A population-based study of Helicobacter pylori infection in Chinese children resident in Hong Kong: prevalence and potential risk factors

Background: Data of Helicobacter pylori prevalence in children and its risk factors provide clues to the health authority to estimate burden of H. pylori‐associated diseases usually encountered in adulthood and facilitate healthcare planning. Materials and Methods: A cross‐sectional population‐based study was conducted in Chinese children in elementary and high schools. Schools were selected from all three major areas of Hong Kong. H. pylori infection was defined by a positive ¹³C‐urea breath test. Study subjects were stratified into six age groups for estimation of prevalence. Potential risk factors were analyzed from data of self‐administered questionnaires. Results: A total of 2480 children (aged 6–19, male: 47.3%) participated in the study. Overall, 324 (13.1%) were positive for H. pylori. There was no difference in prevalence between sexes, and no statistical trend in the prevalence across the six age groups. Multivariate logistic regression identified lack of formal education of mother (OR = 2.43, 95%CI 1.36–4.34), family history of gastric cancer (OR = 2.19, 95%CI 1.09–4.41), and household member > 5 (OR = 1.57, 95%CI 1.12–2.19) to be positively associated with H. pylori infection in our children. Conclusions: The H. pylori prevalence of Hong Kong children is comparable to the data of developed countries. The association with family history of gastric cancer justifies further study to investigate the cost‐benefit of community screening program for such children to decrease the incidence of gastric cancer in adulthood.     

Natural history of Helicobacter pylori infection in childhood: eight-year follow-up cohort study in an urban community in northeast of Brazil

Background: Helicobacter pylori infection is acquired predominantly in childhood. There is also evidence that children loss the infection. Therefore, factors that account for children remain infected need to be investigated because once established the infection persists throughout the life unless treated. Methods: This study aimed to evaluate the H. pylori infection in children of a low‐income community at baseline and 8 years later to determine the predictor factors linked to the maintenance, acquisition, and loss of the infection using regression models of generalized estimating equations. H. pylori status was determined by ¹³C‐urea breath test. Results: Data from 37.7% (133/353) of the children were available. No difference between the characteristics of the included and nonincluded children was observed. The prevalence of infection increased from 53.4 to 64.7%. Thirty‐nine children (29.3%) remained noninfected, 47.4% remained infected, 17.3% became infected, and 6.0% lost the infection. Factors associated with to remain infected compared with to remain noninfected included the age, increased number of children in the household, and the use of well water instead of municipal water. The acquisition of the infection was associated with the male gender. Conclusion: Factors linked to remain and to gain H. pylori infection in a poor region were increased number of children in the household and the male gender. Also, the acquisition rates were higher than the loss rates, which lead to an increase in the infection prevalence with age.     

Younger siblings play a major role in Helicobacter pylori transmission among children from a low-income community in the Northeast of Brazil

Background and Aims: To further evaluate intrafamilial transmission of H. pylori infection during childhood, we investigated the prevalence of H. pylori in family members from a poor H. pylori high‐prevalence urban community in the Northeast of Brazil. Methods: H. pylori infection was investigated in 570 members of 128 households, by ¹³C‐urea breath test in children and by ELISA in mothers and other adult relatives. Results: The overall prevalence of H. pylori infection (376/570) increased with age (p < .001) and ranged from 28.9%, in children aged 6 months to 5 years, to 82% in adults over 40 years. An H. pylori positive mother and the number of infected siblings are independent risk factors for childhood H. pylori infection (OR = 2.2, 95% CI = 1.0–4.6 and OR = 4.3, 95% CI = 2.3–8.1, respectively) The number of siblings, number of younger siblings, and number of infected younger siblings were also associated with the infection in the univariate analysis. The number of infected younger siblings remained independently associated with the infection (p = .000), even after controlling for all the above cited variables, in addition to the H. pylori status of siblings and mothers, age, number of people per room, and number of children in the household. Conclusion: The transmission of H. pylori occurs from infected mothers to their offspring and among siblings, notably from younger siblings to the older ones.     

