Predominance of mother-to-child transmission of Helicobacter pylori infection detected by random amplified polymorphic DNA fingerprinting analysis in Japanese families

Prevalence of Oral Helicobacter pylori Infection in an Indigenous Community in Southwest Mexico

Purpose

Epidemiological studies have been conducted to improve the health and economic quality of life of indigenous communities in Mexico. These studies have found that infections cause frequent health problems. Helicobacter pylori are responsible for conditions ranging from gastritis to stomach cancer. This study determined the prevalence of H. pylori in families from Siltepec, Chiapas, Mexico.

Patient and Methods

Ninety-nine dental plaque samples from 36 families were studied. Real-time PCR was performed to detect H. pylori using previously reported primers. The Mann-Whitney U-test was used for the statistical analysis. According to the family role of H. pylori-positive individuals, the VacA s1/m1 genotype and CagA gene correlated.

Results

The mother had the highest expression of VacA s1/m1-/cagA- with 19% (8/42), followed by the first child with 14.3% (6/42). The major roles for the vacA s1/m1+/cagA- were the mother and first child with 9.5% (4/42), followed by the remaining children with 4.8% (2/42). The vacA s1/m1-/cagA+ genotype was 7.1% (3/42) for the mother and 4.8% (2/42) for the father. Finally, the vacA s1/m1+/cagA+ genotype only appeared in the mother, son I, and son III with 2.4% (1/42).

Conclusion

The vacA s1/m1/cagA genotypes predominated in the mother, suggesting potential transmission between the mother and child during the first years of life.

Intracellular presence and genetic relationship of Helicobacter pylori within neonates' fecal yeasts and their mothers' vaginal yeasts

Helicobacter pylori are transmissible from person to person and among family members. Mother-to-child transmission is the main intrafamilial route of H. pylori transmission. However, how it transmits from mother to child is still being determined. Vaginal yeast often transmits to neonates during delivery. Therefore, H. pylori hosted in yeast might follow the same transmission route. This study aimed to detect intracellular H. pylori in vaginal and fecal yeasts isolates and explore the role of yeast in H. pylori transmission. Yeast was isolated from the mothers' vaginal discharge and neonates' feces and identified by internal transcribed spacer (ITS) sequencing. H. pylori 16S rRNA and antigen were detected in yeast isolates by polymerase chain reaction and direct immunofluorescence assay. Genetic relationships of Candida strains isolated from seven mothers and their corresponding neonates were determined by random amplified polymorphic DNA (RAPD) fingerprinting and ITS alignment. The Candida isolates from four mother-neonate pairs had identical RAPD patterns and highly homologous ITS sequences. The current study showed H. pylori could be sheltered within yeast colonizing the vagina, and fecal yeast from neonates is genetically related to the vaginal yeast from their mothers. Thus, vaginal yeast presents a potential reservoir of H. pylori and plays a vital role in the transmission from mother to neonate.

Large-scale, national, family-based epidemiological study on Helicobacter pylori infection in China: the time to change practice for related disease prevention

BACKGROUND AND AIMS

Current practice on Helicobacter pylori infection mostly focuses on individual-based care in the community, but family-based H. pylori management has recently been suggested as a better strategy for infection control. However, the family-based H. pylori infection status, risk factors and transmission pattern remain to be elucidated.

METHODS

From September 2021 to December 2021, 10 735 families (31 098 individuals) were enrolled from 29 of 31 provinces in mainland China to examine family-based H. pylori infection, related factors and transmission pattern. All family members were required to answer questionnaires and test for H. pylori infection.

RESULTS

Among all participants, the average individual-based H. pylori infection rate was 40.66%, with 43.45% for adults and 20.55% for children and adolescents. Family-based infection rates ranged from 50.27% to 85.06% among the 29 provinces, with an average rate of 71.21%. In 28.87% (3099/10 735) of enrolled families, there were no infections; the remaining 71.13% (7636/10 735) of families had 1-7 infected members, and in 19.70% (1504/7636), all members were infected. Among 7961 enrolled couples, 33.21% had no infection, but in 22.99%, both were infected. Childhood infection was significantly associated with parental infection. Independent risk factors for household infection were infected family members (eg, five infected members: OR 2.72, 95% CI 1.86 to 4.00), living in highly infected areas (eg, northwest China: OR 1.83, 95% CI 1.57 to 2.13), and large families in a household (eg, family of three: OR 1.97, 95% CI 1.76 to 2.21). However, family members with higher education and income levels (OR 0.85, 95% CI 0.79 to 0.91), using serving spoons or chopsticks, more generations in a household (eg, three generations: OR 0.79, 95% CI 0.68 to 0.92), and who were younger (OR 0.57, 95% CI 0.46 to 0.70) had lower infection rates (p<0.05).

