Long-term follow-up of the incidence of Helicobacter pylori

Pathogenicity and virulence of Helicobacter pylori: A paradigm of chronic infection

Infection with Helicobacter pylori is one of the most common infections of mankind. Infection typically occurs in childhood and persists for the lifetime of the host unless eradicated with antimicrobials. The organism colonizes the stomach and causes gastritis. Most infected individuals are asymptomatic, but infection also causes gastric and duodenal ulceration, and gastric cancer. H. pylori possesses an arsenal of virulence factors, including a potent urease enzyme for protection from acid, flagella that mediate motility, an abundance of outer membrane proteins that can mediate attachment, several immunomodulatory proteins, and an ability to adapt to specific conditions in individual human stomachs. The presence of a type 4 secretion system that injects effector molecules into gastric cells and subverts host cell signalling is associated with virulence. In this review we discuss the interplay of H. pylori colonization and virulence factors with host and environmental factors to determine disease outcome in infected individuals.

Protocol for a randomised 'screen-and-treat' Helicobacter pylori eradication trial in 14-18-years-old adolescents residing in three regions of Chile: effectiveness and microbiological host implications

INTRODUCTION

Gastric cancer is a major global health concern, being the final stage of a long-term process, primarily associated with Helicobacter pylori (H. pylori) infection. Early childhood acquisition of H. pylori with low spontaneous eradication rates underscores the need for preventive measures. Our previous pilot treatment study revealed high eradication rates, favourable tolerance profile and a decline in serum biomarkers indicative of gastric damage in asymptomatic school-aged children. The purpose of this study is to determine the potential benefit of a 'screen-and-treat' strategy targeting persistently infected, asymptomatic adolescents. Specific aims are to assess eradication efficacy, its clinical and molecular outcomes and potential clinical and microbiological side effects.

METHODS AND ANALYSIS

The screening phase will involve testing 500-1000 asymptomatic adolescents aged 14-18 from three cities in Chile using the urea breath test (UBT) to identify 210 participants with persistent infection. They will proceed to a randomised, non-blinded, controlled trial, receiving either a sequential eradication scheme for H. pylori or no treatment. Follow-up will span up to 24 months post-treatment, involving UBT, gastroenterological assessments and blood and stool sample collections. Concurrently, a subset of 60 uninfected adolescents will undergo matched follow-up. Enzyme-linked immunosorbent assay (ELISA) commercial kits will evaluate gastric damage biomarkers in serum (pepsinogen I and II, gastrin-17, VCAM-1, CXCL13). Stool samples will be employed for Escherichia coli and Enterococcus spp-culture, assessing AMR via the disk diffusion method. H. pylori clarithromycin resistance will be determined by molecular method from stool samples. The gut microbiome will be characterised by amplifying and sequencing the 16S rRNA gene from stool samples, followed by bioinformatics analysis.

ETHICS AND DISSEMINATION

Approved by the Human Research Ethics Committee at the Faculty of Medicine, University of Chile (073-2022). Findings will be disseminated in peer-reviewed journals and scientific meetings to guide future practices.

TRIAL REGISTRATION NUMBER

NCT05926804.

Prevalence of Helicobacter pylori in routine adult tonsillectomies

Helicobacter pylori, a curved bacterial rod and causative agent of peptic ulcer and gastric adenocarcinoma, is found as an infectious agent in the stomach of over half of the global population. H. pylori has been identified in oral biofilms and its presence in adenotonsillar tissues has been suggested, with variations in testing methodology both proving and disproving its presence. The current study employed 119 formalin-fixed paraffin-embedded tonsillar tissues from an adult population (n=86) in a major metropolitan city with immunohistochemistry procedures using a monoclonal antibody to determine the incidence of H. pylori in the tonsils. H. pylori was identified in 72.1% of the patients and was associated with Actinomyces spp. in 92.0% of those cases. The high incidence of H. pylori in patients undergoing tonsillectomy suggests that H. pylori may be a contributing factor for tonsillitis and tonsillar hypertrophy. Furthermore, the reservoir for H. pylori in the tonsils may explain why some persons remain refractory to antibiotic treatment for gastric H. pylori.

Factors Associated With Decision to Treat or Not to Treat Helicobacter pylori Infection in Children: Data From the EuroPedHp Registry

BACKGROUND

European and North-American guidelines on management of H. pylori infection in children provide the option not to treat even if the infection is endoscopically confirmed. We used data from the EuroPedHp Registry to identify factors associated with therapy decisions.