Decreasing trend of Helicobacter pylori infection in children with gastrointestinal symptoms from Buenos Aires, Argentina

Background: Helicobacter pylori infection is declining in developed and developing countries. The aim of this study was to retrospectively evaluate over an 8‐year period the rate of H. pylori infection in children with gastrointestinal symptoms from Buenos Aires, Argentina. Materials and Methods: We reviewed the records of children referred from 2002 to 2009 to the gastroenterology unit of the Children Hospital “Superiora Sor Maria Ludovica” for evaluation of upper gastrointestinal signs and symptoms in which the ¹³C‐urea breath test was performed to diagnose H. pylori infection and a sociodemographic questionnaire was obtained. Results: Records of a total of 1030 children and adolescents with a mean age of 9.99 years were included in the analysis. We found an H. pylori prevalence of 41.2% (95% CI, 36.9–46.0%) for the triennium 2002–2004, dropping to 26.0% (95% CI, 20.7–31.8%) in the triennium 2007–2009. Conclusion: Our results showed a significant decrease in H. pylori infection rates from children referred for upper gastrointestinal symptoms evaluation from 2002 to 2009, following the H. pylori epidemiologic trend reported in other countries.     

Prevalence and incidence of Helicobacter pylori Infection in a healthy pediatric population in the Lisbon area

Background: Helicobacter pylori is mainly acquired in childhood. Although adult studies reported a high prevalence of H. pylori infection in Portugal, the actual rate in children remains unknown. This study aimed to determine the prevalence and the incidence of H. pylori infection in an asymptomatic pediatric population of the Lisbon area and to correlate prevalence with sociodemographic determinants. Materials and Methods: Helicobacter pylori infection was determined by stool antigen test in 844 asymptomatic children (age 0–15 years; 49.4% boys). For the incidence study, H. pylori‐negative children in the prevalence study were followed‐up every 6 months over a 3‐year period. Results: The global prevalence of H. pylori infection was 31.6%, increasing with age (19.9, 37.0 and 51.5%, in age groups 0–5, 6–10, and 11–15, respectively), but was similar among genders (34.5% in boys and 28.4% in girls). Older age and attendance of nursery/kindergarten during preschool constituted independent risk factors. The overall estimated incidence was 11.6 per 100 child‐years (CY). Although 47.5% of children acquired H. pylori infection before 5 years of age, the mean age of acquisition was 6.3. The incidence of infection was similar among the three age groups (11.5, 13.0, and 10.5 per 100 CY, in age groups 0–5, 6–10, and 11–15, respectively). Conclusions: The prevalence of H. pylori infection in the Portuguese pediatric population is still high. Although this study confirmed that the highest acquisition rate occurs at young age, it showed that in high‐prevalence populations, older children can also acquire H. pylori infection at a rate similar to that of young children.     

The impact of Helicobacter pylori on atopic disorders in childhood

Background: The prevalence of Helicobacter pylori in Western populations has steadily decreased. This has been suggested as one of the factors involved in the recent increase of asthma and allergy. Some studies have reported a negative association between H. pylori and asthma and allergy, but data are inconsistent and there are a few studies in children. Aim: We investigated whether the prevalence of H. pylori was associated with asthma symptoms, allergic rhinitis, and atopic dermatitis in childhood. Methods: We determined IgG anti‐H. pylori and CagA antibodies in serum of Dutch children, who took part in the PIAMA birth cohort study. Serum was collected from 545 children, aged 7–9 years (Dutch ethnicity 91.5%). Symptoms of asthma and atopy were assessed by yearly questionnaires. Chi‐square tests and logistic regression were used. Results: We found 9%H. pylori and 0.9% CagA seropositivity. Twelve (5.9%) children with reported wheezing ever were H. pylori positive, compared to 37 (10.9%) of the non‐wheezers (p = .05). No significant differences in H. pylori prevalence were found between children with or without allergic rhinitis (8.5% vs 9.5%), atopic dermatitis (8.7% vs 9.2%), and physician‐diagnosed asthma (7.1% vs 9.4%). Multivariate analysis showed no significant associations between H. pylori seropositivity and wheezing (OR 0.52; 95% CI 0.25–1.06), allergic rhinitis (OR 0.96; 95% CI 0.51–1.81), atopic dermatitis (OR 1.05; 95% CI 0.56–1.98) or physician‐diagnosed asthma (OR 0.87; 95% CI 0.37–2.08). Conclusion: We found a borderline significantly lower H. pylori seropositivity in children with wheezing compared to non‐wheezers, but no association between H. pylori serum‐antibody status and allergic rhinitis, atopic dermatitis, or asthma.     