CONCLUSION

Familial H. pylori infection rate is high in general household in China. Exposure to infected family members is likely the major source of its spread. These results provide supporting evidence for the strategic changes from H. pylori individual-based treatment to family-based management, and the notion has important clinical and public health implications for infection control and related disease prevention.

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

The Effectiveness of Different Eradication Schemes for Pediatric Helicobacter pylori Infection—A Single-Center Comparative Study from Romania

Introduction: In Romania, studies on the pediatric population regarding H. pylori infection or bacterial resistance to antibiotics are limited. Eradication treatment of this infection still raises important problems in medical practice. This study aims to compare the effectiveness of three eradication therapies used against H. pylori infection in the pediatric population. Methods: The prospective study enrolled children aged 6–17 years who were first diagnosed with H. pylori infection. Patients received a randomized treatment either the therapy with clarithromycin (CLR), the therapy with metronidazole (MTZ) or sequential therapy. The effectiveness of the eradication treatment was evaluated after 4–8 weeks from the end of the therapy by testing fecal antigen. Results: 149 patients were enrolled over 18 months. The eradication rates were 49.5% for the treatment scheme with proton pump inhibitor (PPI) + amoxicillin (AMO) + MTZ, 26.7% for PPI + AMO + CLR and 23.8% for sequential therapy. MTZ therapy was superior to CLR therapy, but sequential therapy was not. Side effects were recorded for PPI + AMO + CLR with 39.6%, followed by sequential therapy 37.7%, and only 22.6% for PPI + AMO + MTZ. Conclusions: Therapy with MTZ can achieve a higher eradication rate as a first-line treatment in the case of H. pylori infection. Taking into account that Romania is in an area with increased resistance to CLR, MTZ therapy could be a promising alternative.

Family-based Helicobacter pylori infection status and transmission pattern in central China, and its clinical implications for related disease prevention

BACKGROUND

Helicobacter pylori (H. pylori) has characteristics of family cluster infection; however, its family-based infection status, related factors, and transmission pattern in central China, a high-risk area for H. pylori infection and gastric cancer, have not been evaluated. We investigated family-based H. pylori infection in healthy households to understand its infection status, related factors, and patterns of transmission for related disease prevention.

AIM

To investigate family-based H. pylori infection status, related factors, and patterns of transmission in healthy households for related disease prevention.

METHODS

Blood samples and survey questionnaires were collected from 282 families including 772 individuals. The recruited families were from 10 selected communities in the greater Zhengzhou area with different living standards, and the family members’ general data, H. pylori infection status, related factors, and transmission pattern were analyzed. H. pylori infection was confirmed primarily by serum H. pylori antibody arrays; if patients previously underwent H. pylori eradication therapy, an additional ¹³C-urea breath test was performed to obtain their current infection status. Serum gastrin and pepsinogens (PGs) were also analyzed.

RESULTS

Among the 772 individuals examined, H. pylori infection rate was 54.27%. These infected individuals were from 246 families, accounting for 87.23% of all 282 families examined, and 34.55% of these families were infected by the same strains. In 27.24% of infected families, all members were infected, and 68.66% of them were infected with type I strains. Among the 244 families that included both husband and wife, spouse co-infection rate was 34.84%, and in only 17.21% of these spouses, none were infected. The infection rate increased with duration of marriage, but annual household income, history of smoking, history of alcohol consumption, dining location, presence of gastrointestinal symptoms, and family history of gastric disease or GC did not affect infection rates; however, individuals who had a higher education level showed lower infection rates. The levels of gastrin-17, PGI, and PGII were significantly higher, and PGI/II ratio was significantly lower in H. pylori-infected groups than in H. pylori-negative groups.

CONCLUSION

In our study sample from the general public of central China, H. pylori infection rate was 54.27%, but in 87.23% of healthy households, there was at least 1 H. pylori-infected person; in 27.24% of these infected families, all members were infected. Type I H. pylori was the dominant strain in this area. Individuals with a higher education level showed significantly lower infection rates; no other variables affected infection rates.

Serum pepsinogen cut-off values in Helicobacter pylori-infected children

BACKGROUND

The aim of this study was to evaluate the standard values for gender- and age-stratified serum pepsinogen (sPG) in Helicobacter pylori (H. pylori) non-infected children and to determine the optimal cut-off values of sPG for predicting H. pylori-infected gastritis in children.

METHODS

A prospective study for determination of sPG levels was performed in children with epigastric pain who underwent esophagogastroduodenoscopy over the past 16 years. After excluding subjects diagnosed with inflammatory bowel diseases, eosinophilic gastrointestinal disorders, or immunoglobulin A vasculitis, the diagnosis of H. pylori infection was defined by positive tissue culture or concordant-positive results for histology and the rapid urease test.

