers born 1890-1977 that were endoscopied in 1972-1997 in Finland.

RESULTS AND DISCUSSION

We could predict that the Hp related CG and AG will gradually disappear in history among the native Finns during the 21^st century. From the 2020s onward, the CG and AG would decrease with time in prevalence rate, cohort-by-cohort, and would be more and more highlighted in the middle aged or elderly age groups only. Finally, since all birth cohorts (generations) infected with Hp have passed away by 2080, the Hp related gastrites would not appear anymore in notable counts among the native Finns. Correspondingly, gastric cancers and peptic ulcers (both duodenal and gastric), which are etiopathogenetically linked with Hp gastrites, would similarly become gradually more and more infrequent and rare disorders among native Finns during the 21^st century.

Next-Generation Sequencing-Based Study of Helicobacter pylori Isolates from Myanmar and Their Susceptibility to Antibiotics

Evaluation of Helicobacter pylori resistance to antibiotics is crucial for treatment strategy in Myanmar. Moreover, the genetic mechanisms involved remain unknown. We aimed to investigate the prevalence of H. pylori infection, antibiotic resistance, and genetic mechanisms in Myanmar. One hundred fifty patients from two cities, Mawlamyine (n = 99) and Yangon (n = 51), were recruited. The prevalence of H. pylori infection was 43.3% (65/150). The successfully cultured H. pylori isolates (n = 65) were tested for antibiotic susceptibility to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline by Etest, and the resistance rates were 80%, 33.8%, 7.7%, 4.6%, and 0%, respectively. In the multidrug resistance pattern, the metronidazole–levofloxacin resistance was highest for double-drug resistance (16/19; 84.2%), and all triple-drug resistance (3/3) was clarithromycin–metronidazole–levofloxacin resistance. Twenty-three strains were subjected to next-generation sequencing to study their genetic mechanisms. Interestingly, none of the strains resistant to clarithromycin had well-known mutations in 23S rRNA (e.g., A2142G, A2142C, and A2143G). New type mutation genotypes such as pbp1-A (e.g., V45I, S/R414R), 23S rRNA (e.g., T248C), gyrA (e.g., D210N, K230Q), gyrB (e.g., A584V, N679H), rdxA (e.g., V175I, S91P), and frxA (e.g., L33M) were also detected. In conclusion, the prevalence of H. pylori infection and its antibiotic resistance to metronidazole was high in Myanmar. The H. pylori eradication regimen with classical triple therapy, including amoxicillin and clarithromycin, can be used as the first-line therapy in Myanmar. In addition, next-generation sequencing is a powerful high-throughput method for identifying mutations within antibiotic resistance genes and monitoring the spread of H. pylori antibiotic-resistant strains.

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.

Helicobacter pylori infection in Iran: demographic, endoscopic and pathological factors

Background

Helicobacter pylori (H. pylori) infection is the most important risk factor for gastritis and peptic ulcer. However, factors other than H. pylori are involved in its pathogenesis. In the current study, we aimed to compare the clinical manifestations and endoscopic and histopathological findings of patients with and without H. pylori infection.

Methods

In this cross-sectional study, 233 patients with dyspepsia, referred for endoscopy, were examined regarding the presence of H. pylori infection. During an endoscopic exam, 5 biopsy specimens were taken from the stomach. The criteria for the presence of H. pylori infection was the presence and identification of bacteria in pathology. Two groups of H. pylori-positive and H. pylori-negative patients were compared regarding their demographic, endoscopic, and pathological findings.

Results

Of 233 patients, 154 (66.1%) were non-smokers, 201 (86.3%) were not alcohol users, and 153 (65.7%) used tap water. The most common symptom, reported in 157 (67.4%) patients, was epigastric pain. There was a significant difference between patients with and without H. pylori infection in terms of the educational status, occupational status, family history of gastrointestinal cancer, and some gastrointestinal symptoms. Also, there was a significant relationship between the endoscopic and pathological findings of patients with H. pylori.

Conclusions

The results of the present study revealed that H. pylori infection was not associated with sex, alcohol consumption, or non-steroidal anti-inflammatory drug use. The role of H. pylori in the pathophysiology of peptic ulcer was clarified. Also, there was a significant difference in the endoscopic and pathological findings of patients with H. pylori.

Prevalence rates of heathy stomach mucosa, chronic non-atrophic and atrophic gastritis in endoscopic biopsies in adults born in Finland in 1890-1977

BACKGROUND

Helicobacter pylori infection, chronic gastritis (CG) and atrophic gastritis (AG) are a continuum of consecutive events in the stomach mucosa. We studied the birth cohort and age group-specific prevalence rates of 'healthy' (N) and 'diseased' stomachs with CG or AG in endoscopic biopsies in adult people born in Finland in 1890-1977.

MATERIALS AND METHODS

Study series consisted of 690 and 1608 adults with a diagnostic gastroscopy in 1972-1997. All subjects were divided to 10-year age groups and birth cohorts. Based on biopsy histology, relative frequencies (prevalences) of N, CG and AG were estimated by the observed number of cases with N, CG and AG in each study category.