Asymptomatic Helicobacter pylori infection and iron deficiency are not associated with decreased growth among Alaska Native children aged 7-11 years

Introduction: Alaska Native children have high Helicobacter pylori infection and iron deficiency prevalences, and their average height‐for‐age is lower than US reference populations. During a clinical trial to determine the impact of H. pylori treatment on iron deficiency, we evaluated the effects of H. pylori infection and treatment on growth. Materials and Methods: We measured height and weight for children aged 7–11 years in western Alaska using village‐based measuring devices. H. pylori infection was determined by urea breath test and iron deficiency using serum ferritin. Children with H. pylori infection and iron deficiency entered the treatment phase and received iron alone or iron plus triple therapy for H. pylori. Follow‐up evaluations occurred at 2, 8, and 14 months. We evaluated the association between baseline H. pylori infection and growth; among children in the treatment phase, we also assessed the effect of H. pylori resolution on growth. Results: At baseline, 566 (87.1%) of 650 children were infected with H. pylori. Neither height and weight, nor body mass index differed by H. pylori infection status. Of 189 children in the treatment phase, 20 (10.6%) were uninfected at all three follow‐up periods, and 54 (28.6%) were uninfected for one or two periods. Compared with continuously infected children, children in these two groups had little evidence of improvements in any of the measured growth outcomes. Conclusions: H. pylori infection is not related to growth among Alaska Native children aged 7–11 years. Growth deficiency should not be considered an indication for H. pylori therapy.     

Age at acquisition of Helicobacter pylori infection: comparison of two areas with contrasting risk of gastric cancer

Background. Helicobacter pylori infection is usually acquired during childhood and is a known risk factor for the development of gastric malignancies in adulthood. It has been reported that early age at first infection may determine a neoplastic outcome in adults. The purpose of this study was to determine the prevalence of Helicobacter pylori infection in children residing in areas with high (Pasto) and low risk (Tumaco) of gastric cancer in Colombia to evaluate whether differences in the age of acquisition of H. pylori infection were present in the two populations. Materials and Methods. The study sample was based on a census taken in 1999. Using the ¹³C‐urea breath test, we compared the prevalence of H. pylori infection among children aged 1–6 years. Results. Among 345 children in Pasto, 206 (59.7%) were H. pylori‐positive, compared with 188 (58.6%) among 321 children in Tumaco. The two populations share a common pattern of very early age at infection and marked increase in prevalence during the first 4 years of life. No differences in any one year were observed when comparing the two groups. Conclusions. The prevalence of infection was similarly high and increased with age in both populations. In these populations the age of acquisition of H. pylori after 1 year of age does not appear to be a primary factor responsible for the differences in the rates of gastric cancer incidence in adults. Previous findings in adults showed lower prevalence of the most virulent genotypes in Tumaco compared to Pasto, and bacterial virulence may play a key role in determining cancer outcome.     

Is the Association Between Helicobacter pylori Infection and Anemia Age Dependent?