RESULTS

A total of 405 subjects were diagnosed as being H. pylori-infected (79) or non-infected (326). In the H. pylori non-infected group, there were no significant differences in sPG levels among age groups; males had higher sPG I and sPG II levels than females. In the H. pylori-infected group, sPG I and sPG II levels were significantly higher and the sPG I/II ratio was lower than those in the non-infected group. In receiver operating characteristics analyses in diagnosing H. pylori infection, the areas under the curves for sPG I, sPG II and sPG I/II ratio were 0.896, 0.980, and 0.946, respectively. The optimal cut-off value of sPG II of ≥9.0 ng/mL was considered positive for H. pylori infection (sensitivity: 92.4%, specificity: 93.9%).

CONCLUSIONS

The optimal cut-off value of sPG II of ≥9.0 ng/mL may be a good predictor of H. pylori-infected gastritis in children.

The role of the occupational physician in controlling gastric cancer attributable to Helicobacter pylori infection: A review

This review aimed to describe the potential role of occupational physician in the implementation of a screening program for Helicobacter pylori (Hp) infection for gastric cancer prevention. We reviewed the epidemiological background of gastric cancer and its association with Hp, exploring the hypothesis of a "test-and-treat" protocol among working population. Clinical trials and model-based studies were collected to provided empirical evidence of the feasibility of eradication on large scale. In particular, previous studies conducted in occupational settings were discussed. Hp prevalence ranges between about 20 and 90%, with higher rates in Asia and Latin America and lower rates in Europe and North America. Large-scale trials on screening and treatment of infection have been conducted especially in East Asia, lacking elsewhere. Only few studies investigated Hp prevalence among workers. The benefit of eradication at occupational level has not yet been adequately studied. The design of a workplace-based Hp screening program appears to be innovative and could contribute to controlling gastric cancer. The benefit would involve not only high-risk subjects, but also their families, since the route of transmission is principally within the household. An occupational setting for a Hp screening would have positive consequences in terms of individual and public health.

Antimicrobial activity and additive effect of the modified Gingyo-san with antimicrobials against Helicobacter pylori

INTRODUCTION

Helicobacter pylori is an important factor in the development of gastroduodenal ulcers and gastric cancer. Although H. pylori eradication therapy has been employed, the eradication rate has decreased in recent years owing to an increase in clarithromycin-resistant strains. We previously reported the anti-infective effect of herbal medicines against several bacterial species. Here, we evaluated the growth inhibitory activity of herbal medicines alone and in combination with antimicrobials against H. pylori.

METHODS AND RESULTS

Nine of 37 herbal medicines inhibited the growth of H. pylori ATCC700392. In particular, modified Gingyo-san showed the strongest growth inhibitory activity with a minimum inhibitory concentration (MIC) of 512 μg/ml for not only ATCC700392 but also clarithromycin-resistant strains having a 23 S rRNA mutation. Results of Time-Kill Kinetics Assay showed that 1 mg/mL modified Gingyo-san treatment for one hour killed 50% of the H. pylori population. Furthermore, modified Gingyo-san showed additive effects with clarithromycin, amoxicillin, and metronidazole against H. pylori ATCC700392 and clarithromycin-resistant strains.

CONCLUSIONS

Our findings showed that modified Gingyo-san inhibits the growth of H. pylori and improves antimicrobial susceptibility when used in combination. Therefore, modified Gingyo-san has the potential to enhance the eradication rate of clarithromycin-resistant H. pylori.

Association between parental history of Helicobacter pylori treatment failure and treatment failure in the offspring

BACKGROUND AND AIM

Both clarithromycin-resistant Helicobacter pylori and CYP2C19 polymorphisms may be passed down for generations and are known risk factors for the failure of H. pylori eradication therapy. However, no study has evaluated the risk of clarithromycin triple therapy failure in patients with a parental history of such failure. This study investigated the association between a history of clarithromycin triple therapy failure in parents and clarithromycin triple therapy failure in the offspring.

METHODS

This cross-sectional study was conducted using a large administrative claims database of 3 100 000 insured individuals. We identified 404 patients who had both personal and parental records of prescriptions for first-line clarithromycin triple therapy between January 2005 and February 2018. Failure of clarithromycin triple therapy was defined as treatment with second-line therapy after having received first-line clarithromycin triple therapy. A parental history of clarithromycin triple therapy failure was defined as failure of clarithromycin triple therapy by either the father or the mother. Odds ratios were estimated using logistic regression models adjusted for age, sex, diabetes mellitus, and peptic ulcer.

RESULTS

The incidence of clarithromycin triple therapy failure was 22.5% (91/404). Based on univariate analysis (odds ratio [95% confidence interval], 1.90 [1.10-3.29]) and multivariable analysis (odds ratio [95% confidence interval], 1.93 [1.10-3.39]), parental history of clarithromycin triple therapy failure was associated with failure of clarithromycin triple therapy in the offspring.

CONCLUSION

A parental history of clarithromycin triple therapy failure is a risk factor for failure of clarithromycin triple therapy in the offspring.

