A community-based seroepidemiologic study of Helicobacter pylori infection in Mexico

Frequency of Helicobacter pylori in Patients With Rheumatoid Arthritis Whose Methotrexate Was Stopped Due to Gastrointestinal Intolerance

OBJECTIVE

The aims of this study were to compare the frequency of Helicobacter pylori between patients with rheumatoid arthritis (RA) with and without methotrexate (MTX)-related gastrointestinal system (GIS) intolerance, and to demonstrate the associated factors with such intolerance.

METHODS

The data of 9756 patients with RA who presented between January 2011 and December 2020 were evaluated. Methotrexate-related GIS intolerance was defined as the discontinuation of MTX owing to the dyspeptic symptoms despite supportive measures and was detected in 1742 (31.3%) patients among 5572 MTX users. A total of 390 patients with and without intolerance who had at least 1 gastroscopic evaluation were included in the final analyses. The demographic, clinical, laboratory, and pathologic characteristics of patients with and without MTX-related GIS intolerance were compared. To determine the associated factors with MTX-related GIS intolerance, logistic regression analysis was performed.

RESULTS

Of 390 patients, 160 (41.0%) patients had MTX-related GIS intolerance. According to the pathology results, the presence of H. pylori , inflammation, and activity were significantly higher in patients with MTX-related GIS intolerance ( p < 0.001 for each comparison). In multivariable logistic regression analysis, the use of biologic disease-modifying antirheumatic drugs (DMARDs) or targeted synthetic DMARDs was found to be an independently associated factor for MTX-related GIS intolerance (odds ratio [OR], 3.03 for model 1; OR, 3.02 for model 2) in addition to H. pylori presence (OR, 9.13 for model 1; OR, 5.71 for model 2).

CONCLUSIONS

In this study, we found that the presence of H. pylori and the use of biologic or targeted synthetic DMARDs were associated with MTX-related GIS intolerance.

Thin Layer Immunoassay: An Economical Approach to Diagnose Helicobacter pylori Infection in Gastroduodenal Ulcer Disease Patients of Pakistan, a Comparative Analysis

Helicobacter pylori is a causative agent of gastritis, gastroduodenal ulcers and gastric adenocarcinoma. The majority of H. pylori-associated patients live in underdeveloped areas, facing the problem of lack of proper diagnostic facility. Hence, a simple and economical assay is required to handle the majority of gastric patients. Serum samples from gastroduodenal ulcers and gastritis patients were screened for H. pylori infection by thin layer immunoassay. A polystyrene plate coated with H. pylori sonicate whole cell antigen (10 µg/mL). Two-fold diluted patient's serum was allowed to react at 37 °C, incubated at 60 °C for 1 min over a water bath and the water condensation pattern for the H. pylori antibody was recorded. ELISAs were used as reference assays to evaluate the efficacy of the developed thin layer immunoassay (TLI). Gastric patients' blood samples (62% male and 6% female) tested positive for H. pylori, while age-wise, 15-25-year-old males (36%) and 65-75-year-old females (50%) showed the highest number of H. pylori infections. TLI showed sensitivity (72-67%), specificity (100%), accuracy (94-69%) and κ value (0.493-0.357) in comparison with wELISA (Surface whole cell ELISA), sELISA (sonicate whole cell ELISA) and kELISA (commercial KIT ELISA). We conclude that thin layer immunoassay is a low cost, fast, simple and clinically reliable method for H. pylori diagnosis at initial stages in patients in under-developed countries.

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.

Ethnic Disparities in Early-Onset Gastric Cancer: A Population-Based Study in Texas and California

BACKGROUND

Incidence rates of gastric cancer are increasing in young adults (age &lt;50 years), particularly among Hispanic persons. We estimated incidence rates of early-onset gastric cancer (EOGC) among Hispanic and non-Hispanic White persons by census tract poverty level and county-level metro/nonmetro residence.

METHODS

We used population-based data from the California and Texas Cancer Registries from 1995 to 2016 to estimate age-adjusted incidence rates of EOGC among Hispanic and non-Hispanic White persons by year, sex, tumor stage, census tract poverty level, metro versus nonmetro county, and state. We used logistic regression models to identify factors associated with distant stage diagnosis.

RESULTS

Of 3,047 persons diagnosed with EOGC, 73.2% were Hispanic White. Incidence rates were 1.29 [95% confidence interval (CI), 1.24-1.35] and 0.31 (95% CI, 0.29-0.33) per 100,000 Hispanic White and non-Hispanic White persons, respectively, with consistently higher incidence rates among Hispanic persons at all levels of poverty. There were no statistically significant associations between ethnicity and distant stage diagnosis in adjusted analysis.

CONCLUSIONS

There are ethnic disparities in EOGC incidence rates that persist across poverty levels.

IMPACT

EOGC incidence rates vary by ethnicity and poverty; these factors should be considered when assessing disease risk and targeting prevention efforts.

Gastric adenocarcinoma in the excluded stomach 18 years after bariatric surgery: a case report

Gastric cancer (GC) ranks fourth in overall cancer mortality. Bariatric surgical procedures, especially the gastric bypass surgery (GBS), raise a concern about the risk of GC in the excluded stomach (ES). Diagnosis of GC in the ES is challenging due to anatomical changes and impossibility of endoscopic access to the ES. There are few reports of GC after GBS, and it occurs more in the gastric stump than in the ES. We report a case of a 54-year-old female with GC in the ES 18 years after GBS. The increasing number of GBS and the aggressiveness of the GC show how relevant this case is to emphasize the need to consider this diagnosis in patients who develop upper abdominal symptoms, anemia or weight loss.