METHODS

We included treatment-naïve patients reported between 2017 and 2020 from 30 centers in 17 European countries. Multivariable logistic regression identified factors including comorbidities within and outside the gastrointestinal (GI) tract influencing the decision for or against therapy.

RESULTS

Of 1165 patients (52% females, median age 12.8), 28% (321/1165) reported any alarm symptom, 26% (307/1165) comorbidities, and 16% (192/1165) did not receive eradication treatment. Therapy was initiated less often in children having any GI comorbidity (57%, n = 181), particularly in those with eosinophilic esophagitis (60%, n = 35), inflammatory bowel disease (54%, n = 28), and celiac disease (43%, n = 58), compared to those with non-GI (86%, n = 126) or no comorbidity (89%, n = 858), despite similar frequencies of alarm and non-alarm symptoms, ulcers, erosions, and nodular gastritis. Patients with GI and without comorbidities remained more likely untreated in high versus low H. pylori prevalence countries (p < 0.0001). In children without comorbidities, factors favoring therapy included older age, being overweight, having symptoms, erosions, antral nodularity, and available antibiotic susceptibility results.

CONCLUSION

In this cohort, H. pylori-infected children with GI comorbidities compared to no comorbidity showed 75% reduced chance of receiving eradication therapy. We found no evidence supporting different management strategies in infected patients with GI comorbidities compared to all pediatric patients with endoscopically proven H. pylori infection.

A comparison of staining methods for Helicobacter pylori in laparoscopic vertical sleeve gastrectomy resections

BACKGROUND

Helicobacter pylori is an important public health concern due to its status as a carcinogenic bacterium. Well adapted to the acidic environment of the human stomach, the variety of strains and virulence factors of the organism when interacting with the host immune system creates an individualistic response. Although estimates suggest that approximately half of the global population is infected with H pylori, the majority of infected persons remain asymptomatic while harboring an increased risk of intestinal metaplasia and gastric cancers. Therefore, appropriate diagnostic testing protocols are imperative.

METHODS

This study compared labeling methodologies, including Wright stain, alcian yellow toluidine blue (AYTB), and immunohistochemistry (IHC) on formalin-fixed paraffin-embedded stomach resections from sleeve gastrectomy patients, to detect H pylori infection.

RESULTS

Although all 3 labeling methods evidenced similar specificity in H pylori detection, the IHC method was significantly more sensitive. However, the IHC cost per test was approximately 5-fold higher than that of the Wright or AYTB stains, and the technical time required per test was at least 6-fold that of Wright or AYTB.

CONCLUSION

Despite the higher cost per test, IHC is the most sensitive and preferred method for determination of H pylori infection.

Upper gastrointestinal bleeding: Diagnosis of Helicobacter pylori infection-Descriptive study

Background and Aim

The presence of blood in the stomach has been thought to affect the performance of diagnostic tests used in detecting Helicobacter pylori (H. pylori) in the stomach. This study evaluates the effect of upper gastrointestinal bleeding on the efficacy of a rapid urease test (RUT) and compares the results with the pathologic method.

Methods

In this descriptive study, 100 patients presented with upper gastrointestinal bleeding, confirmed from endoscopy, referred to Shahid Rahimi Hospital in Khorramabad were enrolled. Antral biopsy was performed in all the patients and the samples were extracted for histopathology and RUT. A questionnaire was used to collect rapid urease test outcomes and associated parameters (antibiotic, bismuth, and proton pump inhibitors), histology and demographic data. Histopathology was used as the gold standard for diagnosis of H. pylori.

Results

Of the 52 patients who were reported positive for H. pylori in pathology, 36 had RUT-positive H. pylori, sensitivity 69.2%, and of 48 patients whose pathology was negative, 25 had negative RUT, specificity 52.1%. Of 59 RUT, 36 had positive pathology, positive predictive value was 61% and from 41 with negative RUT, 25 had negative pathology, negative predictive value was 61%. The prevalence of H. pylori infection was significantly associated with the age of 50 years and above, p = 0.042, and previous history of bleeding, p = 0.019.

Conclusion

Gastrointestinal bleeding can reduce the sensitivity of RUT. The negative results of these tests in acute upper gastrointestinal bleeding should therefore be interpreted carefully.