Helicobacter pylori infection in rehabilitation staff younger than 35 years: Infection surveillance for three years

Background:

Screening for Helicobacter pylori infection is important because of the high risk of gastric cancer development. The H. pylori carrier rate among elderly Japanese patients is still high; therefore, rehabilitation (RH) workers who are in frequent contact with such individuals could be assumed to be at a higher risk of H. pylori infection.

Aim/Objective:

We surveyed RH workers to investigate the initial occurrence of H. pylori infections in adults.

Methods:

Urine samples of RH workers aged < 35 years were screened for H. pylori antibodies to confirm infection. H. pylori infection rates were stratified according to the type of RH work and duration of employment. Infection surveillance was performed at six-month intervals for H. pylori-negative individuals.

Findings/Results:

The H. pylori infection rate among 173 workers was 16.8%. Infection rates were 26.3%, 16.3% and 15.3% among speech, occupational and physiotherapists, respectively. The employment duration was divided into < 24, 24–47, 48–60 and ⩾ 61 months; the respective infection rates were 5.0%, 12.0%, 17.6% and 28.6%. However, no new H. pylori infection was detected in a total of seven surveillance studies of H. pylori-negative workers over a three-year period.

Discussion:

The results of the initial examination showed that the infection rate increased with the duration of employment. However, subsequent surveillance detected no new H. pylori infections.

Guidelines for the management of Helicobacter pylori infection in Japan: 2016 Revised Edition

BACKGROUND

Since "Helicobacter pylori (H. pylori) infection" was set as the indication in the Japanese Society for Helicobacter Research (JSHR) Guidelines 2009, eradication treatment for H. pylori gastritis is covered under insurance since 2013 in Japan, and the number of H. pylori eradication has rapidly increased. Under such circumstances, JSHR has made the third revision to the "Guidelines for diagnosis and treatment of H. pylori infection" for the first time in 7 years.

METHODS

The Guideline Committee held 10 meetings. Articles published between the establishment of the 2009 Guidelines and March 2016 were reviewed and classified according to the evidence level; the statements were revised on the basis of this review. After inviting public comments, the revised statements were finalized using the Delphi method.

RESULTS

There was no change in the basic policy that H. pylori infectious disease is an indication for eradication. Other diseases presumed to be associated with H. pylori infection were added as indications. Serum pepsinogen level, endoscopic examination, and X-ray examination were added to the diagnostic methods. The effects of 1-week triple therapy consisting of potassium-competitive acid blocker (P-CAB), amoxicillin, and clarithromycin have improved, and high eradication rates can also be expected with proton pump inhibitors (PPI) or P-CAB combined with amoxicillin and metronidazole. If the susceptibility test is not performed, the triple PPI or P-CAB/amoxicillin/metronidazole therapy should be chosen, because the PPI/amoxicillin/metronidazole combination demonstrated a significantly higher eradication rate than PPI/amoxicillin/clarithromycin. In the proposal for gastric cancer prevention, we divided gastric cancer prevention measures by age from adolescent to elderly, who are at an increased gastric cancer risk, and presented measures for gastric cancer prevention primarily based on H. pylori eradication.

CONCLUSION

We expect the revised guidelines to facilitate appropriate interventions for patients with H. pylori infection and accomplish its eradication and prevention of gastric cancer.

Enhanced infectivity of strains of Helicobacter pylori isolated from children compared with parental strains

PURPOSE

Intra-familial infection, mother-to-child infection, is considered to be one of the main routes of transmission for Helicobacter pylori, in developed countries such as Japan. A major role for intra-familial spread in the pathogenicity of H. pylori is now beyond controversy, although the major route of transmission remains poorly understood. We performed this study to clarify the factors determining intra-familial transmission.

METHODOLOGY

We used several H. pylori strains isolated from family members to compare infectivity. H. pylori K21 and K22 strains were isolated from the father and mother, and the K25 strain was isolated from the third child of the family. Mongolian gerbils were inoculated with H. pylori strains and the infectivity of three strains was compared in each experiment. In addition, the whole genome sequence, adhesion to gastric epithelial cells and the growth of static condition or continuous flow culture among three strains of H. pylori were analysed.Results/Key findings. Most of the colonies were determined as the same molecular type K25 in all of the four grouped animals and H. pylori K25 was observed as the dominant strain. The stronger adhesion capacity of the K25 strain was observed in comparison with the other two strains through in vitro analysis. By assessing the genomic profiles of H. pylori isolates from three strains, identified TnPZ regions were detected only in the K25 strain.

CONCLUSION

The infectivity of H. pylori isolates intra-familial infection and animal infection were prescribed by the adhesion capacity and molecular type of each strain.