The Relationship between Anemia and Helicobacter Pylori Infection in Children

(1) Background: Many studies suggest that Helicobacter pylori (H. pylori) infection is associated with a higher prevalence of anemia. The aim of this study is to explore this fact for a pediatric population from the northeast of Romania; (2) Methods: A correlational retrospective study between infection with H. pylori and anemia was performed on a group of 542 children in a pediatric gastroenterology regional center in Northeast Romania; (3) Results: Out of 542 children with confirmed H. pylori infection, microcytic hypochromic anemia was present in 48 children, of whom 7 (14.5%) also had iron deficiency.; (4) Conclusions: The study results demonstrate a significant association of H. pylori infection with iron-deficiency anemia and iron deficiency in children in accordance with the results established in the published literature. Although the direct relationship between them it is not clear yet, prevention represents one of the first clinical measures that need to be implemented when encountering a refractory moderate to severe iron-deficiency anemia and, especially, when associated with gastrointestinal tract symptoms.

Helicobacter pylori infection and DNMT3a polymorphism are associated with the presence of premature coronary artery disease and subclinical atherosclerosis. Data from the GEA Mexican Study

BACKGROUND

The association between H. pylori infection and coronary artery disease (CAD) is well-known. Alterations in DNA methylation in CAD have been reported, which can be induced by H. pylori through the DNA demethylases (DNMTs). The objective was to analyze the association and interaction of H. pylori infection and DMNT3a gene polymorphisms with premature CAD (pCAD) and subclinical atherosclerosis (SA).

METHODS

The study included 561 patients with pCAD, 318 subjects with SA, and 599 healthy controls. Antibodies against H. pylori and DNMT3a rs13420827, rs752208, and rs1550117 polymorphisms were determined.

RESULTS

The pCAD group presented the highest seroprevalence of H. pylori infection (87.7%) compared to the SA (74.5%, p = 1 × 10^-6) and the control group (63.1%, p = 7 × 10^-23). A significant association was observed between H. pylori infection and pCAD (OR = 2.729, p = 1.0 × 10^-6). The rs13420827 polymorphism was associated with a high risk of H. pylori infection in the whole population (p_additive = 0.009, p_dominant = 0.018, and p_codominant2 = 0.013) and in individuals with SA (p_additive = 0.003, p_dominant = 0.020, p_recessive = 0.013, and p_codominant2 = 0.005). The coexistence of H. pylori infection and the rs13420827GG genotype increases the risk of pCAD (p_interaction = 1.1 × 10^-5).

CONCLUSIONS

According to the model adjusted for more confounding variables, H. pylori infection was associated with almost three times the risk of developing pCAD. The rs13420827G allele was associated with an increased risk of H. pylori infection in the whole population and in individuals with SA. Individuals in whom H. pylori infection and the rs13420827GG genotype coexist are at increased risk of pCAD.

Identifying the Demographic, Clinical, and Endoscopic Findings of Gastroesophageal Reflux Disease in Patients With Helicobacter pylori Infection at King Abdulaziz University Hospital, Jeddah, Saudi Arabia

Background: Helicobacter pylori (H. pylori) infection and gastroesophageal reflux disease (GERD) are widely spread clinical terms. GERD refers to the backflow of gastric acid to the esophagus and upper gastrointestinal tract, causing irritation. H. pylori is a gram-negative bacillus that adheres mainly to the gastric mucosa, causing peptic ulcers and gastritis. The nature of the relationship between GERD and H. pylori is yet to be explored, and few studies have been conducted. In contrast, some studies suggest a protective role of H. pylori against GERD. This study aimed to identify the demographic, clinical, and endoscopic findings of patients with GERD who underwent H. pylori testing.

Methods: A retrospective review of medical records at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between 2015 and 2021 was conducted in June 2021. Our sample consisted of 255 individuals enrolled based on age and H. pylori status. In univariate analysis, we used frequency tests for qualitative data and measure of central tendency (MCT) for quantitative data. In bivariate analysis, we used the t-test and Pearson’s chi-square test.

Results: Of 255 GERD patients enrolled, 90 were positive and 165 were negative for H. pylori. The majority were females (54 were positive and 93 were negative for H. pylori). Both groups mainly complained of abdominal pain. Endoscopically, gastritis was higher in the H. pylori-positive group than in the H. pylori-negative group.

Conclusion: In conclusion, the majority of GERD patients were H. pylori-negative, females, Saudis, and non-smokers.

Clinical, endoscopic and histological characteristics of Mexican adult patients with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) has high prevalence/incidence in Western Europe, Canada, United States of America and Australia where it has significantly increased over the past three decades to the extent that some consider it an epidemic.

Colostrum IgA1 antibodies recognize antigens from Helicobacter pylori and prevent cytoskeletal changes in human epithelial cells

Helicobacter pylori is a gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children. This article is protected by copyright. All rights reserved.

Helicobacter pylori prevalence in healthy Mexican children: comparison between two non-invasive methods

Background

Helicobacter pylori detection in asymptomatic children with suspected infection or with symptoms that suggest gastric pathology is problematic, since most of the methods depend on the endoscopic study, an invasive and expensive method. Non-invasive methods can be a feasible alternative but must be validated. The purpose of this study was to evaluate the concordance between H. pylori DNA detection in saliva and dental plaque by PCR, with antigen detection in stool by immunochromatography, among asymptomatic children in the state of Guerrero, Mexico.

Methods

Dental plaque, saliva, and stool samples were obtained from 171 children between 6 and 12 years old. H. pylori detection in saliva and dental plaque was performed by PCR using specific primers for the 16S rRNA gene, while the detection in stool samples was performed by immunochromatography using the CerTest kit.

