History of antibiotic treatment and prevalence of H. pylori infection among children: results of a population-based study

Adapted first-line treatment of Helicobacter pylori infection in Algerian children

BACKGROUND

Helicobacter pylori (H. pylori) infection is acquired in early life and continues to have a high prevalence, especially in developing countries. Growing antibiotic-resistant strains necessitate adapted treatments. This study aimed to compare the efficacy, side effects, and influence of resistance of H. pylori strains between two different treatments.

METHODS

This prospective, randomized blind study enrolled 112 symptomatic children infected with H. pylori (66 girls, mean age 11.1 years). Treatments, allocated randomly irrespective of the susceptibility of the strains, were either the standard omeprazole-amoxicillin-clarithromycin combination for 7 days (OAC7; group A) or omeprazole-amoxicillin with a higher dose of metronidazole (40 instead of 20 mg/kg/d) for 10 days (OAM10; group B).

RESULTS

Before treatment, the resistance rates of H. pylori strains to metronidazole or clarithromycin were 37% and 13%, respectively, with 7% resistant to both antibiotics and neither to amoxicillin. Eradication rates obtained with OAM10 (80% by intention-to-treat [ITT] and 88% by per protocol [PP] analysis) were higher than with OAC7 (68% in ITT and 71% PP) and the differences (12% in ITT and 17% PP) were statistically significant (P=0.03). Successful treatments with OAM10 were obtained in metronidazole resistant strains and were more effective in children aged >10 years (P=0.02 by ITT and P=0.04 by PP). Only light or moderate side effects, mainly digestive, were observed.

CONCLUSION

Because of its therapeutic efficacy, good tolerance and lower cost the OAM10 can be considered as an appropriate first-line therapeutic scheme in Algeria.

Prevalência de infecção por Helicobacter pylori em uma comunidade indígena em São Paulo e fatores associados: estudo transversalPrevalence of Helicobacter pylori infection in an indigenous community in São Paulo and associated factors: cross-sectional study

CONTEXT AND OBJECTIVE:

The prevalence of Helicobacter pylori infection is unevenly distributed among different populations. The aim here was to evaluate the factors associated with Helicobacter pylori infection among children up to five years of age living in a high-risk community.

DESIGN AND SETTING:

Cross-sectional study in an indigenous community of Guarani Mbya ethnicity, Tekoa Ytu and Tekoa Pyau villages, Jaraguá district, city of São Paulo (SP), Brazil.

METHODS:

74 children aged 0.4 to 4.9 years (mean 2.9 ± 1.3 years; median 3.1), and 145 family members (86 siblings, 43 mothers and 16 fathers) were evaluated for Helicobacter pylori infection using the validated 13C-urea breath test. Clinical and demographic data were collected.

RESULTS:

The prevalence was 8.3% among children aged 1-2 years and reached 64.3% among those aged 4-5 years (P = 0.018; overall 31.1%). The prevalence was 76.7% among siblings and 89.8% among parents. There was a negative association with previous use of antibiotics in multivariate analysis adjusted for age (odds ratio, OR: 0.07; 95% confidence interval, CI: 0.01 to 0.66; P = 0.02). The prevalence was higher among males (OR: 1.55), and was associated with maternal infection (OR: 1.81), infection of both parents (OR: 1.5), vomiting (OR: 1.28), intestinal parasitosis (OR: 2.25), previous hospitalization (OR: 0.69) and breastfeeding (OR: 1.87).

CONCLUSIONS:

The prevalence was high among subjects older than three years of age, thus suggesting that the incidence of infection was higher over the first three years of life. Previous use of antibiotics was inversely associated with current Helicobacter pylori infection.

Incidence, age of acquisition and risk factors of Helicobacter pylori infection among Israeli Arab infants

We examined the age of acquisition of Helicobacter pylori infection in a prospective study that was conducted among 231 Israeli Arab children. Helicobacter pylori was identified in stool specimens collected at ages 2, 4, 6, 8, 12 and 18 months, using a monoclonal stool antigen immunoassay. Information on household characteristics, breastfeeding, antibiotic use and hygiene practices was obtained. The incidence of H. pylori infection was 33.3%. The estimated mean age of H. pylori infection acquisition was 14 months. The determinants of H. pylori infection were living in a low socioeconomic status (SES) village: OR 9.60 (95% CI 2.91-31.68, p < 0.001); low paternal education: OR 3.35 (95% CI 1.21-9.29, p = 0.02); and boiling feeding bottles and nipples at low frequency: OR 7.12 (95% CI 1.82-27.86, p = 0.005). In conclusion, H. pylori infection is acquired at a higher rate in low SES settings. Parental education and hygiene play an important role in H. pylori acquisition in infancy.