RESULTS

Prevalence rate of a histologically 'diseased' stomach (CG or AG) decreased and that of 'healthy' stomach (N) increased, cohort-by-cohort, from 1900 onward by rate 9-12% per every 10-year period in the two study subpopulations, respectively. Prevalences of CG remained unchanged over study groups when N, CG and AG were noted concurrently. By noting 'diseased' stomachs only, the prevalence rate of AG increased, and that of CG decreased with age, at rate 9-13% per every 10 years of calendar age.

CONCLUSIONS

Over 70-year period from 1900 onward, the prevalence rate of 'diseased' stomach (CG or AG) decreased and that of 'healthy' (N) stomach increased in birth cohorts over 50%, by rate about 10% over every 10-year period of time. In birth cohorts, CG progressed to AG with aging of the subjects at a rate of about 10% over every 10 years of calendar age.

Myths and misconceptions in the management of Helicobacter pylori infection

The discovery of Helicobacter pylori infection in 1984 revolutionised the management of several common upper gastrointestinal diseases. However, some of the clinical practices that were adopted following discovery of this organism have become less appropriate over the intervening years. This article discusses five 'myths and misconceptions' that we believe have now emerged and which we argue need re-evaluation. Although the prevalence of H. pylori infection is decreasing in some developed countries, it remains a huge global problem and the most serious consequence of infection, gastric adenocarcinoma, is still a major cause of mortality. The epidemiology of H. pylori-related diseases is also changing and careful testing remains crucially important, especially in patients with peptic ulceration. Eradication of H. pylori infection has also become much more difficult over recent years as a result of the widespread acquisition of antibiotic resistance. Routine assessment of the success of eradication should therefore now be performed. Finally, there has been increased awareness about the role of H. pylori in the multistep pathway of gastric carcinogenesis, about the opportunities to prevent cancer development by eradicating this infection in some individuals and about detecting high-risk preneoplastic changes via endoscopic surveillance. The discovery of H. pylori was rightly honoured by the award of the Nobel prize for Physiology and Medicine in 2005. However, unless we re-evaluate and update the ways in which we manage H. pylori infection, much of the fantastic progress that has been made in this field of medicine may tragically be lost once again.

Anthropometric and reproductive factors and risk of esophageal and gastric cancer by subtype and subsite: Results from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5-25 kg/m2 : HR = 1.94, 95% CI: 1.25-3.03) and women (HR = 2.66, 95% CI: 1.15-6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99-6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52-4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35-14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76-18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14-0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32-0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04-3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers.

Education and gastric cancer risk-An individual participant data meta-analysis in the StoP project consortium

Low socioeconomic position (SEP) is a strong risk factor for incidence and premature mortality from several cancers. Our study aimed at quantifying the association between SEP and gastric cancer (GC) risk through an individual participant data meta-analysis within the "Stomach cancer Pooling (StoP) Project". Educational level and household income were used as proxies for the SEP. We estimated pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) across levels of education and household income by pooling study-specific ORs through random-effects meta-analytic models. The relative index of inequality (RII) was also computed. A total of 9,773 GC cases and 24,373 controls from 25 studies from Europe, Asia and America were included. The pooled OR for the highest compared to the lowest level of education was 0.60 (95% CI, 0.44-0.84), while the pooled RII was 0.45 (95% CI, 0.29-0.69). A strong inverse association was observed both for noncardia (OR 0.39, 95% CI, 0.22-0.70) and cardia GC (OR 0.47, 95% CI, 0.22-0.99). The relation was stronger among H. pylori negative subjects (RII 0.14, 95% CI, 0.04-0.48) as compared to H. pylori positive ones (RII 0.29, 95% CI, 0.10-0.84), in the absence of a significant interaction (p = 0.28). The highest household income category showed a pooled OR of 0.65 (95% CI, 0.48-0.89), while the corresponding RII was 0.40 (95% CI, 0.22-0.72). Our collaborative pooled-analysis showed a strong inverse relationship between SEP indicators and GC risk. Our data call for public health interventions to reduce GC risk among the more vulnerable groups of the population.

The impact of race and socioeconomic status on the presentation, management and outcomes for gastric cancer patients: Analysis from a metropolitan area in the southeast United States

BACKGROUND

Socioeconomic disparities in gastric cancer have been associated with differences in care and inferior outcomes. We evaluated the presentation, treatment, and survival for patients with gastric cancer (GC) in a metropolitan setting with a large African American population.

METHODS

Retrospective cohort analysis of patients with GC (2003-2018) across a multi-hospital system was performed. Associations between socioeconomic and clinicopathologic data with the presentation, treatment, and survival were examined.

RESULTS

Of 359 patients, 255 (71%) were African American and 104 (29%) Caucasian. African Americans were more likely to present at a younger age (64.0 vs 72.5, P < .001), have state-sponsored or no insurance (19.7% vs 6.9%, P = .02), reside within the lowest 2 quintiles for median income (67.4% vs 32.7%, P < .001), and have higher rates of Helicobacter pylori (14.9% vs 4.8%, P = .02). Receipt of multi-modality therapy was not impacted by race or insurance status. On multivariable analysis, only AJCC T class (HR 1.68) and node positivity (HR 2.43) remained significant predictors of disease-specific survival.

CONCLUSION

Despite socioeconomic disparities, African Americans, and Caucasians with GC had similar treatment and outcomes. African Americans presented at a younger age with higher rates of H. pylori positivity, warranting further investigation into differences in risk factors and tumor biology.