Results

We found an overall H. pylori prevalence of 59.6% (102/171). Of the H. pylori positive children 18% (20/111) were positive in saliva samples, 28.1% (34/121) in dental plaque samples, and 50.4% (71/141) in stool samples. A higher prevalence was found in girls (64.7%, p = 0.002). Although some of the children declared some dyspeptic symptoms, these were no related to H. pylori. In conclusion, we found a high prevalence of H. pylori in asymptomatic children and the highest proportion was detected by stool antigen test, which was the most feasible method to detect H. pylori infection.

Prevalence and correlates of Helicobacter pylori infection among under-five children, adolescent and non-pregnant women in Nepal: Further analysis of Nepal national micronutrient status survey 2016

Most of the Helicobacter pylori infections occur in developing countries. The risk factors for H. pylori infections are poverty, overcrowding, and unhygienic conditions, which are common problems in under-privileged countries such as Nepal. Despite having a high risk of H. pylori infections, no national level study has been conducted to assess prevalence and correlates of H. pylori infection in Nepal. Therefore, we hypothesized that micronutrients such as iron, vitamin B12 deficiency, socio-economic status, and nutritional status correlate with the prevalence of H. pylori infection in Nepal.

We studied prevalence and correlates of H. pylori infection among under-five children, adolescents aged 10–19 years and married non-pregnant women aged 20–49 years using data from the Nepal National Micronutrient Status Survey 2016 (NNMSS-2016). H. pylori infection was examined in stool of 6–59 months old children and 20–49 years old non-pregnant women whereas the rapid diagnostic kit using blood sample was used among adolescent boys and girls.

Prevalence of H. pylori infection was 18.2% among 6–59 months old children, 14% among adolescent boys and 16% among adolescent girls aged 10–19 years; and 40% among 20–49 years non-pregnant women. Poor socioeconomic status, crowding, and unhygienic condition were found to be positively associated with higher incidence of H. pylori infections. No significant correlation was observed between nutritional and micronutrients status (iron or risk of folate deficiency) with H. pylori infection.

Findings from this study suggest that poverty-associated markers are primary contributors of H. pylori infections in Nepalese communities. To control acquisition and persistence of H. pylori infection in Nepal, we suggest improved management of safe drinking water and implementation of sanitation and hygiene programs, with a focus on those of lower socioeconomic status.

Helicobacter pylori is associated with a wide spectrum of gastrointestinal diseases and is a common problem in tropical region where inter-human contact is the primary mode of disease transmission. Poor socio-economic status is a crucial fueling factor of H. pylori infection. In this study, the authors present data from Nepal national micronutrient status survey 2016 (NNMSS-2016) and investigated the risk factors associated with H. pylori infections among under-five years old children, 10–19 years old adolescent boys and girls, and 20–49 years non-pregnant women nationwide. Study findings corroborate that poverty-associated markers are the key driving factor of H. pylori infections in Nepal, which can have a manifold effect on nutrition and subsequent child growth retardation. Management of safe drinking water and implementation of sanitation and hygiene practices to decrease acquisition of H. pylori infection is a pressing need in rural parts of Nepal and among marginalized communities. The findings of this study highlight the varied prevalence of H. pylori by age group, gender, place of residence, ethnic group, and ecological regions of the country. Moreover, no significant correlation was observed between nutritional and micronutrients status with H. pylori infection.

Residence Time-Extended Nanoparticles by Magnetic Field Improve the Eradication Efficiency of Helicobacter pylori

Helicobacter pylori infection is one of the leading causes of several gastroduodenal diseases, such as gastritis, peptic ulcer, and gastric cancer. In fact, H. pylori eradication provides a preventive effect against the incidence of gastric cancer. Amoxicillin is a commonly used antibiotic for H. pylori eradication. However, due to its easy degradation by gastric acid, it is necessary to administer it in a large dosage and to combine it with other antibiotics. This complexity and the strong side effects of H. pylori eradication therapy often lead to treatment failure. In this study, the chitosan/poly (acrylic acid) particles co-loaded with superparamagnetic iron oxide nanoparticles and amoxicillin (SPIO/AMO@PAA/CHI) are used as drug nano-carriers for H. pylori eradication therapy. In vitro and in vivo results show that the designed SPIO/AMO@PAA/CHI nanoparticles are biocompatible and could retain the biofilm inhibition and the bactericidal effect of amoxicillin against H. pylori. Moreover, the mucoadhesive property of chitosan allows SPIO/AMO@PAA/CHI nanoparticles to adhere to the gastric mucus layer and rapidly pass through the mucus layer after exposure to a magnetic field. When PAA is added, it competes with amoxicillin for chitosan, so that amoxicillin is quickly and continuously released between the mucus layer and the gastric epithelium and directly acts on H. pylori. Consequently, the use of this nano-carrier can extend the drug residence time in the stomach, reducing the drug dose and treatment period of H. pylori eradication therapy.

The University of Zimbabwe College of Health Sciences (UZ-CHS) BIRTH COHORT study: rationale, design and methods

BACKGROUND

Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+), has greatly improved maternal-infant health. Thus, large and increasing numbers of HIV-infected women are on ART during pregnancy, a situation concurrently increasing numbers of HIV-exposed-uninfected (HEU) infants. Compared to their HIV-unexposed-uninfected (HUU) counterparts, HEU infants show higher rates of adverse birth outcomes, mortality, infectious/non-communicable diseases including impaired growth and neurocognitive development. There is an urgent need to understand the impact of HIV and early life ART exposures, immune-metabolic dysregulation, comorbidities and environmental confounders on adverse paediatric outcomes.