Antibiotics taken for other illnesses and spontaneous clearance of Helicobacter pylori infection in children

PURPOSE

Factors that determine persistence of untreated Helicobacter pylori (H. pylori) infection in childhood are not well understood. We estimated risk differences for the effect of incidental antibiotic exposure on the probability of a detected clearance at the next test after an initial detected H. pylori infection.

METHODS

The Pasitos Cohort Study (1998-2005) investigated predictors of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico. Children were screened for infection at 6-month target intervals from 6 to 84 months of age, using the 13C-urea breath test corrected for body-size-dependent variation in CO2 production. Exposure was defined as courses of any systemic antibiotic (systemic) or those with anti-H. pylori action (HP-effective) reported for the interval between initial detected infection and next test. Binomial regression models included country of residence, mother's education, adequacy of prenatal care, age at infection, and interval between tests.

RESULTS

Of 205 children with a test result and antibiotic data following a detected infection, the number of children who took > or =1 course in the interval between tests was 74 for systemic and 33 for HP-effective. The proportion testing negative at the next test was 66% for 0 courses, 72% for > or =1 systemic course, and 79% for > or =1 HP-effective course. Adjusted risk differences (95%CI) for apparent clearance, comparing > or =1 to 0 courses were 10% (1-20%) for systemic and 11% (0-21%) for HP-effective.

CONCLUSIONS

Incidental antibiotic exposure appears to influence the duration of childhood H. pylori infection but seems to explain only a small portion of spontaneous clearance.

Epidemiology of Helicobacter pylori infection in asymptomatic children: a prospective population-based study from the Czech Republic. Application of a monoclonal-based antigen-in-stool enzyme immunoassay

BACKGROUND

Acquisition of Helicobacter pylori occurs mainly in childhood and is significantly influenced by geographical variations. The aim of this study is to evaluate the prevalence of H. pylori infection in a population-based sample of asymptomatic children in the Czech Republic. Furthermore, this study aims to identify potential risk factors associated with this infection.

MATERIALS AND METHODS

A prospective, cross-sectional, population-based study was undertaken in 1545 asymptomatic Czech children (aged 0-15 years; male 49.3%). Active H. pylori infection was diagnosed by monoclonal antibody-based antigen-in-stool enzyme immunoassay. Socio-demographic details of each subject were analyzed using a self-administered standardized questionnaire. Multiple regression analysis was performed.

RESULTS

Overall, 7.1% of asymptomatic children were diagnosed with H. pylori infection. Of the infected children, 5.8% lived in the general population. A positive association was found with increasing age, although not with gender. Independent risk factors associated with H. pylori infection in our pediatric population were: the number of children in a household (odds ratio [OR] 4.26; confidence interval [CI] 1.91-9.80); lack of formal education of fathers (OR 0.23; CI 0.18-0.64) and institutionalized children (OR 6.33; CI 2.25-26.50).

CONCLUSIONS

This study of a large cohort of children demonstrated that, independent of gender, H. pylori infection in the Czech Republic is among the lowest reported in Europe. Socioeconomically disadvantaged children, unfortunately, are still at risk of harboring this potentially preventable infection in this low-prevalence region.

Utility of diagnostic tests for detection of Helicobacter pylori in children in northeastern Mexico

BACKGROUND

The presence of Helicobacter pylori in pediatric population has been associated with recurrent abdominal pain (RAP), although this association is unclear. One of the major problems in studying the role of H. pylori in RAP is that methods used to detect the bacteria in children have poor sensitivity and specificity. The aims of the present study were to determine the prevalence of H. pylori in pediatric patients with RAP in northeastern Mexico and to assess the diagnostic utility of invasive tests and serology in this population.

METHODS

A total of 40 patients (mean age, 7.9 years; range 2-16 years; F: M, 0.81), who underwent an endoscopy procedure for RAP, were studied. The presence of H. pylori was assessed using invasive diagnostic tests (culture, rapid urease test, polymerase chain reaction and histology) and one non-invasive test: determination of IgG antibodies. The prevalence of H. pylori in the present group and the diagnostic utility for each test were evaluated.

RESULTS

The prevalence of H. pylori in the present pediatric group with RAP was 12.5-42.5% depending on the criteria of positivity used. The non-invasive methods (serology) had acceptable values in sensitivity and specificity in comparison with invasive tests.

CONCLUSIONS

This is the first report on prevalence of H. pylori in pediatric patients with RAP from the northeastern region of Mexico. The prevalence of H. pylori was low compared with the adult population in the same geographic region. Serology had the best diagnostic utility.