Correlates of infection with Helicobacter pylori positive and negative cytotoxin-associated gene A phenotypes among Arab and Jewish residents of Jerusalem

We examined the prevalence and correlates of Helicobacter pylori (H. pylori) infection according to cytotoxin-associated gene A (CagA) phenotype, a main virulence antigen, among the ethnically diverse population groups of Jerusalem. A cross-sectional study was undertaken in Arab (N = 959) and Jewish (N = 692) adults, randomly selected from Israel's national population registry in age-sex and population strata. Sera were tested for H. pylori immunoglobulin G (IgG) antibodies. Positive samples were tested for virulence IgG antibodies to recombinant CagA protein, by enzyme-linked immunosorbent assay. Multinomial regression models were fitted to examine associations of sociodemographic factors with H. pylori phenotypes. H. pylori IgG antibody sero-prevalence was 83.3% (95% confidence interval (CI) 80.0%–85.5%) and 61.4% (95% CI 57.7%–65.0%) among Arabs and Jews, respectively. Among H. pylori positives, the respective CagA IgG antibody sero-positivity was 42.3% (95% CI 38.9%–45.8%) and 32.5% (95% CI 28.2%–37.1%). Among Jews, being born in the Former Soviet Union, the Middle East and North Africa, vs. Israel and the Americas, was positively associated with CagA sero-positivity. In both populations, sibship size was positively associated with both CagA positive and negative phenotypes; and education was inversely associated. In conclusion, CagA positive and negative infection had similar correlates, suggesting shared sources of these two H. pylori phenotypes.

Smoking and Helicobacter pylori infection: an individual participant pooled analysis (Stomach Cancer Pooling- StoP Project)

Smoking has been associated with acquisition and increased persistence of Helicobacter pylori infection, as well as with lower effectiveness of its eradication. A greater prevalence of infection among smokers could contribute to the increased risk for gastric cancer. We aimed to estimate the association between smoking and seropositivity to H. pylori through an individual participant data pooled analysis using controls from 14 case-control studies participating in the Stomach Cancer Pooling Project. Summary odds ratios and prevalence ratios (PRs), adjusted for age, sex and social class, and the corresponding 95% confidence intervals (CIs) were estimated through random-effects meta-analysis. Heterogeneity was quantified using the I statistic and publication bias with Egger's test. There was no significant association between smoking (ever vs. never) and H. pylori seropositivity (adjusted odds ratio = 1.08; 95% CI: 0.89-1.32; adjusted PR = 1.01; 95% CI: 0.98-1.05). The strength of the association did not increase with the intensity or duration of smoking; stratified analyses according to sex, age, region or type of sample did not yield a consistent pattern of variation or statistically significant results, except for participants younger than 55 years and who had been smoking for more than 30 years (adjusted PR = 1.08; 95% CI: 1.02-1.15). This is the first collaborative analysis providing pooled estimates for the association between smoking and H. pylori seropositivity, based on detailed and uniform information and adjusting for major covariates. The results do not support an association between smoking and H. pylori infection.

Prevalence and Risk Factors of Helicobacter pylori Infection among Children Aged 1 to 15 Years at Holy Innocents Children's Hospital, Mbarara, South Western Uganda

Background

Helicobacter pylori infection affects more than half of the world's population. The infection is generally acquired during childhood but can remain asymptomatic, with long-term clinical sequelae including gastritis, peptic ulcer disease, and stomach cancer.

Methods

The study was approved by Institutional Review Committee of Mbarara University of Science and Technology. After obtaining informed consent from parents/legal guardians, illegible children who presented with gastrointestinal complaints at Holy Innocents Children's Hospital were recruited; structured questionnaires were administered to the parents/guardians to collect information on sociodemographic data and risk factors of H. pylori infection. Four (4) millilitres of blood was collected from each child and tested for H. pylori blood Antibody test and stool specimens were used for H. pylori antigen test.

Results

The prevalence of H. pylori infection among the study participants was 24.3%. The infection rate increased with increase in age of the participants, from 16.2% among 1to 5 years old to 27.2% among 6 to 10 years. Infections were higher among school going children (68/74, p=0.003, OR 3.9; CI: 1.5 to 10.6) and children from crowded households (59/74, p<0.001, OR 2.6, and CI 1.3 to 5.0), unsafe source of drinking water at schools (46/74, p=0.003), and lack of sanitary facility at homes (57/74, p=0.001, and OR 1.6 CI 0.7 to 3.6).

Conclusion

The prevalence of H. pylori infection among children aged 1 to 15 years at Holy Innocents Children's Hospital was high and increases with age. School attendance, lack of sanitary facility, lack of safe drinking water, and overcrowding were the risk factors associated with H. pylori infection.