METHODS

Six hundred (600) HIV-infected and 600 HIV-uninfected pregnant women ≥20 weeks of gestation will be enrolled from four primary health centres in high density residential areas of Harare. Participants will be followed up as mother-infant-pairs at delivery, week(s) 1, 6, 10, 14, 24, 36, 48, 72 and 96 after birth. Clinical, socio-economic, nutritional and environmental data will be assessed for adverse birth outcomes, impaired growth, immune/neurodevelopment, vertical transmission of HIV, hepatitis-B/C viruses, cytomegalovirus and syphilis. Maternal urine, stool, plasma, cord blood, amniotic fluid, placenta and milk including infant plasma, dried blood spot and stool will be collected at enrolment and follow-up visits. The composite primary endpoint is stillbirth and infant mortality within the first two years of life in HEU versus HUU infants. Maternal mortality in HIV-infected versus -uninfected women is another primary outcome. Secondary endpoints include a range of maternal and infant outcomes. Sub-studies will address maternal stress and malnutrition, maternal-infant latent tuberculosis, Helicobacter pylori infections, immune-metabolomic dysregulation including gut, breast milk and amniotic fluid dysbiosis.

DISCUSSION

The University of Zimbabwe-College of Health-Sciences-Birth-Cohort study will provide a comprehensive assessment of risk factors and biomarkers for HEU infants' adverse outcomes. This will ultimately help developing strategies to mitigate effects of maternal HIV, early-life ART exposures and comorbidities on infants' mortality and morbidity.

TRIAL REGISTRATION

ClinicalTrial.gov Identifier: NCT04087239 . Registered 12 September 2019.

Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

INTRODUCTION AND AIMS

Helicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects.

MATERIALS AND METHODS

In a community survey, a diagnostic ¹³C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25-74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline value, obtained in the ¹³C-urea breath test.

RESULTS

A total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (P<.0001) and the latter was significantly associated with the presence of symptoms (P<.0001).

CONCLUSION

Gastric urease activity was strongly associated with dyspeptic symptoms and cagA+ H. pylori. Elevated ¹³C-delta over baseline values could be used as indicators of a higher risk for gastric disease.

Translation of gastric disease progression at gene level expression

Helicobacter pylori is associated with the development of several lesions in the human stomach. This chronic infection produces gastritis, which can progress to intestinal metaplasia and gastric cancer. To date, there is very little information regarding gene-expression in the different phases of progression caused by chronic H. pylori infection. In this study, we performed a genome-wide gene-expression analysis in gastric biopsies of patients chronically infected with H. pylori, using the potential of high-throughput technologies that have not been fully exploited in this area. Here we illustrate the potential correlation of H. pylori infection with the gene expression changes in follicular gastritis, chronic gastritis and intestinal metaplasia. We also suggest its potential as biomarkers of each condition. An exploratory set of 21 biopsies from patients with follicular gastritis, chronic gastritis, and intestinal metaplasia were analyzed by gene-expression microarrays in order to identify the biological processes altered in each lesion. The microarray data was corroborated by real-time PCR, while 79 Formalin-Fixed Paraffin-Embeded samples were analyzed by immunohistochemistry. Follicular gastritis exhibited significant enrichment in genes associated with glutamate signaling, while chronic gastritis showed a down-regulation in metallothionein 1 and 2 and in oxidative phosphorylation-related genes, which could be associated with the chronic infecton of H. pylori. Intestinal metaplasia exhibited an over-expression of gastrointestinal stem cell markers, such as LGR5 and PROM1, as well as messenger RNA and nucleic acid metabolism-related genes. The gene-expression patterns found in this study provide new comparative information about chronic gastritis, follicular gastritis and intestinal metaplasia that may play an important role in the development of gastric cancer.

Demographics and Clinical and Endoscopic Characteristics of Patients with Helicobacter pylori Infection and Gastroesophageal Reflux Disease: A Case-Control Study

Background

The correlation between Helicobacter pylori (H. pylori) and gastroesophageal reflux disease (GERD) is complex. Some studies showed a protective role of H. pylori infection against GERD. This study was aimed at assessing the role of H. pylori infection in GERD utilizing a large cohort of patients diagnosed with GERD.

Methods and Materials

All patients who underwent gastroscopy for an indication of GERD during the study period between 2015 and 2017 at the EMMS Nazareth Hospital were considered eligible for the study and therefore were included. H. pylori infection was determined by the rapid urease test or histology. Severity of esophagitis was assessed using the Los Angeles classification. Univariate analysis was performed to figure out differences between patients according to H. pylori infection status. Multivariate regression analysis was conducted to illustrate the predictors of positivity for H. pylori infection.

Results

2,508 GERD patients were included with a median age of 49.42 ± 17.96 years. H. pylori infection was detected in 299 (11.9%) patients. GERD patients with H. pylori infection were found to be younger (48.83 ± 17.42 years versus 44.57 ± 17.69 years, p < 0.001), have the tendency to smoke more (1406 (63.6%) versus 266 (89.0%), p < 0.001), and use more proton pump inhibitors or PPIs (1314 (59.5%) versus 242 (80.9%), p < 0.001). In multivariate regression analysis, age (OR 0.987, p < 0.001), smoking status (OR 0.190, p < 0.001), use of ASA/NSAIDs (OR 1.652, p = 0.004), and use of statins (OR 0.499 (95%CI 0.295-0.846), p = 0.010) were found significant among H. pylori-positive individuals. H. pylori-positive subjects have less severe esophagitis and more hiatus hernia.

Conclusion

Patients with GERD and H. pylori infection were significantly younger, tended to smoke more, and used more PPIs and had significantly lower grades of esophagitis compared to noninfected ones.

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.

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.