Community prevalence of Helicobacter pylori and dyspepsia and efficacy of triple therapy in a rural district of eastern Uganda

Background

Helicobacter pylori (H. pylori) infection and chronic dyspepsia represent significant medical burdens in the developing world. An accurate assessment of the prevalence of chronic dyspepsia, as well as of the effectiveness of population-based screening and eradication of H. pylori are warranted.

Objectives

We determined the prevalence of H. pylori and chronic dyspepsia within the general adult population in a region of eastern Uganda. Independent predictors of H. pylori infection were assessed. Finally, we evaluated the efficacy of standard triple therapy on H. pylori eradication.

Methods

Of 400 randomly selected adult residents in eastern Uganda, 376 were administered a validated, chronic dyspepsia questionnaire and provided a stool sample for H. pylori testing. H. pylori-positive participants were given standard triple therapy and monitored for medication adherence. The efficacy of triple therapy on H. pylori eradication was determined by fecal antigen testing after treatment. Log-linear and logistic regression analyses identified predictors of H. pylori positivity and eradication failure.

Results

H. pylori prevalence within the study population was 48%. The prevalence of chronic dyspepsia was 87%. The presence or severity of dyspepsia did not predict H. pylori infection. However, a higher level of education was an independent predictor of H. pylori infection. Standard triple therapy resulted in ∼90% eradication. Missing at least four doses of any of the triple therapy medications over the 14-day course predicted eradication failure.

Conclusions

In our study population, chronic dyspepsia did not predict H. pylori infection, though clinical suspicion for this prevalent pathogen should nonetheless remain high. Population-based screening and adherence to triple therapy are effective at eradicating H. pylori within this region.

Contribution of Helicobacter pylori to the Inflammatory Complications of Common Variable Immunodeficiency

Common Variable Immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency, is frequently associated with severe inflammatory complications that determine its morbidity and mortality. We hypothesize that Helicobacter pylori (HP), a very common worldwide infection, may contribute to the clinical and immune phenotype of CVID. We stratified 41 CVID patients into HP+ (n=26) and HPneg (n=15) groups, according to previous urease breath test and/or gastric biopsies, and compared their clinical manifestations and immune profile evaluated by flow cytometry. No genetic variants with known potential impact in HP infection were found upon WES/WGS. Gastric complications were significantly more frequent in HP+ patients. Importantly, the six CVID patients with gastric cancer were infected with HP. In contrast, a significantly higher frequency of cytopenias was observed in the HPneg. Moreover, HP+ did not feature higher prevalence of organ auto-immunity, as well as of lung, liver or intestinal inflammatory manifestations. We observed the same B-cell profiles in HP+ and HPneg groups, accompanied by marked CD4 and CD8 T-cell activation, increased IFNγ production, and contraction of naïve compartments. Notably, HP+ patients featured low CD25 despite preserved Foxp3 levels in CD4 T cells. Overall, HP impact in CVID inflammatory complications was mainly restricted to the gastric mucosa, contributing to increased incidence of early onset gastric cancer. Thus, early HP screening and eradication should be performed in all CVID patients irrespective of symptoms.

The global prevalence of and factors associated with Helicobacter pylori infection in children: a systematic review and meta-analysis

BACKGROUND

Synthesised data on the prevalence of, and factors associated with, paediatric Helicobacter pylori infection at the global level remain scarce. We aimed to estimate the global prevalence of H pylori infection and its associated factors in children and adolescents.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, MEDLINE, and Scopus for observational population-based studies published between database inception and Oct 25, 2021, without language or geographical restrictions. We included studies that reported the prevalence of H pylori infection in children aged 18 years or younger. Records were screened and data were extracted using a standardised extraction form. We estimated the worldwide prevalence of H pylori infection in children (our main outcome) using multilevel mixed-effects meta-regression and then stratified prevalence by diagnostic method (serology vs urea breath tests or stool antigen tests). We analysed the significance of associated factors using a random-effects meta-analysis. This study is registered in PROSPERO, CRD42020209717.