Helicobacter pylori and enteric parasites co-infection among diarrheic and non-diarrheic Egyptian children: seasonality, estimated risks, and predictive factors

Helicobacter pylori (H. pylori) and intestinal parasites are known for their high prevalence in children. Both of them infect the gastrointestinal tract with overlapping clinical pictures. This study was conducted to determine H. pylori prevalence and its association with intestinal parasites in children, moreover to estimate risk and predictive factors for their detection in stool samples. Single fecal samples were collected from 226 Egyptian pediatric patients (125 diarrheic and 101 non-diarrheic) attending gastroenterology outpatients' clinics, from February 2016 to June 2017. All stool specimens were microscopically examined to search for ova and parasites. Copro-DNAs detection of H. pylori and Cryptosporidium were performed using nested-PCR assays. H. pylori was detected molecularly in 36.8% of the total study population, with a higher prevalence in diarrheic than in non-diarrheic children. Intestinal parasites were detected in 27.4% of the total study populations, of these, 43.9% had co-existence with H. pylori colonized patients and was significantly associated with Cryptosporidium spp. and G. intestinalis. Estimated risk of the presence of H. pylori was in January. Our data provide a better understanding of the epidemiology of H. pylori infection when associated with intestinal parasites. H. pylori co-existence with G. intestinals and Cryptosporidium may suggest the association of H. pylori infection with markers of fecal exposure. Whether H. pylori provides favorable conditions for intestinal parasitosis or vice versa, still further investigations are needed with an emphasis upon determining correlation with gut microbiomes.

Prevalence of Helicobacter pylori in asymptomatic patients at surgical outpatient department: Harare hospitals

Background

Helicobacter pylori infection is present in more than 50% of the world's population. The estimated life time risk of peptic ulcer disease is 20 percent and of gastric cancer is 1–2 percent.

Materials and methods

A cross sectional study was done at two Central hospitals in Harare, Zimbabwe, with the objective being to estimate the prevalence of Helicobacter pylori infection in asymptomatic individuals. Other objectives were to determine the association of the Helicobacter pylori infection with potential risk factors.

Four hundred and fifty patients visiting the outpatient surgical clinics for other complaints other than upper gastrointestinal symptoms were recruited in the study. Drops of whole blood were obtained by fingertip puncture from each patient. The Onsite H. pylori Combo Rapid Test was used to confirm the presence or absence of antibodies against Helicobacter pylori. A questionnaire was used to record the sociodemographics of the participants.

Results

Three hundred patients, 186 males (62%) and 114 females (38%) participated. The prevalence of Helicobacter pylori infection was 67.7 percent (203/300). The prevalence of H pylori infection was significantly correlated with increasing age (p = 0.012), sharing of a bed with siblings during childhood (p = 0.013) and the mode of sanitation methods (p = 0.023). There was no association found between H pylori infection and other risk factors such as; gender, level of education, employment status or number of rooms in a house.

Conclusion

H. pylori infection prevalence was significantly associated with increasing age, sharing of a bed with siblings during childhood and the mode of sanitation used. Clinicians and the public have to be aware of the important role of H pylori in upper gastrointestinal disease. Use of better sanitation methods, appropriate hygiene, avoidance of over-crowding amongst other measures should be encouraged as a means to reduce the acquisition and transmission of H pylori.

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Prevalence of H. pylori infection is 67.7%.

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The results are from Zimbabwe.

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It is associated with increasing age and the mode of sanitation.

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It is associated with sharing of a bed with siblings during childhood.

Potential risk factors and prevalence of Helicobacter pylori infection among adult patients with dyspepsia symptoms in Cameroon

BACKGROUND

Helicobacter pylori is a Gram negative bacterium that colonizes the stomach of approximately two-thirds of the human population and it is involved in the pathogenesis of gastroduodenal diseases. This study sought to determine potential risk factors associated with seroprevalence of H. pylori among dyspepsia patients in Cameroon for a better management of the disease.

METHODS

The study was carried out from August to December 2014 at Laquintinie Hospital and District Hospital of Bonassama in Douala metropolis. 205 patients (127 women and 78 men; mean age, 53.79 ± 11.11 years; range, 35-75 years) were enrolled. Each subject gave a written consent. The study was approved by the local Ethical Committee of Medical Sciences. A structured questionnaire was used to collect information on sociodemographic parameters and predisposing risk factors for Helicobacter pylori infection. For each patient, body mass index (BMI) and direct inquiry about dyspeptic symptoms were done. Blood samples were tested for H. pylori antibodies, and ABO/Rhesus blood group antigen typing was performed.

RESULTS

The overall prevalence was 64.39%. All patients with upper abdominal pains and frequent burping were H. pylori seropositive. We found that infection takes place early in childhood and adolescence, and reaches its peak at adulthood at 35 to 44 years. Sixty-two percent of women over 68 of men were infected. 80.39% of patients with family history of gastric cancer were seropositive, while 19.60% were seronegative (p = 0.001). Prevalence of 79.09 and 47.4% was recorded respectively for subjects with low, middle and high income levels (p = 0.001). H. pylori infection rate was 60.48% in blood group O patients compared with 70.37% in other blood groups (p = 0.203). 73% of infected subjects over 59% of uninfected ones currently take NSAIDs (p = 0.0509). Overcrowded households have a higher rate of 65.32% seropositivity in contrast with a lower rate of 33.33% from norm household (p = 0.197). 69.29% of obese and overweight patients versus 58.24% of subjects with normal weight were seropositive (P = 0.215).

CONCLUSION

The results of this study demonstrate that low income, family history of gastric cancer, clinical symptoms of nausea/vomiting and flatulence/bloating were risk factors of H. pylori infection in this population.