Clinical and Socio- Demographic Risk Factors for Acquisition of Helicobacter pylori Infection in Nigeria

Background: The aim of the study was to assess clinical and socio-demographic characteristics as well as prior drug usage as risk factors for Helicobacter pylori (H. pylori) infection in Nigeria. Methods: A total of 347 respondents were surveyed by assessing their clinical and socio-demographic characteristics in comparison with the non-invasive gold standard for H. pylori diagnosis, the urea breath test (UBT). Chi-square test and odds ratio analyses were conducted in order to assess if variables such as socio-demographic factors, drug intake, and history of ulcer/gastritis/ gastric cancer within the family significantly predicted test results. Results: A total of 130 (37.5%) respondents were positive for H. pylori by the UBT. Living with more than three people in an apartment and a history of ulcer/gastritis within the family were significantly associated with H. pylori (p ≤0.05), as well as current antibiotic intake (p ≤0.05). Nationality, stay outside Nigeria, level of education, main occupation, smoking and drinking habits, sources of drinking water, number of children and history of gastric cancer had no significant association with H. pylori infection (p ≥ 0.05). Conclusion: The results of the questionnaire revealed that most socio-demographic characteristics of the respondents had no significant association with H. pylori. Overcrowding, having siblings/parents with history of ulcer/gastritis as well as prior antibiotic usage had a significant association.

Anti-Helicobacter pylori Potential of Three Edible Plants Known as Quelites in Mexico

"Quelites" are edible plants that are part of the traditional agro-ecosystems in Mexico. These plants, despite their already known nutritional properties, are now considered neglected and underutilized species. With the objective of promoting their reinsertion in the markets and mainly, in daily diets, efforts have been made to study them from multidisciplinary approaches to demonstrate their beneficial properties. To generate evidence of an added health-promoting value that would encourage quelites consumption, in the present work, the anti-Helicobacter pylori activity of three representative quelite species, Anoda cristata (Alache), Cnidoscolus aconitifolius (Chaya), and Crotalaria pumila (Chepil), was tested. H. pylori is considered the etiological agent of gastritis, ulcer, and gastric cancer, and represents a public health problem in Mexico and worldwide. Aqueous (AQ) and dichloromethane-methanol (DM) extracts were obtained from the three species of quelites to investigate their effect on H. pylori growth and on two of its colonization factors (adherence and urease activity). DM extracts from Chaya, Chepil, and Alache exert the best inhibitory effect on bacterial growth, with minimum inhibitory concentrations of 62.5, 125, and 250 μg/mL, respectively. AQ and DM extracts inhibit bacterial adhesion by 30% to 50%. None of them has an effect on urease activity. The two flavonoids present in A. cristata, acacetin and diosmetin, inhibit H. pylori growth by ∼90% with 3.9 μg/mL. These results provide new information about the anti-H. pylori potential of three edible quelites, and give an added value, since their routine consumption may impact on the prevention and/or control of H. pylori-associated diseases.

The fourth Mexican consensus on Helicobacter pylori

Important advances have been made since the last Mexican consensus on the diagnosis and treatment of Helicobacter pylori (H. pylori) infection was published in 2007. Therefore, the Asociación Mexicana de Gastroenterología summoned 20 experts to produce "The Fourth Mexican Consensus on Helicobacter pylori". From February to June 2017, 4 working groups were organized, a literature review was performed, and 3 voting rounds were carried out, resulting in the formulation of 32 statements for discussion and consensus. From the ensuing recommendations, it was striking that Mexico is a country with an intermediate-to-low risk for gastric cancer, despite having a high prevalence of H. pylori infection. It was also corroborated that peptic ulcer disease, premalignant lesions, and histories of gastric cancer and mucosa-associated lymphoid tissue lymphoma should be considered clear indications for eradication. The relation of H. pylori to dyspeptic symptoms continues to be controversial. Eradication triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor should no longer be considered first-line treatment, with the following 2 options proposed to take its place: quadruple therapy with bismuth (proton pump inhibitor, bismuth subcitrate, tetracycline, and metronidazole) and quadruple therapy without bismuth (proton pump inhibitor, amoxicillin, clarithromycin, and metronidazole). The need for antimicrobial sensitivity testing when 2 eradication treatments have failed was also established. Finally, the promotion of educational campaigns on the diagnosis and treatment of H. pylori for both primary care physicians and the general population were proposed.

Diagnosis of Helicobacter pylori Using Invasive and Noninvasive Approaches

Helicobacter pylori (H. pylori) as gram-negative and spiral microorganism is responsible for colonization in the gastric microniche for more than 50% of world population. Recent studies have shown a critical role of H. pylori in the development of peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. Over the past decade, there has been a sharp interest to use noninvasive tests in diagnosis of the H. pylori infection. During the years after discovery by Marshall and Warren, it has been frequently declared that the rapid urease test (RUT) is one of the cheapest and rapid diagnostic approaches used in detecting the infection. Although the specificity and sensitivity are durable for this test, clinical experiences had shown that the ideal results are only achieved only if we take biopsies from both corpus and antrum at the same time. Given the diagnosis of the H. pylori in clinical samples, gastroenterologists are facing a long list of various molecular and nonmolecular tests. We need more in-depth researches and investigations to correctly generalize rapid and accurate molecular tests determining both bacterial identity and antibiotic resistance profile.

