Reinfection rate and endoscopic changes after successful eradication of Helicobacter pylori

Development and validation of a convolutional neural network model for diagnosing Helicobacter pylori infections with endoscopic images: a multicenter study

BACKGROUND AND AIMS

Insufficient validation limits the generalizability of deep learning in diagnosing Helicobacter pylori infection with endoscopic images. The aim of this study was to develop a deep learning model for the diagnosis of H pylori infection using endoscopic images and validate the model with internal and external datasets.

METHODS

A convolutional neural network (CNN) model was developed based on a training dataset comprising 13,403 endoscopic images from 952 patients who underwent endoscopy at Seoul National University Hospital Gangnam Center. Internal validation was performed using a separate dataset comprised of images of 411 individuals of Korean descent and 131 of non-Korean descent. External validation was performed with the images of 160 patients in Gangnam Severance Hospital. Gradient-weighted class activation mapping was performed to visually explain the model.

RESULTS

In predicting H pylori ever-infected status, the sensitivity, specificity, and accuracy of internal validation for people of Korean descent were .96 (95% confidence interval [CI], .93-.98), .90 (95% CI, .85-.95), and .94 (95% CI, .91-.96), respectively. In the internal validation for people of non-Korean descent, the sensitivity, specificity, and accuracy in predicting H pylori ever-infected status were .92 (95% CI, .86-.98), .79 (95% CI, .67-.91), and .88 (95% CI, .82-.93), respectively. In the external validation cohort, sensitivity, specificity, and accuracy were .86 (95% CI, .80-.93), .88 (95% CI, .79-.96), and .87 (95% CI, .82-.92), respectively, when performing 2-group categorization. Gradient-weighted class activation mapping showed that the CNN model captured the characteristic findings of each group.

CONCLUSIONS

This CNN model for diagnosing H pylori infection showed good overall performance in internal and external validation datasets, particularly in categorizing patients into the never- versus ever-infected groups.

Helicobacter pylori results in lysis and death after exposure to water

BACKGROUND

Helicobacter pylori has a high infection rate, and it is possible that more than half of the world's population is infected. The route of transmission of H. pylori has not been completely elucidated yet. The coccoid form of H. pylori is generally considered to be in a VBNC (viable but nonculturable) state, and this form in the environment is thought to play an important role in infection and transmission, but its stability and survivability are still unknown.

MATERIALS AND METHODS

In order to promote its changing to coccoid form, the spiral form of H. pylori grown in a culture medium was exposed to sterile distilled water, and we investigated the bacterial cell number and the morphological changes by using fluorescence staining methods and electron microscopic observation. We also examined the dynamics of its growth ability by measuring the colony forming unit on an agar-plate medium.

RESULTS

After exposure to sterile distilled water, the H. pylori spiral form rapidly lost its growth ability at 37°C. One day after exposure, approximately 95% of the spiral form disappeared and the proportion of the coccoid form increased. The total number of bacteria also decreased to less than half and continued to decrease over time. Epi-microscopic and electron microscopic observations revealed that deformation of bacterial cells, collapse, and leaking out of cell contents were promoted in exposure to sterile distilled water.

CONCLUSION

Helicobacter pylori quickly begins to transform into the coccoid form after exposure to sterile distilled water, rapidly loses its growth ability, and then lyses and dies. Water-exposure is lethal for H. pylori and it is unlikely to survive in the VBNC state in water.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition)

OBJECTIVE

Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden.

METHODS

Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements.

RESULTS

Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases.

CONCLUSION

H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Helicobacter pylori recrudescence and its influencing factors

Helicobacter pylori (H pylori) is known as one of the most common infectious pathogens, with high infection and recurrence rates worldwide. The prevalence of H pylori is up to 90% in developing countries, while the annual recurrence rate is much higher than that in developed countries. Recurrence can occur either by recrudescence or reinfection. Compared with reinfection, the time window for recrudescence is generally shorter, followed by the recurrence of H pylori–associated diseases in the short‐term. Many factors are involved in the H pylori reinfection, such as the prevalence of H pylori infection, living conditions and economic development, health conditions and so forth. Previous studies focused less on H pylori recrudescence. Therefore, the influencing factors for H pylori recrudescence needed further exploration. This study reviewed the recrudescence of H pylori infection and its influencing factors.