Background: The relationship between H. pylori infection and anemia in childhood is still unclear. The aim of the study was to examine the association between H. pylori infection and anemia or iron deficiency in school‐age children and in infants. Materials and Methods: Six‐ to 9‐ year‐old Israeli Arab children (N = 202) and infants (N = 197) were examined for hemoglobin and ferritin levels. ELISA was used to detect H. pylori antigens in stool specimens collected from the participants. Household characteristics were obtained through personal interviews with the mothers. Results: The prevalence of anemia was 15.5 versus 5.5% in H. pylori‐positive and ‐negative school‐age children, respectively and 34.5 versus 29.8% in H. pylori‐positive and ‐negative infants, respectively. The Mantel–Haenszel age‐adjusted prevalence ratio (PR) and 95% confidence intervals (CIs) were 1.6 (95%CI 1.0, 2.6). In multivariate analysis controlling for socioeconomic variables, H. pylori infection was associated with 2.8 higher prevalence of anemia only in school‐age children: adjusted PR 2.8 (95% CI 0.9, 9.3). The adjusted mean difference in hemoglobin levels between H. pylori infected school‐age children and uninfected ones was ?0.372 gr/dL (95% CI ?0.704, ?0.039) (p = .04). The respective mean ferritin difference was ?6.74 μg/L (95% CI ?13.38, ?.011) (p = .04). Such differences were not found in infants. Conclusions: H. pylori infection is associated with higher prevalence of anemia in school‐age children independently of socioeconomic variables. Such association was not observed in infants. These findings are of clinical and public health importance.     

13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a systematic review and meta-analysis

Background: The ¹³C‐urea breath test (¹³C‐UBT) is a safe, noninvasive and reliable method for diagnosing H. pylori infection in adults. However, the test has shown variable accuracy in the pediatric population, especially in young children. We aimed to carry out a systematic review and meta‐analysis to evaluate the performance of the ¹³C‐UBT diagnostic test for H. pylori infection in children. Methods: We conducted a systematic review of the PubMed, Embase and Liliacs databases including studies from January 1998 to May 2009. Selection criteria included studies with at least 30 children and reporting the comparison of ¹³C‐UBT against a gold standard for H. pylori diagnosis. Thirty‐one articles and 135 studies were included for analysis. Children were stratified in subgroups of <6 and ≥6 years of age, and we considered variables such as type of meal, cutoff value, tracer dose, and delta time for the analysis. Discussion: The ¹³C‐UBT performance meta‐analyses showed 1, good accuracy in all ages combined (sensitivity 95.9%, specificity 95.7%, LR+ 17.4, LR? 0.06, diagnostic odds ratio (DOR) 424.9), 2, high accuracy in children >6 years (sensitivity 96.6%, specificity 97.7%, LR+ 42.6, LR? 0.04, DOR 1042.7), 3, greater variability in accuracy estimates and on average a few percentage points lower, particularly specificity, in children ≤6 years (sensitivity 95%, specificity 93.5%, LR+ 11.7, LR? 0.12, DOR 224.8). Therefore, the meta‐analysis shows that the ¹³C‐UBT test is less accurate for the diagnosis of H. pylori infection in young children, but adjusting cutoff value, pretest meal, and urea dose, this accuracy can be improved.     

A population-based survey on gastrointestinal tract symptoms and Helicobacter pylori infection in children and adolescents

Background. Helicobacter pylori infection is a frequent infection mainly acquired in childhood. Even if the infection is almost invariably associated with mild to severe gastro‐duodenal lesions, no specific clinical picture has been identified. The aim of this study was to evaluate the presence of dyspeptic symptoms and their relationship with the presence of H. pylori infection in the first two decades of life. Materials and Methods. A school‐population sample size of 808 subjects from 6‐ to 19‐year‐olds was investigated for the presence of gastrointestinal tract symptoms and evaluated by a ¹³C‐urea breath test for H. pylori infection. The relationship between clinical findings and H. pylori infection was evaluated by χ² statistic or Fisher's exact test, as appropriate. Results. Symptoms of dyspepsia were identified in 45% of subjects, while the picture of ulcer‐like and dysmotility‐like forms were present in 3–4%. H. pylori infection was demonstrated in 95 (11.8%) subjects, 49.5% of them without symptoms. Severe epigastric pain and ulcer‐like dyspepsia were significantly associated with H. pylori infection, while recurrent abdominal pain or dysmotility‐like dyspepsia were not. Conclusions. Dyspeptic symptoms are frequent in children, and its association with H. pylori infection is more evident than with recurrent abdominal pain. The age at which the infection is acquired seems to be under 6 years of age.     