Factors associated with uninvestigated dyspepsia in students at 4 Latin American schools of medicine: A multicenter study

INTRODUCTION AND AIMS

Dyspepsia is a multifactorial disease that can involve alcohol, tobacco, or nonsteroidal anti-inflammatory drug use, as well as lifestyle, diet, socioeconomic elements, or psychologic factors. The aim of the present article was to establish the frequency of uninvestigated dyspepsia and determine its associated factors in students at 4 Latin American schools of medicine.

MATERIALS AND METHODS

A cross-sectional, analytic study was conducted, in which a survey made up of closed-ended questions was applied at just one point in time. The association between the variables was then analyzed. A new questionnaire for the diagnosis of dyspepsia was one of the tests utilized to diagnose uninvestigated dyspepsia. Generalized linear models were used for the bivariate and multivariate analyses, employing the Poisson model with the log link function, obtaining crude prevalence ratios, adjusted prevalence ratios, and their 95% confidence intervals.

RESULTS

Of the 1,241 individuals surveyed, 54% (841) were females and the median age was 21 years (range: 19-23 years). Prevalence of uninvestigated dyspepsia was 46%. The factors that had a direct association with dyspepsia were: depression, difficulty sleeping, and coffee consumption. On the contrary, eating regularly in a boarding house and the male sex had an inverse association.

CONCLUSIONS

Uninvestigated dyspepsia frequency was high in students at 4 Latin American schools. Depression, difficulty sleeping, and steady coffee drinking were factors directly associated with dyspepsia, whereas male sex and eating out at regular hours were factors with a reverse association. Therefore, we recommend that universities implement early detection programs for this highly preventable pathology.

A cohort study on Helicobacter pylori infection associated with nonalcoholic fatty liver disease

BACKGROUND

Previous studies have suggested a link between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD), yet large-scale longitudinal studies are lacking to elucidate this association.

METHODS

A cohort study of 17,028 adults without NAFLD at baseline, who participated in a repeated health screening examination including an H. pylori-specific immunoglobulin G antibody test, was conducted to evaluate the association between H. pylori and NAFLD development. Fatty liver was diagnosed by ultrasonography.

RESULTS

During the 83,130 person-years follow-up, participants with H. pylori infection had a higher rate of incident NAFLD than those who were uninfected. In a multivariable model adjusted for age, sex, body mass index, smoking status, alcohol intake, regular exercise, year of screening exam, and education level, the hazard ratio (HR) for NAFLD development in participants with H. pylori infection compared to those without infection was 1.21 [95% confidence interval (CI), 1.10-1.34]. The association persisted after further adjustment for metabolic variables, inflammatory marker, and liver enzymes. The association between H. pylori and NAFLD was still evident in an analysis using fatty liver index as a surrogate marker of NAFLD. In addition, the association between H. pylori infection and incident NAFLD did not differ across clinically relevant subgroups evaluated.

CONCLUSIONS

H. pylori infection was significantly associated with the development of NAFLD, independent of metabolic and inflammatory risk factors. H. pylori infection may play a pathophysiologic role in NAFLD development, indicating that H. pylori eradication might play a role in reducing the risk of NAFLD.

Is There a Link Between H. Pylori and the Epidemiology of Crohn's Disease?

INTRODUCTION

Case control studies suggest an inverse association between Helicobacter pylori (H. pylori) and Crohn's disease (CD). It is possible this could be accounted for by confounders such as antibiotic therapy. Analyzing the geographic distribution of H. pylori and the links with the incidence and prevalence of CD would be an alternative approach to circumvent these confounders.

METHODS

The literature was searched for studies published between 1990 and 2016 that reported incidence or prevalence data for CD in random population samples in developed countries (GDP per capita >20,000 USD/year). Corresponding prevalence studies for H. pylori in these same regions were then sought matched to the same time period (±6 years). The association between the incidence and prevalence of CD and H. pylori prevalence rates were assessed before and after adjusting for GDP and life expectancy.

RESULTS

A total of 19 CD prevalence and 22 CD incidence studies from 10 European countries, Japan, USA, and Australia with date-matched H. pylori prevalence data were identified. The mean H. pylori prevalence rate was 43.4% (range 15.5-85%), and the mean rates for incidence and prevalence for CD were 6.9 and 91.0/100,000 respectively. The incidence (r = -0.469, p < 0.03) and prevalence (r = -0.527, p = 0.02) of CD was inversely and significantly associated with prevalence of H. pylori infection.

CONCLUSIONS

Our data demonstrate a significant inverse association between geographic distribution of H. pylori and CD. Thus, it is highly unlikely that the findings of previous case control studies were simply due to confounding factors such as concomitant antibiotic use in CD patients.

Demographic and socioeconomic influences on Helicobacter pylori gastritis and its pre-neoplastic lesions amongst US residents

BACKGROUND

Gastric infection with Helicobacter pylori (Hp) can lead to chronic inactive gastritis, atrophy and intestinal metaplasia.

AIMS

To investigate in a cross-sectional study these changes among different socioeconomic and ethnic groups within the USA.