Helicobacter pylori infection in children: an overview of diagnostic methods

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

Status of vaccine research and development for Helicobacter pylori

Gastric adenocarcinoma is globally the third leading cause of death due to malignancy, with the bulk of this disease burden being suffered by low and middle income countries (LMIC), especially in Asia. The majority of these cancers develop as a result of a chronic gastritis that arises in response to infection with the stomach-dwelling bacterium, Helicobacter pylori. A vaccine against this pathogen would therefore be a powerful tool for preventing gastric adenocarcinoma. However, notwithstanding a proof-of-concept that vaccination can protect children from acquisition of H. pylori infection, there are currently no advanced vaccine candidates with only a single vaccine in Phase I clinical trial. Further, the development of a vaccine against H. pylori is not a current strategic priority of major pharmaceutical companies despite the large global disease burden. Given the involvement of such companies is likely to be critical for late stage development, there is therefore a need for an increased appreciation of the burden of this disease in LMIC and more investment to reinvigorate research in H. pylori vaccine Research and Development.

Influence of Intestinal Indigenous Microbiota on Intrafamilial Infection by Helicobacter pylori in Japan

Helicobacter pylori is a causative pathogen of chronic gastritis, gastric ulcer disease, and gastric cancer. Humans are known to be a natural host for H. pylori and tend to acquire the pathogen before the age of 5 years. The infection may then persist lifelong if eradication therapy is not applied. One of the modes of transmission of H. pylori is between family members, and therefore, the presence of infected family members is an important risk factor in children. However, other environmental factors have not been fully analyzed. The present study was performed to clarify whether and to what extent intestinal microbiota affect H. pylori intrafamilial infection. The fecal specimens from H. pylori-infected infants and H. pylori-infected and non-infected family members were collected in cohort studies conducted by Sasayama City, Hyogo Prefecture from 2010 to 2013. In total, 18 fecal DNA from 5 families were analyzed. Samples were amplified using 16S rRNA universal primers, and the amplicons were sequenced using the Ion PGM system. Principal-coordinate analysis demonstrated that there was no difference in intestinal microbiota between H. pylori-positive and H. pylori-negative groups. In intrafamilial comparison tests, the Manhattan distance of intestinal microbiota between the H. pylori-infected infant proband and H. pylori-negative mother was nearest in the family with low intestinal microbial diversity. However, in the family with the highest intestinal microbial diversity, the nearest Manhattan distance was shown between the H. pylori-infected infant proband and H. pylori-infected mother. The results in this study showed that the composition of the intestinal microbiota was very similar between members of the same family, and as such, colonization with organisms highly similar to the infected parent(s) may be a risk factor for H. pylori infection in children.

Helicobacter pylori-induced gastric pathology: insights from in vivo and ex vivo models

Gastric colonization with Helicobacter pylori induces diverse human pathological conditions, including superficial gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma and its precursors. The treatment of these conditions often relies on the eradication of H. pylori, an intervention that is increasingly difficult to achieve and that does not prevent disease progression in some contexts. There is, therefore, a pressing need to develop new experimental models of H. pylori-associated gastric pathology to support novel drug development in this field. Here, we review the current status of in vivo and ex vivo models of gastric H. pylori colonization, and of Helicobacter-induced gastric pathology, focusing on models of gastric pathology induced by H. pylori, Helicobacter felis and Helicobacter suis in rodents and large animals. We also discuss the more recent development of gastric organoid cultures from murine and human gastric tissue, as well as from human pluripotent stem cells, and the outcomes of H. pylori infection in these systems.

Host pathogen interactions in Helicobacter pylori related gastric cancer

Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor.

Recurrence of Helicobacter pylori infection and the affecting factors: A follow-up study

OBJECTIVE

Recurrence of Helicobacter pylori (H. pylori) infection weakens the protective effect and long-term prognosis of eradication. With the widespread therapies, decreasing prevalence of H. pylori infection and improvement in living conditions, the recurrence of H. pylori infection may present with new features. We conducted this prospective, large-scale, multicenter follow-up study to determine the recurrence rate of H. pylori infection and its affecting factors.

METHODS

A total of 827 patients receiving successful H. pylori eradication in our previous randomized controlled trial were enrolled. ¹³ C-urea breath test (UBT) was repeated one year after the eradication therapy to determine its recurrence. Moreover, a questionnaire survey was performed to explore the potential factors affecting the recurrence.

RESULTS

A total of 743 patients completed ¹³ C-UBT (follow-up rate 89.8%), and the result was positive in 13 patients one year after eradication therapy, with an annual recurrence rate of 1.75% (95% confidence interval [CI] 0.81-2.69%). Six hundred and ninety-two patients (13 with recurrence and 679 without recurrence) returned their questionnaires, with a response rate of >80%. Multivariate analysis revealed that peptic ulcer (odds ratio [OR] 3.385, 95% CI 1.016-11.274), close contact with individuals having H. pylori infection (OR 4.231, 95% CI 1.201-14.911), and hospitalization (OR 9.302, 95% CI 2.441-35.440) were independent risk factors of H. pylori infection recurrence.