Eradication of Helicobacter pylori infection improves blood pressure values in patients affected by hypertension

Background. Arterial hypertension is a risk factor for atherosclerosis of whose pathogenesis is unknown. Growing evidence underscores the causative role of endothelial dysfunction. A possible association between Helicobacter pylori infection and cardiovascular and autoimmune disorders has been found. The release of cytotoxic substances either of bacterial origin or produced by the host may represent mediators of these systemic sequelae. The aim of our study was to determine the prevalence of H. pylori infection in hypertensive patients and the effects of H. pylori eradication on blood pressure and on digestive symptoms. Materials and Methods. Seventy‐two hypertensive patients (34 male and 38 female; mean age 53 ± 12 years) and 70 normotensive controls (35 male and 35 female; mean age 52 ± 10 years) were enrolled. All patients were subjected to a first ambulatory blood pressure monitoring (ABPM) at enrollment, a ¹³C urea breath test and a test for IgG‐CagA antibodies, and completed the validated dyspepsia questionnaire. H. pylori‐positive patients were treated with triple therapy (amoxicillin, clarithromycin and ranitidine bismute citrate) for 7 days. Control of eradication was assessed by ¹³C urea breath test, and all patients underwent a second ABPM 6 months after enrollment. Results. H. pylori infection was 55% in hypertensive patients, with 90% CagA positivity, and 50% in controls, with 60% CagA positivity. At the first ABPM, blood pressure values were similar in H. pylori‐positive and ‐negative individuals; positive patients showed a significant increase in pyrosis and epigastric pain compared to negative patients. H. pylori was eradicated in 80% of patients and in 85% of controls. At the second ABPM, we found a statistically significant decrease in 24‐hour mean blood pressure values when compared to the first ABPM only in the eradicated hypertensive group. Conclusions. Our study demonstrated a significant decrease in blood pressure values, in particular in diastolic blood pressure values, after H. pylori eradication in hypertensive patients. A high prevalence of CagA positivity was found. The association between cardiovascular disease and H. pylori infection seems pronounced only in CagA‐positive patients. The possible links between hypertensive disease and H. pylori infection may involve the activation of the cytokine cascade with the release of vasoactive substances from the primary site of infection, or molecular mimicry between the CagA antigens of H. pylori and some peptides expressed by endothelial cells and smooth muscle cells.     

Helicobacter pylori infection in asymptomatic children: comparison of diagnostic tests

Background. Childhood is known to be a major risk period for acquiring Helicobacter pylori infection. Studies of the epidemiology of H. pylori infection depend on the validity of the diagnostic tools used to detect the infection in the pediatric setting. This study aims to conduct a combination of diagnostic tests on the same children, evaluate the sensitivity and the specificity of IgG antibody testing compared with the ¹³C‐urea breath test, and examine the variability in the prevalence of H. pylori infection in asymptomatic children based on the use of different diagnostic tests. Methods. ¹³C‐urea breath test (¹³C‐UBT), whole blood FlexSure (systemic antibodies), and OraSure (salivary antibodies) tests were conducted on 287 asymptomatic children (151 boys, 136 girls; ages 2–18 years). The three tests were conducted on each child during the same day. The prevalence was calculated using each test independently. Results. H. pylori infection was detected in 32%, 22%, or 18% of the studied children, based on UBT, OraSure, or FlexSure, respectively. A total of 103 children tested positive for any one test (92 on UBT, 8 on FlexSure, 3 on OraSure), giving a prevalence of 35% based on the “parallel” method. Only 39 children tested positive in all three tests, giving a prevalence of 14% based on the “serial” method. Using the UBT as the gold standard, the sensitivity of FlexSure and OraSure were 48% and 65%, respectively, and the specificity of both tests was greater than 95%. When we applied the parallel method, the sensitivity and specificity of the combined antibody tests (FlexSure+OraSure) compared to the UBT were 71% and 95%, respectively. Conclusions. Among asymptomatic children, there is a wide variation in the prevalence of H. pylori infection based on the diagnostic test used. The study shows that antibody assays are less suitable than the UBT. However, under certain conditions, the IgG assays (combined systemic, salivary, or both) are less expensive alternative tools to the UBT for epidemiological studies in children.     