METHODS

We used the Miraca Life Sciences database, an electronic depository of clinicopathological records from patients distributed throughout the USA, to extract data from 487 587 patients who underwent oesophago-gastro-duodenoscopy with biopsy between 1/2008 and 12/2014. We then classified patients into ethnic and socioeconomic categories using previously validated algorithms, as well as ZIP code-based information derived from the 2011-2012 US Census.

RESULTS

The prevalence of Hp increased significantly until the age-group 40-49, before it leveled off and started a gradual decrease. The prevalence of chronic inactive gastritis, atrophy, and intestinal metaplasia increased significantly with age. The prevalence of Hp, chronic inactive gastritis, intestinal metaplasia, and atrophy decreased significantly with the percentage of Whites per ZIP code. The prevalence of all four diagnoses also decreased significantly with rising levels of income or college education. Hp, chronic inactive gastritis, atrophy and intestinal metaplasia were more common among Hispanics and the influence of income or college education less pronounced than in the entire population. Hp, chronic inactive gastritis, atrophy, and intestinal metaplasia were also more common among East-Asians, Hp and atrophy decreasing with rising income but remaining unaffected by levels of college education.

CONCLUSION

Ethnicity and socioeconomic factors influence the occurrence of Hp gastritis, and its progression to chronic inactive gastritis, atrophy or intestinal metaplasia.

Association between genetic variants in the XPG gene and gastric cancer risk in a Southern Chinese population

Xeroderma pigmentosum group G (XPG) recognizes and excises DNA damage on the 3' side during the DNA repair process. Previous studies indicated that XPG gene polymorphisms may associate with gastric cancer susceptibility, but results were inconsistent. We evaluated the association of five potentially functional XPG polymorphisms (rs2094258 C>T, rs751402 C>T, rs2296147 T>C, rs1047768 T>C, and rs873601 G>A) with gastric cancer susceptibility in 1142 gastric cancer cases and 1173 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models. Overall, no significant association was detected between any of selected polymorphism and gastric cancer risk. However, we found that individuals carrying 3-4 risk genotypes were at significantly higher risk of gastric cancer than those with 0-2 risk genotypes (OR=1.32, 95% CI=1.04-1.68, P=0.021). The stratification analysis revealed that the cumulative effect of risk genotypes (3-4 vs. 0-2) on gastric cancer were more prominent among subgroups older than 58 years and men. In conclusion, our results indicated that none of the selected XPG polymorphism could significantly alter gastric cancer susceptibility alone. These polymorphisms might collectively confer increased gastric cancer susceptibility. These findings would be strengthened by larger prospective multicenter studies involving different ethnic populations.

Helicobacter pylori is associated with dyslipidemia but not with other risk factors of cardiovascular disease

Epidemiologic and clinical data suggest that Helicobacter pylori infection is a contributing factor in the progression of atherosclerosis. However, the specific cardiovascular disease risk factors associated with H. pylori remain unclear. We performed a cross-sectional study of 37,263 consecutive healthy subjects who underwent a routine health check-up. In multivariable log Poisson regression models adjusted for potential confounders, the associations of H. pylori seropositivity with higher LDL-C (relative risk [RR], 1.21; 95% confidence interval [CI], 1.12–1.30) and lower HDL-C level (RR, 1.10; 95% CI, 1.01–1.18) were significant and independent. In multiple linear regression analyses, H. pylori infection was significantly associated with higher total cholesterol level (coefficient = 2.114, P < 0.001), higher LDL-C level (coefficient = 3.339, P < 0.001), lower HDL-C level (coefficient = −1.237, P < 0.001), and higher diastolic blood pressure (coefficient = 0.539, P = 0.001). In contrast, H. pylori infection was not associated with obesity-related parameters (body mass index, waist circumference), glucose tolerance (fasting glucose, glycated hemoglobin), and systolic blood pressure. We found that H. pylori infection was significantly and independently associated with dyslipidemia, but not with other cardiometabolic risk factors, after adjusting for potential risk factors of atherosclerosis.

Additive interactions between PRKAA1 polymorphisms and Helicobacter pylori CagA infection associated with gastric cancer risk in Koreans

Although several studies reported genetic polymorphisms in protein kinase AMP‐activated alpha 1 catalytic subunit (PRKAA1) and their associations with gastric cancer risk, few have evaluated associations between Helicobacter pylori infection and PRKAA1 gene‐environment interactions. Here, we evaluated the effects of interactions between H. pylori infection and PRKAA1 polymorphisms on gastric cancer risk in Koreans. In this hospital‐based case–control study, PRKAA1 genotypes were analyzed and H. pylori infection and CagA status were examined using a serologic method in 846 pairs of gastric cancer patients and controls matched for age and sex. H. pylori seropositivity was associated with a 1.43‐fold [95% confidence interval: 1.12–1.81] increase in the risk of gastric cancer, and CagA low‐positive titers during H. pylori infection increased the risk by 1.85‐fold (95% confidence interval, 1.38–2.48). Significant positive interaction between the PRKAA1 rs13361707 genotype and H. pylori infection was verified on an additive scale [relative excess risk due to interaction, 0.55; 95% confidence interval, 0.05–1.04; P = 0.030], and the gene‐environment interaction between PRKAA1 rs13361707 and CagA status was also statistically significant (relative excess risk due to interaction, 0.50; 95% confidence interval, 0.30–0.70; P < 0.001). Our results indicated that H. pylori infection, CagA status, and PRKAA1 polymorphisms were risk factors for gastric cancer in Koreans, and that the combination of two of these factors rather than their independent effects synergistically increased the risk.