Inference from the analysis of genetic structure of Helicobacter pylori strains isolates from two paediatric patients with recurrent infection

Background

Helicobacter pylori recurrence after successful eradication is an important problem. Children are particularly vulnerable to reinfection, by intrafamilial transmission which facilitates the acquisition or recombination of new genetic information by this bacterium. We investigated the evolutionary dynamics of 80 H. pylori strains isolated from two paediatric patients with recurrent infection (recrudescence and reinfection).

Results

We characterized the virulence genes vacA (s1, m1, s2, and m2), cagA, cagE, and babA2 and performed multilocus sequence typing (MLST) on 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, and yphC) to infer the evolutionary dynamics of the H. pylori strains through phylogenetic and genealogic inference analyses, genetic diversity analysis and the exploration of recombination events during recurrent infections. The virulence genotype vacAs1m1/cagA+/cagE+/babA2 was present at a high frequency, as were the EPIYA motifs EPIYA-A, −B and -C. Furthermore, the housekeeping genes of the H. pylori strains exhibited high genetic variation, comprising 26 new alleles and 17 new Sequence Type (ST). In addition, the hpEurope (76.5%) and hspWAfrica (23.5%) populations predominated among the paediatric strains. All strains, regardless of their ancestral affiliation, harboured western EPIYA motifs.

Conclusions

This study provides evidence of the evolutionary dynamics of the H. pylori strains in two paediatric patients during recrudescence and reinfection events. In particular, our study shows that the strains changed during these events, as evidenced by the presence of different STs that emerged before and after treatment; these changes may be due to the accumulation of mutations and recombination events during the diversification process and recolonization of the patients by different genotypes.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1554-z) contains supplementary material, which is available to authorized users.

Rate and predictive factors of Helicobacter pylori recurrence: Analysis of a screening cohort

BACKGROUND/AIM

The aim of the study was to identify the recurrence rate of Helicobacter pylori after successful eradication in an endemic area and investigate baseline and clinical factors related to the recurrence.

PATIENTS AND METHODS

H. pylori infected patients from a screening cohort of National Cancer Center between 2007 and 2012 were enrolled in the study. A total of 647 patients who were confirmed to be successfully eradicated were annually followed by screening endoscopy and rapid urease test. Median follow-up interval was 42 months. Annual recurrence rate of H. pylori was identified. Demographics, clinical factors, and endoscopic findings were compared between H. pylori recurrence group and persistently eradicated group (control group).

RESULTS

H. pylori recurrence was observed in 21 (3.25%) patients. Its annual recurrence rate was 0.91% (1.1% in males and 0.59% in females). Mean age was higher in the recurrence group than that in the control group (55.9 vs 50.7, P = 0.006). Median follow-up was shorter in the recurrence group than that in the control group (34 vs. 42.5 months, P = 0.031). In multivariate analysis, OR for H. pylori recurrence was 1.08 per each increase in age (P = 0.012). Adjusted ORs for H. pylori recurrence were 0.20 (95% CI: 0.06-0.69) and 0.25 (95% CI: 0.08-0.76) in age groups of 50-59 years and less than 50 years, respectively, compared to the group aged 60 years or older.

CONCLUSION

H. pylori recurrence rate in Korea is very low after successful eradication. Advanced age is at increased risk for H. pylori recurrence. Thus, H. pylori treatment for patients who are under 60 years of age is more effective, leading to maintenance of successful eradication status.