The association of intestinal parasitosis and H. pylori infection in children and adults from a Mexican community with high prevalence of parasitosis

Background. ABSTExperimental evidences have suggested that a Th1 response is unable to eliminate H. pylori colonization; whereas a Th2 response, like the one induced by vaccination, reduces H. pylori infection in animal models. Some parasitic infections induce a polarized Th2 response, which theoretically would favor a reduced H. pylori prevalence. The aim of this work was to study the possible association between parasitic infections and H. pylori prevalence. Materials and Methods. The study population included 120 children and 188 adults from a low socioeconomic level village. H. pylori prevalence was determined in serum by ELISA; parasitic infections were identified in feces by microscopic examination; and total serum IgE levels, as an indirect indicator of some parasitic infections, were determined by ELISA. Results. In children, H. pylori prevalence was no different between those with and without intestinal parasitic infection. By contrast, adults with intestinal parasitic infection had a significantly lower H. pylori prevalence than adults without parasites (62.6% compared with 80.4%; p = 0.006, OR 2.45). Also in adults, but not in children, total IgE levels were significantly higher in those without H. pylori infection than in those with H. pylori infection (p < 0.001). Conclusions. Intestinal parasitic infections and serum IgE levels showed an age‐dependent association with H. pylori prevalence. In adults, but not in children, intestinal parasitic infections and increased IgE levels where associated with a reduced H. pylori prevalence.     

The effect of Helicobacter pylori and economic status on growth parameters and leptin, ghrelin, and insulin-like growth factor (IGF)-I concentrations in children

Background: It was suggested that gastric colonization with Helicobacter pylori (H. pylori) was associated with suboptimal nutrition and growth in childhood. Furthermore, several studies indicated a relationship between H. pylori colonization and alterations in the circulating levels of growth‐related molecules (GRM). Accordingly, in this study, we investigate the effect of H. pylori infection on GRMs and on the growth of healthy school children, taking into consideration the effect of their economic status (ES) and anthropometric indices of their parents. Methods: To acquire sociodemographic and anthropometric nutritional parameters and to detect H. pylori‐specific serum IgG antibodies and growth‐related molecules, we evaluated a total of 473 children attending four different primary and secondary schools in Istanbul. Subsequently, we assessed the effect of H. pylori on growth‐related parameters (weight for age SDS, height for age SDS, BMI SDS, TSF, and waist‐to‐hip ratio) and on GRMs (leptin, ghrelin, and insulin‐like growth factor‐1 (IGF‐1)), controlling for age, gender, family income, household crowding (HC), breastfeeding, maternal and paternal BMI SDS, and midparental height SDS with complex statistical models. Results: Of the 473 children (275 F/198 M, age 6–15 years; mean: 10.3 ± 0.1 years), 161 (34%) were H. pylori‐positive. The prevalence of H. pylori was significantly higher in lower economic status (ES) groups, in children living in crowded houses, and in older age groups. Using simple statistical models, we did not find any significant associations between H. pylori infection and the growth parameters. However, in complex models for height for age SDS and for weight for age SDS, there was a significant interaction between H. pylori infection status and ES. Whereas in H. pylori‐positive subjects, mid‐income family children were both taller and heavier than the low‐income group, there was no such an association in H. pylori‐negative subjects. Among biochemical parameters, only ghrelin levels were associated with H. pylori infection in all models. Leptin levels were associated with HC in girls, whereas none of the parameters was significantly associated with leptin levels in boys. For IGF‐1 levels, for boys, age and maternal BMI, and for girls, age and HC were significantly associated with IGF‐1 levels. Conclusion: We suggest that H. pylori may impair growth significantly only in susceptible children where unfavorable socioeconomic conditions facilitate its action, probably through mechanisms, at least in part, involving growth‐related molecules.     