Early life socioeconomic position and immune response to persistent infections among elderly Latinos

Persistent infections, such as cytomegalovirus (CMV), herpes simplex virus-1 (HSV-1), Helicobacter pylori (H. pylori), and Toxoplasma gondii (T. gondii), are common in the U.S. but their prevalence varies by socioeconomic status. It is unclear if early or later life socioeconomic position (SEP) is a more salient driver of disparities in immune control of these infections. Using data from the Sacramento Area Latino Study on Aging, we examined whether early or later life SEP was the strongest predictor of immune control later in life by contrasting two life course models, the critical period model and the chain of risk model. Early life SEP was measured as a latent variable, derived from parental education and occupation, and food availability. Indicators for SEP in later life included education level and occupation. Individuals were categorized by immune response to each pathogen (seronegative, low, medium and high) with increasing immune response representing poorer immune control. Cumulative immune response was estimated using a latent profile analysis with higher total immune response representing poorer immune control. Structural equation models were used to examine direct, indirect and total effects of early life SEP on each infection and cumulative immune response, controlling for age and gender. The direct effect of early life SEP on immune response was not statistically significant for the infections or cumulative immune response. Higher early life SEP was associated with lower immune response for T. gondii, H. pylori and cumulative immune response through pathways mediated by later life SEP. For CMV, higher early life SEP was both directly associated and partially mediated by later life SEP. No association was found between SEP and HSV-1. Findings from this study support a chain of risk model, whereby early life SEP acts through later life SEP to affect immune response to persistent infections in older age.

European Code against Cancer 4th Edition: Infections and Cancer

Of the 2,635,000 new cancer cases (excluding non-melanoma skin cancers) occurring in the European Union (EU) in 2012, it is estimated that approximately 185,000 are related to infection with human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV), and Helicobacter pylori (H. pylori). Chronic infection with these agents can lead to cancers of the cervix uteri, liver, and stomach, respectively. Chronic infection with HCV can also lead to B-cell non-Hodgkin lymphoma. Human immunodeficiency virus (HIV) infection continues to be of major public health importance in several EU countries and increases cancer risk via HIV-induced immunosuppression. The fourth edition of the European Code Against Cancer presents recommendations on effective and safe preventive interventions in order to reduce the risk of infection-related cancers in EU citizens. Based on current available evidence, the fourth edition recommends that parents ensure the participation of their children in vaccination programs against HBV (for newborns) and HPV (for girls). In the 'Questions and Answers' (Q&As) section about vaccination and infections in the website for the European Code Against Cancer, individuals who are at risk of chronic HBV or HCV are advised to seek medical advice about testing and obtaining treatment when appropriate. Individuals most at risk of HIV are advised to consult their doctor or healthcare provider to access counselling and, if needed, testing and treatment without delay. Information about H. pylori testing and treatment is also provided as testing might currently be offered in some high-risk areas in Europe. The rationale and supporting evidence for the recommendations on vaccination in the European Code Against Cancer, and for the main recommendations on vaccination and infection in the Q&As, are explained in the present review.

Alcohol intake and Helicobacter pylori infection: a dose-response meta-analysis of observational studies

Background Alcohol intake has been suggested to have an impact on the development of many chronic diseases. How alcohol intake may modulate risk of Helicobacter pylori (H. pylori) infection, however, remains a subject open for investigation. A dose-response meta-analysis was performed of epidemiological studies to better quantify this relationship. Materials and methods Twelve observational articles were identified. The summary odds ratio (OR) and confidence intervals (CI) were calculated for alcohol drinkers vs non-drinkers. The summary OR estimates were obtained using the random-effects model and dose-response meta-analysis. Sub-group and sensitivity analysis were also conducted. Results The summary OR was 0.78 (95% CI = 0.69-0.89). The dose-response analysis demonstrated that for drinkers of 10, 15, 30, 60 and 96 g/day alcohol intake, the estimated ORs were 0.80 (95% CI = 0.76-0.85), 0.79 (95% CI = 0.75-0.84), 0.83 (95% CI = 0.78-0.87), 0.85 (95% CI = 0.78-0.93) and 0.87 (95% CI = 0.70-1.06), respectively, compared to non-drinkers. The inverse relationship between alcohol intake and H. pylori infection was consistent, regardless of sex, age, geographic areas, detection methods or beverage types.

CONCLUSION

Evidence from these observational studies suggests that moderate alcohol intake is associated with a reduction in H. pylori infection of ∼ 22% and may facilitate elimination of H. pylori.

Preoperative Helicobacter pylori Infection is Associated with Increased Survival After Resection of Gastric Adenocarcinoma

BACKGROUND

Limited data exist on the prognosis of preoperative Helicobacter pylori (H. pylori) infection in gastric adenocarcinoma (GAC).

METHODS

Patients who underwent curative-intent resection for GAC from 2000 to 2012 at seven academic institutions comprising the United States Gastric Cancer Collaborative were included in the study. The primary end points of the study were overall survival (OS), recurrence-free survival (RFS), and disease-specific survival (DSS).