Helicobacter pylori occurrence and transmission: a family affair?

About half of the world's population is estimated to be infected with Helicobacter pylori, a gastric bacterium that contributes to the development of peptic ulcer disease and gastric cancer. H. pylori is more prevalent in low-income areas of the world and social and economic development decreases the prevalence as reflected in comparisons both within and between countries. The infection is typically acquired in early childhood and once established commonly persists throughout life unless treated. Person-to-person transmission within the family appears to be the predominant mode of transmission, particularly from mothers to children and among siblings, indicating that intimate contact is important. The route of transmission is uncertain, but the gastro-oral, oral-oral and faecal-oral routes are likely possibilities. Hence, gastroenteritis may facilitate dissemination of the infection. The community and environment may play additional roles for H. pylori transmission in some (low-income) settings. Furthermore, host and bacterial factors may modify the probabilities of acquisition and persistence of the infection. The understanding of H. pylori occurrence and transmission is of practical importance if future study deems prevention of the infection desirable in some high-prevalence populations. The present paper reviews aspects of H. pylori occurrence and transmission with an emphasis on household factors.

Improved efficacy of 10-Day sequential treatment for Helicobacter pylori eradication in children: a randomized trial

BACKGROUND & AIMS

The currently recommended first-line eradication treatment of Helicobacter pylori in children is usually successful in about 75%. Recently, in adults, a novel 10-day sequential treatment has achieved an eradication rate of 95%. The aim of the study was to assess the H pylori eradication rate of the sequential treatment regimen compared with conventional triple therapy in children.

METHODS

Seventy-eight consecutive children with H pylori infection were randomized to receive either sequential treatment (omeprazole plus amoxicillin for 5 days, followed by omeprazole plus clarithromycin plus tinidazole for another 5 days) (n = 38; 15 boys [39.5%]; median age, 11.0 years [range, 3.3-16 years]) or triple therapy (omeprazole, amoxicillin, and metronidazole) for 1 week (n = 37; 15 boys [40.5%]; median age, 9.9 years [range, 4.3-16 years]). H pylori infection was based on 2 out of 3 positive tests results: 13C-urea breath test, rapid urease test, and histologic analysis. Eradication was assessed by 13C-urea breath test 8 weeks after therapy.

RESULTS

Seventy-four patients completed the study. H pylori eradication was achieved in 36 children receiving sequential treatment (97.3%; 95% confidence interval, 86.2-99.5) and 28 children receiving triple therapy (75.7%; 95% confidence interval, 59.8-86.7) (P < .02). Compliance with therapy was good (>95%) in all.

CONCLUSIONS

Our study shows, for the first time in children, that 10-day sequential treatment achieves a higher eradication rate than standard triple therapy, which is consistent with the results of adult studies.

High prevalence of cagA and vacA seropositivity in asymptomatic Bangladeshi children with Helicobacter pylori infection

AIM

To evaluate the prevalence of antibodies against two major markers of virulence of Helicobacter pylori--cytotoxin-associated gene A (cagA) and the vacuolating cytotoxin gene (vacA)--among children in a peri-urban community of Bangladesh, and to evaluate Western blot (WB) assay for detection of H. pylori infection diagnosed by 13C urea breath test (UBT) in such children.

METHODS

One hundred and eighty-two children aged 18-60 mo, of the peri-urban community of Dhaka, were screened for H. pylori infection using UBT, and the serum samples were analysed for antibody against cagA and vacA by Western blot.

RESULTS

The overall prevalence of H. pylori infection by 13C-urea breath test was 80%. The seroprevalence of cagA with or without vacA, vacA with and without cagA, and both cagA and vacA were 82%, 82% and 81%, respectively. Among children with a positive UBT, 95% were seropositive for both cagA and vacA, indicating that the products of these genes are frequently co-expressed in H. pylori infection in this community. The sensitivity, specificity, positive and negative predictive value of the Western blot test for H. pylori infections, compared to UBT, were 94%, 68%, 92% and 76%, respectively.

CONCLUSION

Compared to UBT, Western blot test is reliable for the detection of H. pylori infection. The high seroprevalence of cagA- and vacA-positive virulent H. pylori strains in an asymptomatic paediatric population indicate that such strains are common in this population and may cause characteristic H. pylori infection in Bangladesh.

Dynamics of Helicobacter pylori infection in early childhood in a high-risk group living in Germany: loss of infection higher than acquisition

BACKGROUND

The dynamics of Helicobacter pylori infection in early childhood are not yet well understood.

AIM

To conduct a prospective study in a population of children known to be at high risk of H. pylori infection to elucidate the incidence and loss of infection in childhood.