Probiotics-containing yogurts suppress Helicobacter pylori load and modify immune response and intestinal microbiota in the Helicobacter pylori-infected children

Background: The benefits of probiotics to the pediatric Helicobacter pylori infection remain uncertain. We tested whether the H. pylori‐infected children have an altered gut microflora, and whether probiotics‐containing yogurt can restore such change and improve their H. pylori‐related immune cascades. Methods: We prospectively included 38 children with H. pylori infection confirmed by a positive ¹³C‐urea breath test (UBT) and 38 age‐ and sex‐matched noninfected controls. All of them have provided the serum and stool samples before and after 4‐week ingestion of probiotics‐containing yogurt. The serum samples were tested for the TNF‐α, IL‐10, IL‐6, immunoglobulin (Ig) A, G, E, pepsinogens I and II levels. The stool samples were tested for the colony counts of Bifidobacterium spp. and Escherichia coli. The follow‐up UBT indirectly assessed the H. pylori loads after yogurt usage. Results: The H. pylori‐infected children had lower fecal Bifidobacterium spp. count (p = .009), Bifidobacterium spp./E. coli ratio (p = .04), serum IgA titer (p = .04), and pepsinogens I/II ratio (p < .001) than in controls. In the H. pylori‐infected children, 4‐week yogurt ingestion reduced the IL‐6 level (p < .01) and H. pylori loads (p = .046), but elevated the serum IgA and pepsinogen II levels (p < .001). Moreover, yogurt ingestion can improve the childhood fecal Bifidobacterium spp./E. coli ratio (p = .03). Conclusions: The H. pylori‐infected children have a lower Bifidobacterium microflora in gut. The probiotics‐containing yogurt can offer benefits to restore Bifidobacterium spp./E. coli ratio in children and suppress the H. pylori load with increment of serum IgA but with reduction in IL‐6 in H. pylori‐infected children.     

Non-invasive genotyping of Helicobacter pylori cagA, vacA, and hopQ from asymptomatic children

Background: Helicobacter pylori infection is usually acquired in childhood, but little is known about its natural history in asymptomatic children, primarily due to the paucity of non‐invasive diagnostic methods. H. pylori strains harboring cagA and specific alleles of hopQ and vacA are associated with increased risk for gastric cancer. Many studies of H. pylori virulence markers in children have the bias that symptomatic subjects are selected for endoscopy, and these children may harbor the most virulent strains. Our aim is to genotype cagA, hopQ, and vacA alleles in stool DNA samples of healthy Colombian children residing in an area with high incidence of gastric cancer, to avoid selection bias resulting from endoscopy. Methods: H. pylori status of 86 asymptomatic children was assessed by ¹³C‐urea breath test (UBT) and PCR. H. pylori 16S rRNA, cagA, hopQ, and vacA genes were amplified from stool DNA samples and sequenced. Results: UBT was positive in 69 (80.2%) of 86 children; in stool DNA analysis, 78.3% were positive by 16S rRNA PCR. cagA, vacA, and hopQ were detected in 66.1%, 84.6%, and 72.3% of stool DNA samples from 16S rRNA‐positive children. Of the children’s DNA samples, which revealed vacA and hopQ alleles, 91.7% showed vacA s1 and 73.7% showed type I hopQ. Type I hopQ alleles were associated with cagA positivity and vacA s1 genotypes (p < 0.0001). Conclusions: Using stool DNA samples, virulence markers of H. pylori were successfully genotyped in a high percentage of the asymptomatic infected children, revealing a high prevalence of genotypes associated with virulence. Type I hopQ alleles were associated with the presence of cagA and the vacA s1 genotype.     

Role of 13C-urea breath test in experimental model of Helicobacter pylori infection in mice