Helicobacter pylori, transmission routes and recurrence of infection: state of the art

Helicobacter pylori (H. pylori) infection is one of the most common infection in humans, affecting more than half of the population. The prevalence of the infection varies widely in rural developing areas (more than 80%) compared to urban developed ones (less than 40%), as a consequence of different socioeconomic and hygienic conditions. H. pylori infection is usually acquired during childhood; infected people usually remain asymptomatic, but about 30% of individuals may develop mild to severe upper gastrointestinal diseases such as gastritis, peptic ulcer, gastric cancer or MALT lymphoma. The transmission route is not clear yet; the person-to-person transmission, especially within the same family appears to be prevalent, but also environmental contamination is possible. The eradication without a specific therapeutic regimen is very unlikely and the reinfection rate after an effective eradication therapy is quite rare. The reinfection rate will increase if there are family members affected.

Systematic review with meta-analysis: the global recurrence rate of Helicobacter pylori

BACKGROUND

Up-to-date information regarding the recurrence rate of Helicobacter pylori (H. pylori) after eradication therapy is not available.

AIM

To evaluate the global recurrence rate following H. pylori eradication therapy and confirm its association with socioeconomic and sanitary conditions.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane library was performed to identify potentially relevant publications using the following keywords: "Helicobacter pylori" or "H. pylori" or "Hp" and "recurrence" or "recrudescence" or "reinfection" or "recurrent" or "recurred" or "re-infect*" or "relapse*."

RESULTS

A total of 132 studies (53 934 patient-years) were analysed. Each study was weighted according to the duration of patient-years. The global annual recurrence, reinfection and recrudescence rate of H. pylori were 4.3% (95% CI, 4-5), 3.1% (95% CI, 2-5) and 2.2% (95% CI, 1-3), respectively. The H. pylori recurrence rate was inversely related to the human development index (HDI) (ie, 3.1% [95% CI, 2-4], 6.2% [95% CI, 4-8] and 10.9% [95% CI, 6-18] in countries with a very high, high and medium or low HDI) (P <.01) and directly related to H. pylori prevalence (10.9% [95% CI, 7-16], 3.7% [95% CI, 3-5], 3.4% [95% CI, 2-5] and 1.6% [95% CI, 0.5-3] in countries with a very high, high, medium or low local H. pylori prevalence) (P <.01). Global recurrence rates remained relatively stable between 1990s, 2000s and 2010s but varied across different regions (P <.05).

CONCLUSIONS

H. pylori recurrence remains a problem closely associated with socioeconomic and sanitary conditions. Methods to reduce recurrence in developing countries are needed.

Diagnosis of Helicobacter pylori recurrence: relapse or reinfection? Usefulness of molecular tools

BACKGROUND AND AIMS

Infection due to Helicobacter pylori causes many gastrointestinal diseases including peptic ulcers and gastric carcinoma. Their treatment and prevention depends on the successful eradication of H. pylori. However, even after a well-conducted treatment, H. pylori persists in about 10-30% of patients. Recurrent infections can correspond to relapse or to re-infection and require appropriate medical care. In this study, we explore retrospectively three clinical cases using molecular methods, and propose new guidelines for the diagnosis of recurrence.

MATERIAL AND METHODS

Ten colonies of H. pylori were selected from the primary culture of biopsy samples taken from the antrum and fundus for each patient. The genotype of each isolated colony was determined by analyzing the polymorphism of two housekeeping genes, hspA and glmM. The genome-wide composition of H. pylori strains was studied using in house macro-arrays designed.

RESULTS

Relapses were demonstrated by the stability of genotypes and the slight genetic variability of strains on macro-arrays. Two patients suffered from relapses, one and three years after H. pylori treatment. For the third patient, both the polymorphism of glmM and hspA genotypes and the diversity of CDSs identified on macro-arrays suggested that several episodes of re-infection occurred, 1-8 years after eradication.

CONCLUSION

For the three clinical cases, molecular methods allowed identifying the causes of recurrent infections. We suggest to study genotype to distinguish between relapse and re-infection in order to adapt the treatment and the follow-up of patients to the nature of recurrence.