FINDINGS

We identified 3181 records, of which 198 articles with 632 data points from 152 650 children were included. The overall global prevalence of H pylori infection in children was 32·3% (95% CI 27·3-37·8), which varied by diagnostic test (28·6% [23·0-35·0] for serology vs 35·9% [29·2-43·2] for urea breath tests or stool antigen tests). Regardless of diagnostic test, the prevalence of H pylori infection was significantly higher in low-income and middle-income countries than in high-income countries (43·2% [36·5-50·2] vs 21·7% [16·9-27·4]; p<0·0001) and in older children than in younger children (41·6% [35·6-47·8] in 13-18-year-olds vs 33·9% [28·6-39·7] in 7-12-year-olds vs 26·0% [21·4-31·0] in 0-6-year-olds; p<0·0001). Paediatric H pylori infection was significantly associated with lower economic status (odds ratio [OR] 1·63 [95% CI 1·46-1·82]), more siblings or children (1·84 [1·44-2·36]), room sharing (1·89 [1·49-2·40]), no access to a sewage system (1·60 [1·22-2·10]), having a mother infected with H pylori (3·31 [2·21-4·98]), having a sibling or siblings infected with H pylori (3·33 [1·53-7·26]), drinking unboiled or non-treated water (1·52 [1·32-1·76]), and older age (OR per year 1·27 [1·15-1·40]).

INTERPRETATION

H pylori infection is still highly prevalent in children and adolescents globally. Our findings can help to guide further research and the development and implementation of preventive and therapeutic measures to reduce H pylori infection in children.

FUNDING

None.

Children and adolescents’ health on focus: Gastrointestinal injuries associated with Helicobacter pylori

Objective: To describe the prevalence of Helicobacter pylori (HP) in children and adolescents, and to assess its association with lesions in the esophagus, stomach, and duodenum according to the patient’s life cycle. Methodsː A cross-sectional analytical study with children and adolescents referred to a gastroenterology service and underwent esophagogastroduodenoscopy at a hospital in Vitória, Espírito Santo, Brazil, from 2001 to 2013. Variables analyzed were the following: sex, age, macro and microscopic alterations and severity of infestation. The Chi-square and Fisher's exact tests and adjusted residue analysis were used (α = 5%). Resultsː the prevalence of infection was 24.4%. Esophagitis (29.4%) and gastritis (34.1%) were associated with HP. The life cycle was associated with esophagitis and duodenitis. Infection was associated with life cycle: infants (0.8%), preschool children (10.5%), school-aged children (16.5%), and adolescents (72.2%). The residues showed a strong association between HP and gastritis, and no association between the school-aged and esophagitis. Adolescents were the major contributors to the association between life cycle and infection, and life cycle and lesion. Conclusionsː Infection with HP was associated with esophagitis and gastritis and was higher among adolescents, who had a marked tendency to develop gastritis and a milder tendency to develop esophagitis. The tendency of developing infection and gastritis was not present in the other life cycles. Public policies focusing on promotion and protecting health, especially in vulnerable population groups, are needed.

Helicobacter pylori Infection in Pediatric Patients Living in Europe: Results of the EuroPedHP Registry 2013 to 2016

OBJECTIVES

The aim of the study was to assess clinical presentation, endoscopic findings, antibiotic susceptibility and treatment success of Helicobacter pylori (H. pylori) infected pediatric patients.

METHODS

Between 2013 and 2016, 23 pediatric hospitals from 17 countries prospectively submitted data on consecutive H. pylori-infected (culture positive) patients to the EuroPedHP-Registry.

RESULTS

Of 1333 patients recruited (55.1% girls, median age 12.6 years), 1168 (87.6%) were therapy naïve (group A) and 165 (12.4%) had failed treatment (group B). Patients resided in North/Western (29.6%), Southern (34.1%) and Eastern Europe (23.0%), or Israel/Turkey (13.4%). Main indications for endoscopy were abdominal pain or dyspepsia (81.2%, 1078/1328). Antral nodularity was reported in 77.8% (1031/1326) of patients, gastric or duodenal ulcers and erosions in 5.1% and 12.8%, respectively. Primary resistance to clarithromycin (CLA) and metronidazole (MET) occurred in 25% and 21%, respectively, and increased after failed therapy. Bacterial strains were fully susceptible in 60.5% of group A, but in only 27.4% of group B. Primary CLA resistance was higher in Southern and Eastern Europe (adjusted odds ratio [ORadj] = 3.44, 95% confidence interval [CI] 2.22-5.32, P < 0.001 and 2.62, 95% CI: 1.63-4.22, P < 0.001, respectively) compared with Northern/Western Europe. Children born outside Europe showed higher primary MET resistance (ORadj = 3.81, 95% CI: 2.25-6.45, P < 0.001). Treatment success in group A reached only 79.8% (568/712) with 7 to 14 days triple therapy tailored to antibiotic susceptibility.