METHODS

Asymptomatic Turkish children [aged 1 (n = 56 children), 2 (n = 55 children) and 4 years (n = 69 children)] at baseline, on whom participating paediatricians had performed routine health screening examinations between September 1997 and October 1998, were included in the study. A follow-up was performed about 1 year later. The infection status was defined by means of an antigen-based stool assay.

RESULTS

In total, for 137 of 180 (76%) children, follow-up information was available. At baseline examination, the prevalence of infection in children with follow-up information was 27%[95% confidence interval (CI), 20-35%]. The incidence of H. pylori infection among previously uninfected children was 7% (95% CI, 3-14%) and the loss of infection among previously infected children was 35% (95% CI, 20-54%) during follow-up.

CONCLUSIONS

This prospective cohort study in a high-risk group of children living in Germany showed that H. pylori colonization may often not persist at an early age. Furthermore, the use of penicillins and macrolides may be associated with the loss of infection at an early age.

History of breastfeeding and Helicobacter pylori infection in pre-school children: results of a population-based study from Germany

BACKGROUND

Helicobacter pylori infection is predominantly acquired in early childhood. Therefore, childhood nutrition may be related to acquisition of infection. However, there are few current data from developed countries to elucidate this association. We investigated the relation between history of breastfeeding and H. pylori infection in a large population-based sample.

METHODS

Study subjects were all pre-school children in the city of Ulm, located in southern Germany and two nearby communities who were screened for school fitness between January and July 1997. The infection status of the children and of the accompanying mother was determined by the 13C-urea breath test. The parents provided additional information through a standardized questionnaire.

RESULTS

In all, 946 children (mean age 5.9 years) and their mothers were included in the final analysis (response in study population 80.2%). Overall, H. pylori prevalence was 9.8% in children and 34.7% in their mothers; there was a strong association between children's and mother's infection. Of the children, 82.5% had ever been breastfed. Prevalence of H. pylori infection was higher in children breastfed compared to never breastfed children (10.1% versus 8.4%) and showed a positive relationship with duration of breastfeeding. After controlling for covariates, including mother's H. pylori status, by means of multivariable analysis, the odds ratio (OR) for children's H. pylori infection was 1.56 (95% CI: 0.79-3.11) for any versus never breastfeeding and 2.57 (95% CI: 1.19-5.55) given the child was breastfed > or =6 months.

CONCLUSIONS

These data suggest that breastfeeding in infancy does not protect against H. pylori infection among pre-school children in industrialized countries.

The design of vaccines against Helicobacter pylori and their development

Helicobacter pylori is a gram negative, spiral, microaerophylic bacterium that infects the stomach of more than 50% of the human population worldwide. It is mostly acquired during childhood and, if not treated, persists chronically, causing chronic gastritis, peptic ulcer disease, and in some individuals, gastric adenocarcinoma and gastric B cell lymphoma. The current therapy, based on the use of a proton-pump inhibitor and antibiotics, is efficacious but faces problems such as patient compliance, antibiotic resistance, and possible recurrence of infection. The development of an efficacious vaccine against H. pylori would thus offer several advantages. Various approaches have been followed in the development of vaccines against H. pylori, most of which have been based on the use of selected antigens known to be involved in the pathogenesis of the infection, such as urease, the vacuolating cytotoxin (VacA), the cytotoxin-associated antigen (CagA), the neutrophil-activating protein (NAP), and others, and intended to confer protection prophylactically and/or therapeutically in animal models of infection. However, very little is known of the natural history of H. pylori infection and of the kinetics of the induced immune responses. Several lines of evidence suggest that H. pylori infection is accompanied by a pronounced Th1-type CD4(+) T cell response. It appears, however, that after immunization, the antigen-specific response is predominantly polarized toward a Th2-type response, with production of cytokines that can inhibit the activation of Th1 cells and of macrophages, and the production of proinflammatory cytokines. The exact effector mechanisms of protection induced after immunization are still poorly understood. The next couple of years will be crucial for the development of vaccines against H. pylori. Several trials are foreseen in humans, and expectations are that most of the questions being asked now on the host-microbe interactions will be answered.

Helicobacter pylori infection in Swedish school children: lack of evidence of child-to-child transmission outside the family

BACKGROUND & AIMS

Helicobacter pylori infection is mainly acquired in early childhood, but the exact routes of transmission remain elusive. To distinguish between risks of intrafamilial and extraneous child-to-child transmission, we studied H. pylori seroprevalence among Swedish school children with varying family backgrounds.