CONCLUSIONS

The recurrence of H. pylori infection one year after eradication therapy is low in urban population of China. Peptic ulcer, contact history with individuals having H. pylori infection and hospitalization are risk factors.

Intrafamilial transmission of Helicobacter pylori: genotyping of faecal samples

BACKGROUND

After more than 20 years of research, there is a little information about the detailed routes of Helicobacter pylori transmission. The aim of this study was to explore intrafamilial transmission of H. pylori in children who had indication for upper gastrointestinal endoscopy and their parents.

METHODS

Children (aged up to 15 years) were studied during September 2012 to October 2013. The parents of those with positive urea breath test results were asked to provide faecal and blood samples after giving informed consent. Non-invasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in faeces were measured. The genetic similarity of the family strains was investigated by the random amplification of polymorphic DNA (RAPD-PCR) genotyping method.

RESULTS

According to the genotyping results of 30 families, in 10 (33.3%) children related H. pylori genotypes to their mothers were found, while only 2 children (6.7%) had similar genotypes to their fathers. Interestingly, children with similar H. pylori genotype with their mothers had higher IgA (35.7 ± 10.8) and IgM antibody titres (87.23 ± 19.15) than other children. In addition, in these children, lower titres of IgG antibodies (9.93 ± 3.31) were found rather than children who had no H. pylori in their faeces or had no similarities with their parents (30.28 ± 6.15).

CONCLUSIONS

In conclusion, mother-to-child transmission is the main route of intrafamilial transmission of H. pylori in Iranian families. Molecular typing of H. pylori can be useful in identifying a high-risk population.

Intrafamilial, Preferentially Mother-to-Child and Intraspousal, Helicobacter pylori Infection in Japan Determined by Mutilocus Sequence Typing and Random Amplified Polymorphic DNA Fingerprinting

BACKGROUND

The infection route of Helicobacter pylori has been recognized to be mainly intrafamilial, preferentially mother-to-child, especially in developed countries. To determine the transmission route, we examined whether multilocus sequence typing (MLST) was useful for analysis of intrafamilial infection. The possibility of intraspousal infection was also evaluated.

MATERIALS AND METHODS

Clonal relationships between strains derived from 35 index Japanese pediatric patients, and their family members were analyzed by two genetic typing procedures, MLST and random amplified polymorphic DNA (RAPD) fingerprinting.

RESULTS

Mostly coincident results were obtained by MLST and RAPD. By MLST, the allele of loci in the isolates mostly matched between the index child and both the father and mother for 9 (25.7%) of the 35 patients, between the index child and the mother for 25 (60.0%) of the 35 patients.

CONCLUSIONS

MLST is useful for analyzing the infection route of H. pylori as a highly reproducible method. Intrafamilial, especially mother-to-children and sibling, infection is the dominant transmission route. Intraspousal infection is also thought to occur in about a quarter in the Japanese families.

Screening to Identify and Eradicate Helicobacter pylori Infection in Teenagers in Japan

The purpose of this study was to elucidate the prevalence and effect of Helicobacter pylori infection in Japanese teenagers. The study subjects were students ages 16 to 17 from one high school studied between 2007 and 2013. Students who tested positive on this screening examination underwent esophagogastroduodenoscopy and biopsy samples to determine their H pylori status using culture and histology. Cure of H pylori infections was determined by urea breath test. The low rate of prevalence of H pylori infection in present Japanese teenagers makes it possible and cost effective to perform examinations and carry out treatment of this infection in nationwide health screenings of high school students.

Seventeen-year effects of eradicating Helicobacter pylori on the prevention of gastric cancer in patients with peptic ulcer; a prospective cohort study

BACKGROUND

We previously reported that eradication of Helicobacter pylori in our cohort of patients with peptic ulcer disease reduced their risk of developing gastric cancer to approximately one-third after a mean follow-up period of 3.4 years (up to 8.6 years). We have now followed these patients for a longer period.

METHODS

A total of 1,222 consecutive patients with peptic ulcer diseases who completed more than 1-year follow-up after receiving H. pylori eradication therapy were followed with annual endoscopic surveillance for a mean of 9.9 years (as long as 17.4 years).

RESULTS

H. pylori infection was judged cured in 1,030 patients (eradication-success group) but persisted in 192 (eradication-failure group) after initial eradication therapy. In the eradication-failure group, 114 patients received re-treatment at a mean of 4.4 years after the start of follow-up, and 105 of these were cured of infection. Gastric cancer developed in 21 of the 1,030 patients in the eradication-success group and in nine of the 192 in the failure group (p = 0.04). The risk of developing gastric cancer in the eradication-success group (0.21 %/year) was significantly lower than that in the failure group (0.45 %, p = 0.049). The longest interval between the initial H. pylori eradication and the occurrence of gastric cancer was 14.5 years in the eradication-success group and 13.7 years in the eradication-failure group.