High rate of Helicobacter pylori reinfection in Lithuanian peptic ulcer patients

AIM: To evaluate the frequency of Helicobacter pylori (H. pylori) reinfection in peptic ulcer patients during 9 years after H. pylori eradication.

METHODS: We invited 117 peptic ulcer patients in whom eradication of H. pylori was confirmed 1 year after eradication treatment both by histology and by rapid urease test. In total, 57 patients were available for the study procedures: 34 (59.6%) male, 23 (40.4%) female; mean age 52.3 ± 13.0 years. There were 45 (78.9%) patients with duodenal ulcer and 12 (21.1%) with gastric ulcer. H. pylori was diagnosed by a rapid urease test and histology if endoscopy was performed. If endoscopy was refused, H. pylori was diagnosed by the C14-urea breath test and serology. H. pylori was established if at least one of the tests was positive.

RESULTS: The mean follow-up was 8.9 ± 1.0 years (range, 6-12). H. pylori was established in 15 patients. In 2 H. pylori-negative patients, H. pylori was established during the follow-up period and eradicated. Therefore, we consider that reinfection occurred in 17 patients. In the per protocol analysis, reinfection was established in 17 of 57 (29.8%; 95%CI: 19.2-42.2) patients during the follow-up period. The annual rate of infection was 3.36%. If all non-responders were considered H. pylori-negative, reinfection would be 14.5% (17/117), the annual rate being 1.63%. The mean age of patients with reinfection was 51.8 ± 14.0 years, and without reinfection was 52.5 ± 13.0 years, P > 0.05; the mean body mass index of patients with reinfection was 27.2 ± 4.1 kg/m², and without reinfection was 25.7 ± 4.2 kg/m², P > 0.05. There were no differences in the reinfection rates according the location of the peptic ulcer, the eradication regimen used, and smoking status.

CONCLUSION: The reinfection rate of H. pylori is relatively high in Lithuania and probably related to the high prevalence of H. pylori, what may reflect differences in the socioeconomic status between Western and Eastern European countries.

Follow-up of Helicobacter pylori infection in children over two decades (1988-2007): persistence, relapse and acquisition rates

Helicobacter pylori culture on gastric biopsy was performed on 4964 subjects aged <18 years from 1988 to 2007 at a central laboratory in Brussels. The total number of biopsies increased markedly from 941 in 1988-1993 to 1608 in 2004-2007. Biopsies were repeated at least once for 922 subjects (603 initially negative and 319 initially positive for H. pylori). Persistence rate of H. pylori at 1 year after initial positive biopsy was greater in the 1998-2007 cohort than in the 1988-1997 cohort (72.7% vs. 45.8%, P = 0.002), suggesting a tailored selection of candidates for biopsy with non-invasive tests (13C urea breath test). Of 68 subjects initially positive and re-examined subsequently after a documented cure, re-infection/relapse rate was 48.6% within 5 years post-elimination of H. pylori. Acquisition rate over 10 years follow-up in the initially negative cohort (603 patients) was 38.7% (re-infection/relapse vs. acquisition: P < 0.001). Multivariate analysis showed a fourfold greater risk of H. pylori acquisition in children of non-European origin vs. European origin (P < 0.001). Clarithromycin and metronidazole susceptibility were determined in 226 and 223 paired positive cultures in cases of re-infection/relapse or persistence. An initial non-susceptibility profile was highly predictive of a subsequent non-susceptibility profile, and the non-susceptible proportion increased markedly from 13.3% to 21.2% for clarithromycin (P < 0.001) and from 27.3% to 35.0% for metronidazole (P = 0.014), with no difference regarding European or non-European origin.

Epidemiology of Helicobacter pylori infection in six Latin American countries (SWOG Trial S0701)

OBJECTIVE

To investigate the potential determinants of Helicobacter pylori infection between adults 21-65 years old.