METHODS

In a cross-sectional study, 695 of 858 (81%) 10-12-year-olds in 36 school classes in Stockholm donated blood and answered a questionnaire. Infection was detected by enzyme-linked immunosorbent assay and confirmed by immunoblot and urea breath test.

RESULTS

Overall, 112 (16%) children were infected. The seroprevalence was 2% among 435 children with Scandinavian parents and 55% among 144 children with origin in high prevalence areas (Middle East and Africa). Among children born in Scandinavia, the odds ratios (adjusted for gender, socioeconomic status, and family size) for being seropositive were 39.1 (95% confidence interval, 16.7-91.3) and 5.6 (1.8-17.3) when having parents born in high and medium prevalence areas, respectively, relative to children with Scandinavian parents. Importantly, the prevalence of infection among the classmates was not a risk factor for H. pylori infection.

CONCLUSION

Our data indicate that intrafamilial transmission is far more important than child-to-child transmission outside the family. The H. pylori prevalence in the parental generation may be a crucial determinant for the child's risk of contracting the infection.

A systematic review of Helicobacter pylori eradication treatment schedules in children

METHODS

We systematically reviewed all available data in the paediatric literature on treatment for Helicobacter pylori infection to determine overall efficacy of different schedules. A comprehensive search of all published articles and letters from 1987, and of abstracts presented at three main meetings on this topic between 1997 and 1999, was carried out. Results from all English and French papers, letters and abstracts were extracted and analysed.

RESULTS

Only 30 full articles and 16 abstracts were found, with results on eradication of H. pylori in 870 and 1552 children, respectively. Monotherapy or dual therapy with an antisecretory drug plus one antibiotic showed a very low efficacy. Dual therapies with bismuth plus one antibiotic (either amoxycillin or a nitro- imidazole) or two antibiotics when administered for 2 or more weeks were as effective as either bismuth-based or proton pump inhibitor-based triple therapies. Triple therapies were less effective than in adults, and while bismuth-based triple therapies were more effective when given for 2 weeks than for one week, proton pump inhibitor-based triple therapies have a similar efficacy irrespective of the duration.

CONCLUSION

In children dual therapies seemed as effective as triple therapies, and longer courses of proton pump inhibitor-base triple therapies are not better than shorter ones.

A comprehensive review of the natural history of Helicobacter pylori infection in children

Across populations of children, Helicobacter pylori prevalence ranges from under 10% to over 80%. Low prevalence occurs in the U.S., Canada, and northern and western Europe; high prevalence occurs in India, Africa, Latin America, and eastern Europe. Risk factors include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; however, it is consistently associated with antral gastritis, although its clinical significance is unclear. Duodenal ulcers associated with H. pylori are seldom seen in children under 10 years of age. H. pylori-infected children demonstrate a chronic, macrophagic, and monocytic inflammatory cell infiltrate and a lack of neutrophils, as compared with the response observed in adults. The effect of H. pylori infection on acid secretion in children remains poorly defined. The events that occur during H. pylori colonization in children should be studied more thoroughly and should include urease activity, motility, chemotaxis, adherence, and downregulation of the host response. The importance of virulence determinants described as relevant for disease during H. pylori infection has not been extensively studied in children. Highly sensitive and specific methods for the detection of H. pylori in children are needed, especially in younger pediatric populations in which colonization is in its early phases. Criteria for the use of eradication treatment in H. pylori-infected children need to be established. Multicenter pediatric studies should focus on the identification of risk factors, which can be used as prognostic indicators for the development of gastroduodenal disease later in life.

Does maternal smoking hinder mother-child transmission of Helicobacter pylori infection?

Evidence for early childhood as the critical period of Helicobacter pylori infection and for clustering of the infection within families suggests a major role of intrafamilial transmission. In a previous study, we found a strong inverse relation between maternal smoking and H. pylori infection among preschool children, suggesting the possibility that mother-child transmission of the infection may be less efficient if the mother smokes. To evaluate this hypothesis further, we carried out a subsequent population-based study in which H. pylori infection was measured by 13C-urea breath test in 947 preschool children and their mothers. We obtained detailed information on potential risk factors for infection, including maternal smoking, by standardized questionnaires. Overall, 9.8% (93 of 947) of the children and 34.7% (329 of 947) of the mothers were infected. Prevalence of infection was much lower among children of uninfected mothers (1.9%) than among children of infected mothers (24.7%). There was a strong inverse relation of children's infection with maternal smoking (adjusted odds ratio = 0.24; 95% confidence interval = 0.12-0.49) among children of infected mothers, but not among children of uninfected mothers. These results support the hypothesis of a predominant role for mother-child transmission of H. pylori infection, which may be less efficient if the mother smokes.