CONCLUSIONS

A prophylactic effect for gastric cancer persists for more than 10 years after H. pylori eradication therapy, but we should be aware that cancer can develop even after that interval.

Low prevalence and incidence of Helicobacter pylori infection in children: a population-based study in Japan

BACKGROUND

Infection of Helicobacter pylori mainly occurs in childhood. In Japan, incidence of gastric cancer is still high in the senior citizen population, but little is known about the current H. pylori infection status among children or their family members.

METHODS

As a population-based study, the prevalence of H. pylori infection and change in infection status over a 1-year interval in children were determined. Family members of some participants were also invited to participate in the study to determine their infection status. All children of specific ages attending 16 schools in Sasayama, Hyogo Prefecture, were invited to participate. H. pylori infection was determined by the stool antigen test and diagnosis confirmed by polymerase chain reaction and the urea breath test.

RESULTS

Helicobacter pylori prevalence was 1.9% among 689 children aged 0-8 years in 2010 and 1.8% among 835 children aged 0-11 in 2011. No feco-conversion was observed in 430 children aged 0-8 years (170 were aged 0-4 years) who provided follow-up stool samples after 1 year. The prevalence of infection was 6% (2 of 33) and 38% (6 of 16) in mothers of negative and positive probands (p = .04), respectively, and 12% (3 of 25) and 50% (8 of 16) (p = .01), respectively, in fathers.

CONCLUSION

Helicobacter pylori prevalence in Japanese children is approximately 1.8%, which is much lower than that reported in Japanese adults. New infection may be rare. Parent-to-child infection is thought to be the main infection route of the infrequent infection for children in Japan.

Prevention of Helicobacter pylori infection in childhood

Helicobacter pylori (H. pylori) infection is one of the most common infections worldwide. Although infection rates are falling in the developed and developing countries, H. pylori is still widespread in the world. This article has reviewed the important publications on H. pylori in childhood with a focus on its evolving transmission route and the source of infection and preventive strategies in childhood, PubMed was searched up to identify eligible studies. Relevant publications were searched using the following.

Clonality Analysis of Helicobacter pylori in Patients Isolated from Several Biopsy Specimens and Gastric Juice in a Japanese Urban Population by Random Amplified Polymorphic DNA Fingerprinting

Background. The number of Helicobacter pylori clones infecting a single host has been discussed in numerous reports. The number has been suggested to vary depending on the regions in the world. Aim. The purpose of this study was to examine the number of clones infecting a single host in a Japanese urban population. Materials and Methods. Thirty-one Japanese patients undergoing upper gastrointestinal endoscopy were enrolled in this study. H. pylori isolates (total 104 strains) were obtained from biopsy specimens (antrum, corpus, and duodenum) and gastric juice. Clonal diversity was examined by the random amplified polymorphic DNA (RAPD) fingerprinting method. Results. The RAPD fingerprinting patterns of isolates from each patient were identical or very similar. And the isolates obtained from several patients with 5- to 9-year intervals showed identical or very similar RAPD patterns. Conclusion. Each Japanese individual of an urban population is predominantly infected with a single H. pylori clone.

Clinical practice: Helicobacter pylori infection in childhood

Helicobacter pylori infection is recognised as a cause of gastritis and peptic ulcer disease (PUD) and usually acquired during the first years of life. While there is a decline in the prevalence of H. pylori infection in northern and western European countries, the infection is still common in southern and eastern parts of Europe and Asia. Symptoms of H. pylori-related PUD are nonspecific in children and may include epigastric pain, nausea and/or vomiting, anorexia, iron deficiency anaemia and hematemesis. Besides, only a small proportion of children develop symptoms and clinically relevant gastrointestinal disease. H. pylori infection can be diagnosed either by invasive tests requiring endoscopy and biopsy or non-invasive tests including the (13)C-urea breath test, detection of H. pylori antigen in stool and detection of antibodies in serum, urine and saliva. The aim of treatment is at least 90 % eradication rate of the bacteria, and a combination of two antibiotics plus a proton pump inhibitor has been recommended as first-line treatment. However, frequent use of antibiotics during childhood is associated with a decline in eradication rates and the search for new treatment strategies as well. This is an overview of the latest knowledge and evidence-based guidelines regarding clinical presentation, diagnosis and treatment of H. pylori infection in childhood.

Multilocus sequence typing of DNA from faecal specimens for the analysis of intra-familial transmission of Helicobacter pylori

This study used multilocus sequence typing (MLST) of total DNA extracted from faecal specimens to genotype Helicobacter pylori to analyse intra-familial transmission. Faecal DNA was extracted and amplified by nested PCR. The products were analysed by direct sequencing and the allele type was determined using an MLST website. Mother-to-child transmission was suspected in at least two of three families, and father-to-child transmission was suspected in one family.