Background: Animal models have been widely used to study Helicobacter pylori infection. Evaluation of H. pylori infection status following experimental inoculation of mice usually requires euthanasia. The ¹³C‐urea breath test (¹³C‐UBT) is both sensitive and specific for detection of H. pylori in humans. Thus, it would be very useful to have such a test with the same accuracy for the follow‐up of this infection in animal models of gastric infection. Accordingly, the purpose of this study was to develop and evaluate a ¹³C‐UBT method for following the course of H. pylori infection in a mouse model. Material and Methods: A total of 50 female C57BL/6 mice were gavaged three times with either 10⁸ colony‐forming units of H. pylori (n = 29) or saline solution only (n = 21). After 2 months of infection, mice were fasted for 14 hours and ¹³C‐UBT was performed using 300 μg of ¹³C‐urea. The mice were killed, and the stomach was removed and processed for immunohistochemistry and PCR. Results: The optimal time for breath sample collection in mice was found to be 15 minutes. The ¹³C‐UBT cutoff was set at 3.0‰δPDB. Using PCR as the gold standard, the sensitivity of ¹³C‐UBT and immunohistochemistry was 96.6 and 72.4%, respectively, while the specificity was 85.7 and 95.2%, respectively. Conclusions: ¹³C‐UBT was shown to be a reliable method for the detection of H. pylori infection in C57BL/6 mice and was even more accurate than immunohistochemistry. The use of ¹³C‐UBT in the mouse model of H. pylori infection can be very useful to detect the bacterium without the need to kill the animals in long‐term time course studies.     

Peptic ulcers and erosions are common in Israeli children undergoing upper endoscopy

Background: Peptic ulcers and erosions (PU&E) are thought to be uncommon in children. Patients with early exposure to Helicobacter pylori may be at a higher risk for early onset PU&E. Children in Israel have a high prevalence and early acquisition of Helicobacter pylori (H. pylori) and have easy access to pediatric gastroenterologists and endoscopy. Our aim was to describe the prevalence and characteristics of PU&E in this population referred by Pediatric Gastroenterologists for an upper endoscopy. Methods: We conducted a retrospective study over the years January 2003–May 2006. Over these years we had information on 751 diagnostic upper endoscopies. PU&E was regarded as erosive gastritis/duodenitis or ulcer in either the stomach or duodenum. H. pylori status was assessed using rapid urease test and gastric biopsies. Results: PU&E was detected in 169 (22.5%) patients (ulcers 51 (6.8%), erosions 118 (15.7%)). One hundred twenty‐four had gastric PU&E and 58 had duodenal PU&E. H. pylori was positive in 112 (66.3%). H. pylori‐associated PU&E becomes common after age 10 years, with gastric PU&E presenting much earlier than duodenal disease. Most of the H. pylori‐negative PU&E were idiopathic and improved symptomatically on PPI treatment. Interestingly, 43% of patients with PU&E in our cohort were either immigrants from the former Soviet Union or of Israeli Arab origin. Conclusions: PU&E appears to be common in this selected population with a relatively high incidence of gastric PU&E. H. pylori associated PU&E becomes common after age 10 years with gastric PU&E presenting much earlier than duodenal disease. Non H. pylori PU&E in children comprises approximately a third of all PU&E, are mostly idiopathic and appear earlier than H. pylori associated PU&E.     

Low prevalence of Helicobacter pylori-negative gastric cancer among Japanese

Background and Aims: The true prevalence of Helicobacter pylori‐negative gastric cancer (HpNGC) is unknown. We attempt to clarify the prevalence and clinicopathologic features of HpNGC in Japanese. Methods: Helicobacter pylori infection was detected by antibody titer and microscopic observation. In addition, we confirmed the lack of endoscopic atrophy and histologic gastritis. In these cases, we added urea breath test or rapid urease test to confirm the absence of H. pylori. The mucus phenotype of gastric cancer tissue was also evaluated by immunohistochemistry. Results: We screened 3161 gastric cancer cases from 1996 to 2010, and 21 cases were regarded as H. pylori negative. Clinically, patients with HpNGC were younger than patients with H. pylori‐positive gastric cancer (controls), and revealed a lack of male dominancy. Histologically, diffuse type was frequently found. All patients examined were pepsinogen negative. Among HpNGC cases with endoscopic resection, the depressed macroscopic appearance was dominant. The prevalence of HpNGC was calculated as 0.66% (95% confidence interval = 0.41–1.01). The mucus phenotype of HpNGC was similar to that of the controls. Conclusion: The prevalence of HpNGC is very low and its pathological characteristics are different from common gastric cancer.