METHODS

Data are from the initial screening visit of a randomized clinical trial of three antibiotic regimens to eradicate H. pylori, conducted in seven sites (Santiago-Chile, Túquerres-Colombia, Guanacaste-Costa Rica, Copán-Honduras, Obregón and Tapachula-México, León-Nicaragua). Thousand eight hundred and fifty-nine adults from the general population were screened for H. pylori infection using an urea breath test (UBT) and were interviewed to assess socioeconomic-, demographic-, and symptom-related characteristics. Logistic regression was used to assess the relationship between these characteristics and H. pylori positivity at enrollment.

RESULTS

Among the 1,852 eligible participants for whom a conclusive UBT result was obtained, H. pylori prevalence was 79.4 %, ranging from 70.1 to 84.7 % among the seven centers. Prevalence did not differ by sex (female: 78.4, male: 80.9; p = 0.20) or age (p = 0.08). H. pylori positivity increased with increasing number of siblings (p trend <0.0001). Participants with education beyond 12 years were less likely to be UBT-positive (OR 0.4: 0.3-0.6, compared to participants with 0-6 years of schooling) as were those employed outside the home (OR 0.7: 0.6-1.0). Odds of H. pylori infection increased with the presence of certain living conditions during childhood including having lived in a household with an earth floor (OR 1.8: 1.4-2.4), lack of indoor plumbing (OR 1.3: 1.0-1.8) and crowding (OR 1.4: 1.0-1.8, for having more than two persons per bedroom). Regarding current household conditions, living with more than 3 children in the household (OR 1.7: 1.2-2.5) and crowding (OR 1.8: 1.3-2.3) were associated with H. pylori infection.

CONCLUSIONS

The prevalence of H. pylori in adults was high and differed significantly among the six Latin American countries studied (p < 0.001). Our findings confirm the strong link between poor socioeconomic conditions and H. pylori infection.

Helicobacter pylori neutrophil activating protein as target for new drugs against H. pylori inflammation

Helicobacter pylori (H. pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer. Within this work we present the implication of C-terminal region of H. pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evidence that the C-terminal region of H. pylori activating protein is indispensable for neutrophil adhesion to endothelial cells, a step necessary to H. pylori inflammation. In addition we show that arabino galactan proteins derived from chios mastic gum, the natural resin of the plant Pistacia lentiscus var. Chia inhibit neutrophil activation in vitro.

[Helicobacter pylori -- 2010]

Helicobacter pylori, discovered 27 years ago, has remained the most prevalent infectious agent in the world. In the author's hypothesis, the increase of peptic ulcer prevalence in the 19-20th century could be attributable to the extended worldwide use of gastric tubes for secretory testing which led to the iatrogenic transmission of pathogenic strains. Helicobacter pylori outer membrane proteins (OMP), and duodenal ulcer promoting (dupA) proteins were identified as novel virulence factors, leading to the production of pro-inflammatory cytokines, which could be future targets of therapy. There is no ideal first-line eradication of the infection and according to expert's opinion, the efficiency of these regimens has fallen gradually in recent years to unacceptably low levels; however, in the author's opinion this is a multifactorial phenomenon which can not be generalized. As alternative drugs, the efficiency of levofloxacin, furazolidone and rifabutin has been proven by meta-analyses. Sequential and bismuth-free quadruple therapies, although highly efficient, are not yet used on a large scale. The recurrence of the infection is 2.27%/year in developed and of 13.0%/year in developing countries. Spontaneous eradication occurred in 8-20% of the children and 5-11% of adults. The prevalence of clarithromycin resistance is increasing worldwide. In Hungary, it has reached 10.9% in county cities, according to a national survey. In a district of Budapest called Ferencváros, the prevalence between 2005 and 2009 was 16-22%, with no increasing trend. The development of enzymatic inhibitors (urease, carbonic anhydrase and gamma-glutamyl transpeptidase), modified antibiotics and efflux pump inhibitors seem promising ways because these compounds do not lead to resistance; however, none have yet been used in humans.