Helicobacter pylori persistence in children: distinguishing inadequate treatment, resistant organisms, and reinfection

Helicobacter pylori is a worldwide infection that causes chronic gastritis, duodenal ulcers, and malignancy. Transmission of Helicobacter pylori within a family appears to be the predominant mode of contamination. Recurrence of the infection is frequently seen following treatment. Lack of eradication due to either inadequate treatment or resistant bacteria vs. reinfection have been explanations for detection of H. pylori following treatment. In this article we will discuss the concepts of inadequate treatment vs. resistant infection and reinfection as causes of persistent H. pylori infection.

Introduction of an examination and treatment for Helicobacter pylori infection in high school health screening

BACKGROUND

Recently, a significant relationship between gastric cancer and Helicobacter pylori infection has been proven. The purpose of this study was to elucidate the actual conditions of H. pylori infection in Japanese teenagers.

METHODS

The study subjects were students at a certain high school between 2007 and 2009. They were first examined with a urinary rapid test kit based on immunochromatographic technology [corrected] for detection of the antibody to H. pylori (RAPIRAN®). [corrected]. Students who tested positive on this screening examination visited Shinshu University Hospital and received esophagogastroduodenoscopy, and biopsy samples were taken to examine their H. pylori status. The resolution of H. pylori infection was assessed by urea breath test.

RESULTS

For 3 years, 1,224 of 1,232 students (99.4%) received a screening examination for H. pylori infection. Sixty-four of these 1,224 students (5.2%) were found to be positive for H. pylori. Thirty of these 64 H. pylori-positive students visited our hospital, and 24 of them (80%) were confirmed to be infected by H. pylori. The most common endoscopic findings for students with H. pylori infection were nodular gastritis (58.3%) and closed-type atrophic gastritis (45.8%). Histological findings showed no evidence of intestinal metaplasia, except in one of the students. All 24 students were successfully cured of H. pylori infection. If this procedure were to be introduced into the nationwide health screening at Japanese high schools, we calculated that the cost of the prevention of a gastric cancer would be 454,073 yen for each person.

CONCLUSIONS

The low rate of prevalence of H. pylori infection in Japanese teenagers would make it possible to perform examinations and carry out treatment for this infection in high school health screenings from the standpoint of medical economy.

The epidemiology of Helicobacter pylori and public health implications

This article presents a review of the literature on the epidemiology and public health implications of Helicobacter pylori infection published from April 2008 through to March 2009. The authors used MeSH terms "Helicobacter infections epidemiology,""Helicobacter infections prevention and control" to search multiple databases (PubMed, Embase, Cochrane, Cochrane Library, EBMR, BIOSIS), and independently searched PubMed using the term "Helicobacter" with "Epidemiology,""Transmission,""Prevalence" or "Environment." Articles without topical relevance were excluded. Two additional papers known to the authors were added. The identified literature is summarized by subtopic: reviews; prevalence; incidence; transmission; risk factors; and public health policy.

Helicobacter pylori infection in pediatrics

his review summarizes the articles published on Helicobacter pylori infection in children between April 2008 and March 2009. Recent evidence highlights the decreasing prevalence trend of H. pylori infection and supports both intrafamilial and extrafamilial transmission. The association with various symptoms is still being debated. Interestingly, H. pylori infection seems inversely associated with allergic diseases. Monoclonal stool antigen tests are widely used and accurate for the diagnosis of H. pylori infection, but less accurate in young children. The new biprobe real-time PCR assay applied to stools showed a poor sensitivity in children. Using the urea hydrolysis rate next to the delta over baseline values, the (13)C-urea breath test provides excellent results for all age children, even for young children. Treatment of H. pylori infection remains a challenge, considering suboptimal efficacy of current therapy. Among emerging alternatives, sequential treatment appears promising. The adjunction of probiotics to conventional regimens, although eliciting great interest, has shown limited therapeutic benefit.

Comparative genomics of Helicobacter pylori

Genomic sequences have been determined for a number of strains of Helicobacter pylori (H pylori) and related bacteria. With the development of microarray analysis and the wide use of subtractive hybridization techniques, comparative studies have been carried out with respect to the interstrain differences between H pylori and inter-species differences in the genome of related bacteria. It was found that the core genome of H pylori constitutes 1111 genes that are determinants of the species properties. A great pool of auxillary genes are mainly from the categories of cag pathogenicity islands, outer membrane proteins, restriction-modification system and hypothetical proteins of unknown function. Persistence of H pylori in the human stomach leads to the diversification of the genome. Comparative genomics suggest that a host jump has occurs from humans to felines. Candidate genes specific for the development of the gastric diseases were identified. With the aid of proteomics, population genetics and other molecular methods, future comparative genomic studies would dramatically promote our understanding of the evolution, pathogenesis and microbiology of H pylori.