Force of infection of Helicobacter pylori in Mexico: evidence from a national survey using a hierarchical Bayesian model

Helicobacter pylori (H. pylori) is present in the stomach of half of the world's population. The force of infection describes the rate at which susceptibles acquire infection. In this article, we estimated the age-specific force of infection of H. pylori in Mexico. Data came from a national H. pylori seroepidemiology survey collected in Mexico in 1987-88. We modelled the number of individuals with H. pylori at a given age as a binomial random variable. We assumed that the cumulative risk of infection by a given age follows a modified exponential catalytic model, allowing some fraction of the population to remain uninfected. The cumulative risk of infection was modelled for each state in Mexico and were shrunk towards the overall national cumulative risk curve using Bayesian hierarchical models. The proportion of the population that can be infected (i.e. susceptible population) is 85.9% (95% credible interval (CR) 84.3%-87.5%). The constant rate of infection per year of age among the susceptible population is 0.092 (95% CR 0.084-0.100). The estimated force of infection was highest at birth 0.079 (95% CR 0.071-0.087) decreasing to zero as age increases. This Bayesian hierarchical model allows stable estimation of state-specific force of infection by pooling information between the states, resulting in more realistic estimates.

Influence of Helicobacter pylori virulence factors CagA and VacA on pathogenesis of gastrointestinal disorders

Helicobacter Pylori (H. pylori) is a gram-negative bacteria infecting numerous people all over the world. It has been established that H. pylori play an important role in pathogenesis of gastritis, peptic ulcer and gastric cancer. Pathogenic features of this bacterium are mainly attributes to the existence of pathogenic islands (PAI) genes. The most known genes in these islands are cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene (VacA). Most studies demonstrated various frequency of CagA and VacA in patient with peptic ulcer or gastritis in different countries. This variation in CagA and VacA frequency may be due to the capability of this bacterium to be genetically versatile and can alter the expression of these genes with geographic diversity. Although H. pylori infection is not usually associated with any clinical symptoms, but sometimes leads to inflammation in gastrointestinal system and resulted in peptic ulcer and gastric cancer. In this regard, this review will illustrate the importance of Helicobacter pylori in pathogenesis of gastrointestinal disorders with focusing on CagA and VacA virulence factors.

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children

The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n = 100) were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P < 0.001). In 34.6% (9/26) of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6) of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26), 83.3% (5/6), and 16.7% (1/6) of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P < 0.001). The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children.

Eosinophilic esophagitis. The North against the South? A bio-economic-social mechanistic approach and clinical implications

Eosinophilic esophagitis is a chronic antigen-mediated disease characterized by esophageal symptoms, esophageal eosinophilia, and the absence of response to proton pump inhibitors. It is the most frequent cause of dysphagia and food impaction in adults. Its incidence and prevalence is very high in the developed countries (USA, Europe, Australia), where its connotation is that of an emerging epidemic. While studies have been published with large case series in the developed countries, those published in Latin America are small or consist of isolated case reports. The differences in the prevalence of the disease between the developed and developing regions are unknown. Genetic or racial causes have been cited. Nevertheless, the epidemic nature of the disease suggests that environmental causes are the most powerful. Based on the published hypotheses, as well as on epidemiologic studies, the present review discusses some of the possible causes of the disparity in the prevalence of eosinophilic esophagitis between the two types of countries. The 'hygiene hypothesis' is reviewed, together with the possible relation of Helicobacter pylori, intestinal parasites, and modifications of the esophageal microbiota in patients with eosinophilic esophagitis. In reference to studies conducted in the United States, the clinical behavior and progression of eosinophilic esophagitis in Hispanics is reviewed and a possible predominant phenotype in Mexican and other Latin American patients is discussed. Finally, based on the above, an algorithm for studying the disease in the Latin American countries is proposed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Approach, attitudes, and knowledge of general practitioners in relation to Helicobacter pylori is inadequate. There is much room for improvement!

BACKGROUND

Helicobacter pylori (Hp) infection is one of the most common infections in humans. Due to its worldwide prevalence, a series of guidelines and recommendations has been developed for the appropriate screening, diagnosis, and management of patients with Hp infection.

AIM

To evaluate the approach, attitudes, and knowledge of a group of Mexican general practitioners in relation to Hp.

MATERIALS AND METHODS

A cross-sectional study was conducted that evaluated the knowledge of Hp diagnosis and treatment through the application of a questionnaire.

RESULTS

From the total of 430 questionnaires delivered, information was obtained from 411 (95% response rate). The most frequent indications for eradication treatment were peptic ulcer (48.4%), gastroesophageal reflux disease (41.8%), and dyspepsia (39.2%). Thirty-one percent of the physicians surveyed used more than one test to look for Hp, and serology was the most commonly employed method. The most widely used antibiotic regimen was clarithromycin plus amoxicillin (63.8%), followed by metronidazole plus tetracycline (16%). Ninety-two percent of the physicians confirmed eradication through endoscopy for the histologic analysis and only 23% utilized the breath test.

CONCLUSIONS

Our results show the lack of knowledge about the established diagnostic and treatment recommendations for Hp infection. The implementation of workshops, courses, and conferences, or the formulation of practical guidelines should be directed at primary care physicians to strengthen the practice of medicine based on scientific evidence.

Molecular docking, molecular dynamics simulation, biological evaluation and 2D QSAR analysis of flavonoids from Syzygium alternifolium as potent anti-Helicobacter pylori agents

The present study was carried out with the specific aim to evaluate anti-Helicobacter pylori(Hp) and urease inhibitory activities of three flavonoids from Syzygium alternifolium through thein vitroand bio-computational approaches.

Sero-prevalence and associated factors of Helicobacter pylori infection among adult patients with dyspepsia attending the gastroenterology unit in a tertiary hospital in Mwanza, Tanzania

BACKGROUND

Prevalence of H.pylori infection varies greatly between populations in different countries. This study was conducted to determine the magnitude of H.pylori among adult patients with dyspepsia attending the gastroenterology unit at Bugando medical centre.