RESULTS

Of 559 patients, 104 (18.6 %) who tested positive for H. pylori were younger (62.1 vs 65.1 years; p = 0.041), had a higher frequency of distal tumors (82.7 vs 71.9 %; p = 0.033), and had higher rates of adjuvant radiation therapy (47.0 vs 34.9 %; p = 0.032). There were no differences in American Society of Anesthesiology (ASA) class, margin status, grade, perineural invasion, lymphovascular invasion, nodal metastases, or tumor-node-metastasis (TNM) stage. H. pylori positivity was associated with longer OS (84.3 vs 44.2 months; p = 0.008) for all patients. This relationship with OS persisted in the multivariable analysis (HR 0.54; 95 % CI 0.30-0.99; p = 0.046). H. pylori was not associated with RFS or DSS in all patients. In the stage 3 patients, H. pylori was associated with longer OS (44.5 vs 24.7 months; p = 0.018), a trend of longer RFS (31.4 vs 21.6 months; p = 0.232), and longer DSS (44.8 vs 27.2 months; p = 0.034).

CONCLUSIONS

Patients with and without preoperative H. pylori infection had few differences in adverse pathologic features at the time of gastric adenocarcinoma resection. Despite similar disease presentations, preoperative H. pylori infection was independently associated with improved OS. Further studies examining the interaction between H. pylori and tumor immunology and genetics are merited.

Antimicrobial susceptibility of Canadian isolates of Helicobacter pylori in Northeastern Ontario

BACKGROUND

Helicobacter pylori plays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years.

OBJECTIVE

To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance.

METHODS

Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20 H pylori isolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance.

RESULTS

Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment of H pylori infections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA and gyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance.

CONCLUSIONS

In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs of H pylori antibiotic resistance may need to be revisited or improved to prevent antimicrobial therapy failure.

Review article: the epidemiology and prevention of gastric cancer

BACKGROUND

Gastric cancer can be divided into cardia and noncardia gastric adenocarcinoma (NCGA). Non cardia gastric cancer is a disease that has declined in global incidence but has remained as an extremely lethal cancer.

AIM

To review recent advances in epidemiology and strategies in prevention of non cardia gastric cancer.

METHODS

A rapid literature search strategy was developed for all English language literature published before March 2013. The search was conducted using the electronic databases PubMed and EMBASE. The search strategy included the keywords 'stomach neoplasms', 'gastric cancer', 'epidemiology', 'risk factor', 'early detection of cancer', 'mass screening', 'cancer burden', 'prevention' and 'cost-effectiveness'. The search strategy was adjusted according to different requirements for each database. The specific search was also performed in cancer-related websites for country-specific information. The search was limited to past 10 years.

RESULTS

Gastric cancer is the fifth most common cancer but the third leading cause of cancer death. The case fatality rate is 75%. Screening by radiological or endoscopic methods has limited success in prevention of gastric cancer. Helicobacter pylori has been identified as a carcinogen, accounting for 60-70% of gastric cancer globally and eradication is a potential preventive measure. A meta-analysis in 2009 demonstrated that individuals treated with H. pylori eradication therapy can reduce gastric cancer risk. The extended Shandong Intervention trial that lasted 14.3 years showed that H. pylori eradication therapy significantly reduced gastric cancer incidence by 39%. Consensus groups from Asia, Europe and Japan have recommended H. pylori eradication as primary prevention in high-risk areas. Following eradication therapy, endoscopic surveillance of pre-malignant lesions using enhanced imaging appears to be another promising preventive strategy.

CONCLUSIONS

Gastric cancer remains a major diagnostic and therapeutic challenge. There is emerging evidence that H. pylori eradication in high gastric cancer regions can lead to a decline in the incidence of this highly lethal disease.

Review article: Associations between Helicobacter pylori and obesity--an ecological study

BACKGROUND

There is emerging debate over the effect of Helicobacter pylori infection on body mass index (BMI). A recent study demonstrated that individuals who underwent H. pylori eradication developed significant weight gain as compared to subjects with untreated H. pylori colonisation.

AIM

To elucidate the association between H. pylori colonisation and the prevalence of overweight and obesity in developed countries.

METHODS

The literature was searched for publications reporting data on H. pylori prevalence rates and obesity prevalence rates. Studies selected reported H. pylori prevalence in random population samples with sample sizes of more than 100 subjects in developed countries (GDP >25,000 US$/person/year). Corresponding BMI distributions for corresponding countries and regions were identified. Nonparametric tests were used to compare the association between H. pylori and overweight and obesity rates.

RESULTS

Forty-nine studies with data from 10 European countries, Japan, the US and Australia were identified. The mean H. pylori rate was 44.1% (range 17-75%), the mean rates for obesity and overweight were 46.6 (± 16)% and 14.2 (± 8.9)%. The rate of obesity and overweight were inversely and significantly (r = 0.29, P < 0.001) correlated with the prevalence of H. pylori infection.

CONCLUSIONS

There is an inverse correlation between H. pylori prevalence and rate of overweight/obesity in countries of the developed world. Thus, the gradual decrease of the H. pylori colonisation that has been observed in recent decades (or factors associated with decrease of) could be causally related to the obesity endemic observed in the Western world.