CONCLUSIONS

Peptic ulcers are rare in dyspeptic H. pylori-infected children. Primary resistance to CLA and MET is markedly dependent on geographical regions of birth and residence. The ongoing survey will show whether implementation of the updated ESPGHAN/NASPGHAN guidelines will improve the eradication success.

Review: Epidemiology of Helicobacter pylori infection

This review summarizes recent publications on the epidemiology of Helicobacter pylori. Two major systemic analyses, from Malaysia and Ethiopia, were published. The Brazilian Consensus Conference has stated that H pylori infection is an infectious disease with an indication for antimicrobial therapy. A continuous decrease in H pylori prevalence was reported from many regions worldwide, including Korea, China, Iran, and Austria. A cross-sectional H pylori prevalence study conducted in the United Arab Emirates found 41% prevalence in a group of healthy children and adults. Several studies from Asia addressed H pylori prevalence in adults undergoing regular checkup. The largest of such studies, performed in Korea, involved 24 471 subjects and reported 41.5% seroprevalence. A relatively smaller study from East China on 3252 subjects reported 27.5% prevalence. In contrast, a study from Spain reported 87.2% seroprevalence. A report on the association between smoking and H pylori seropositivity was published on behalf of the Stomach Cancer Pooling (StoP) Project-a consortium of epidemiological studies of gastric cancer. Also, other potential risk factors, including occupational risk factors, water supply, and food were analyzed. Gastroesophageal reflux and sexual partners has been associated with a higher risk for H pylori acquisition, and gut microbiota was suggested to play a role in intrafamilial transmission of H pylori. Finally, in a few studies (from Mexico and Japan), the catalytic model for predicting the potential risk of acquiring H pylori infection in the future was used. As anticipated, a further decline in H pylori-related disease was demonstrated by applying the modeling.

Helicobacter pylori Infection in Children and Adolescents

About one-third of all children worldwide is infected with H. pylori and its prevalence is low in developed and high in developing countries. H. pylori is mainly acquired during childhood and transmission of the bacterium commonly proceeds from person to person, especially among family members. The most frequent transmission route is from the mother to children. Various gastrointestinal and extra-gastrointestinal diseases are reported to be associated with H. pylori in children and adolescents, but the strongest recommendation for testing and treating is introduced only with children and adolescents having peptic ulcer disease. Iron deficiency anemia and chronic immune thrombocytopenic purpura are also considered for testing and treating, but the effectiveness is somewhat controversial. Invasive diagnosis is recommended, whereas none of the available diagnostic tests have 100% accuracy for reliable diagnosis, and therefore at least two or more tests should be performed. Urea breath test is the most reliable among the non-invasive tests. Because the number of antibiotics-resistant H. pylori strains is increasing, it is desirable to conduct a drug susceptibility test before treatment and to select the corresponding regime. H. pylori has been proven to be a major cause of gastric cancer and 'screen-and-treat' strategies are recommended in communities at high risk of gastric cancer. However, the application to children and adolescents is controversial. An effective vaccine is desirable, but not yet available. Screen-and-treat for adolescents has started in a few areas in Japan, where conditions are well established. New prevention strategies for gastric cancer are awaited worldwide.

The use of stool specimens reveals Helicobacter pylori strain diversity in a cohort of adolescents and their family members in a developed country

Helicobacter pylori infection occurs within families but the transmission route is unknown. The use of stool specimens to genotype strains facilitates inclusion of complete families in transmission studies. Therefore, we aimed to use DNA from stools to analyze strain diversity in H. pylori infected families. We genotyped H. pylori strains using specific biprobe qPCR analysis of glmM, recA and hspA. Concentration of H. pylori organisms before DNA isolation enhanced subsequent DNA amplification. We isolated H. pylori DNA from 50 individuals in 13 families. T_m data for at least 2 of the 3 genes and sequencing of the glmM amplicon were analyzed. Similar strains were commonly found in both mothers and children and in siblings. However, 20/50 (40%) individuals had multiple strains and several individuals harbored strains not found in other family members, suggesting that even in developed countries sources of infection outside of the immediate family may exist. Whether infection occurs multiple times or one transmission event with several strains occurs is not known but future studies should aim to analyze strains from children much closer to infection onset. The presence of multiple stains in infected persons has implications for antibiotic sensitivity testing and treatment strategies.