METHODS

A cross sectional study involving 202 dyspeptic patients was conducted between June and July 2014. A Standardized data collection tool was used to collect socio-demographic characteristics. H.pylori antibodies were detected using rapid immunochromatographic tests according to manufacturer's instructions.

RESULTS

The median age of study population was 42 (IQR: 33-54). Females 105 (51.9%) formed majority of the population studied. Of 202 participants; 119 (58.9%) were from rural areas. Seroprevalence of H.pylori infection was found to be 79/202 (39.1%, 95% CI: 32.3-45.7). As the age increased the risk of having H.pylori infection also increased (OR: 1.02 95% CI: 1-1.04, P=0.02). On multivariate logistic regression analysis untreated drinking water was found to predict H.pylori seropositivity (OR: 2.33, CI: 1.09-4.96, p=0.028).

CONCLUSION

The seroprevalence of H.pylori among dyspeptic patients is high in this setting. Therefore the community in Mwanza should be educated on the use of safe drinking water in order to minimize H. pylori infections.

Helicobacter pylori detection and clinical symptomatology of gastroesophageal reflux disease in pediatric patients with otitis media with effusion

OBJECTIVES

The study aimed to demonstrate Helicobacter pylori presence in otitis media with effusion (OME) and its association with symptomatology of gastroesophageal reflux disease (GERD).

METHODS

In a cohort study, 69 effusions were collected during tympanostomy tube insertion for H. pylori detection using PCR and ELISA. Validated questionnaires were performed according to age for clinical diagnosis of GERD; chi-square ×2 statistical analysis was made.

RESULTS

Eight of the 69 ear effusions (5.7%) were positive for H. pylori detection using ELISA. Two patients (2.9%) had positive results for H. pylori detection using ELISA and PCR. These eight patients had positive results too in GERD questionnaires. None of the patients with negative/suspect questionnaires had positive results for H. pylori. We found statistical association between the results of ELISA, PCR and questionnaires (×2, p = 0.001).

CONCLUSIONS

The H. pylori presence in effusions varies widely, in our population the frequency was lower than other reports. We found strong association between H. pylori in effusions and positive GERD questionnaires. The bacterium role in OME chronicity is not clear, but this study supports the GERD participation in OME pathogenesis.

A 5-year trend of Helicobacter pylori seroprevalence among dyspeptic patients at Bahir Dar Felege Hiwot Referral Hospital, Northwest Ethiopia

Background

Helicobacter pylori infection is a major public health problem affecting half of the world's population. The prevalence of H. pylori varies in different societies and geographical locations. Thus, timely information on H. pylori epidemiology is critical to combat this infection. This study aimed to determine the seroprevalence and trend of H. pylori infection over a period of 5 years among dyspeptic patients at Bahir Dar Felege Hiwot Referral Hospital, Northwest Ethiopia.

Methods

A retrospective analysis of consecutive dyspeptic patients' records covering the period between January 2009 and December 2013 was conducted. The hospital laboratory generated the data by a serological method of detecting the antibodies for H. pylori from serum by a one-step rapid test device. Chi-square analysis was used to identify significant predictors. A P-value of <0.05 was considered as statistically significant.

Results

Among all the study subjects, 2,733 (41.6%) were found to be seropositive. The seroprevalence was significantly higher in males (43.2%) than in females (39.9%) (χ²=9; P=0.002). In terms of age groups of the patients, high rates of H. pylori were found among the participants older than 60 years (57%) (χ²=36.6; P≤0.00001). The trend analysis of H. pylori prevalence revealed a fluctuating prevalence; it was 44.5% in the year 2009 and decreased to 34% and 40% in the years 2010 and 2011, respectively. However, there was an increment to 52.5% in the year 2012, and then it decreased to 30.2% in the year 2013.

Conclusion

This study showed high seroprevalence of H. pylori among the dyspeptic patients in Bahir Dar Felege Hiwot Referral Hospital. The trend of the seroprevalence varied from year to year in the 5 consecutive years. Considering this, designing appropriate prevention and control strategies is mandatory.

Helicobacter pylori colonization in Nepal; assessment of prevalence and potential risk factors in a hospital-based patient cohort

Background

Helicobacter pylori, a gram-negative bacterium, can cause gastritis, peptic and duodenal ulcers. It is considered an important public health problem for both developed and developing world. This bacterium is classified as the class 1 carcinogen because it can cause cancer.

Methods

A hospital based study was conducted at Chitwan Medical College Teaching Hospital (CMCTH) from May to October 2014. Stool samples were collected from the suspected patients and were subjected to detection of the H. pylori stool antigen (HpSAg) following the procedures recommended by the manufacturer. A standard questionnaire on the potential risk factors was also designed and completed.

Result

HpSAg was detected in 16 % of suspected patients. The children up to 10 years of age were found to be highly infected (36 %). The patients living in urban area were found more susceptible to develop H. pylori infection (P < 0.05). Tea drinking and repeated eating habit (more than twice a day) were listed as the important factors that can limit the H. pylori infections significantly (P < 0.05).

Conclusion

In this hospital based study, a significant rate of prevalence was evaluated. However, we recommend a community based extensive study to reveal the real scenario of H. pylori infection in Nepalese populations.

Intergenerational reduction in Helicobacter pylori prevalence is similar between different ethnic groups living in a Western city

OBJECTIVE

Helicobacter pylori colonisation rates in childhood have declined in Western populations, but it is unknown whether this trend is similar in children of non-Western ethnic backgrounds, born in a Western country. We aimed to identify H. pylori status in children, and determine mother-to-child transmission and risk factors for colonisation.

DESIGN

Antibodies against H. pylori and cytotoxin-associated gene A (CagA) were measured in children participating in a population-based prospective cohort study in Rotterdam, the Netherlands. Information on demographics and characteristics was collected using questionnaires.

RESULTS

We analysed the serum of 4467 children (mean age 6.2 years±0.4 SD) and compared the results with the H. pylori status of their mothers (available for 3185 children). Overall, 438 (10%) children were H. pylori-positive, of whom 142 (32%) were CagA-positive. Independent risk factors for colonisation were: maternal H. pylori positivity (OR 2.12; 95% CI 1.62 to 2.77), non-Dutch ethnicity (OR 2.05; 95% CI 1.54 to 2.73), female gender (OR 1.47; 95% CI 1.20 to 1.80) and lower maternal education level (OR 1.38; 95% CI 1.06 to 1.79). Comparing mothers and children, we found an intergenerational decrease of 76% and 77% for Hp(+)CagA(-) and Hp(+)CagA(+)-strains, respectively, consistent across all nine ethnic groups studied. Male gender, higher maternal educational level and no older siblings, were independently associated with absence of H. pylori.

CONCLUSIONS

Although the highest H. pylori and CagA prevalence was found in children of non-Dutch ethnicities, the decreased colonisation rates were uniform across all ethnic groups, implying the importance of environmental factors in H. pylori transmission in modern cities, independent of ethnicity.

The Serum Immunoglobulin G Glycosylation Signature of Gastric Cancer

Biomarkers may facilitate detection of gastric cancer at an earlier stage and reduce mortality. Here we sought to determine if the glycosylation profile of serum immunoglobulin G (IgG) could distinguish patients with non-atrophic gastritis (NAG), duodenal ulcer (DU) and gastric cancer (GC). Serum IgG was released and analyzed using nano-LC-TOF mass spectrometry. Statistically significant false discovery rate (FDR)-adjusted p-values were observed for 18 glycans, eight that differed significantly between NAG and GC, three that distinguished NAG from DU, and eight that differed between DU and GC. The IgG glycosylation signature may be useful as a predictive marker for gastric cancer.

Prevalence of Helicobacter pylori infection worldwide: a systematic review of studies with national coverage

The systematic assessment of large population-based surveys addressing the prevalence of Helicobacter pylori infection may provide robust evidence for understanding the trends in the exposure to this major risk factor across settings with distinct patterns of gastric cancer variation. Our aim was to describe the prevalence of H. pylori infection in different countries and periods, through systematic review of the literature. We searched PubMed from inception up to September 2013 to identify original studies reporting on the prevalence of H. pylori, and only those evaluating samples with national coverage were included. We identified 37 eligible studies including data for 22 countries. The prevalences were higher in Central/South America and Asia, and at least two-fold higher in countries with high gastric cancer incidence. In most countries presenting data for different time periods, the prevalences were usually lower in the most recent surveys. However, there was little variation in settings where prevalences were already low. Among countries with high prevalence of H. pylori infection there is an ample scope for reducing its burden in the next decades, whereas further declines in settings with already low prevalences will require more intensive efforts.

Stomach microbiota composition varies between patients with non-atrophic gastritis and patients with intestinal type of gastric cancer

We aimed to characterize microbiota of the gastric mucosa as it progress to intestinal type of cancer. Study included five patients each of non-atrophic gastritis (NAG), intestinal metaplasia (IM) and intestinal-type gastric cancer (GC). Gastric tissue was obtained and DNA extracted for microbiota analyses using the microarray G3 PhyloChip. Bacterial diversity ranged from 8 to 57, and steadily decreased from NAG to IM to GC (p = 0.004). A significant microbiota difference was observed between NAG and GC based on Unifrac-presence/absence and weighted-Unifrac-abundance metrics of 283 taxa (p < 0.05). HC-AN analyses based on presence/absence of 238 taxa revealed that GC and NAG grouped apart, whereas IM overlapped with both. An ordinated analyses based on weighted-Unifrac distance given abundance of 44 taxa showing significance across categories revealed significant microbiota separation between NAG and GC. This study is the first to show a gradual shift in gastric microbiota profile from NAG to IM to GC.

Present and past Helicobacter pylori infection in Mexican school children

BACKGROUND

In developing countries, more than 50% of children have serological evidence of Helicobacter pylori infection. However, serological tests for H. pylori did not differentiate between active and past infection. The objectives of this study were to estimate the frequency of active and past H. pylori infection utilizing functional urea breath test (UBT) and serological tests and evaluate factors associated with the infection.

METHODS

A total of 675 school children, 6-13 years of age, participated. UBT was performed to detect active H. pylori infection. Blood samples were obtained to determine iron status and Immunoglobulin G (IgG) responses to the H. pylori whole-cell and to Cag A antigens by antigen-specific enzyme-linked immunosorbent assays. Weight, height, and sociodemographic characteristics were recorded.

RESULTS

A total of 37.9% (95% Confidence Intervals (CI): 34.2-41.6) of school children had active or past H. pylori infection; of them, 73.8% (CI95% 68.4-79.2) were carrying CagA-positive strain, 26.5% (CI95% 23.2-29.8) had active infection, and 11.4% (95%CI: 9.0-13.8) had evidence of past H. pylori infection. School children with iron deficiency and low height for age had higher risk of H. pylori infection: [OR to active or past infection was 2.30 (CI 95% 1.01-5.23) and to active infection it was 2.64 (CI 95% 1.09-6.44)] compared to school children with normal iron status and height for age or with normal iron status but low height for age or with iron deficiency and normal height for age.

CONCLUSIONS

The estimated prevalence of infection depends of the test utilized. Frequency of H. pylori infection and carrying CagA-positive strains was high in this population. Malnutrition was associated with active H. pylori infection.