Treatment of Helicobacter pylori infection: a review

The efficacy of a 1-week triple therapy for eradication of Helicobacter pylori infection in children

BACKGROUND AND STUDY AIMS

Poor compliance to therapy and antibiotic resistance are the main causes for failure of anti-Helicobacter pylori (H. pylori) therapy. The purpose of this study was to assess the effectiveness of omeprazole-based triple therapy in Iranian children.

PATIENTS AND METHODS

Fifty-seven children with H. pylori-related gastroduodenal disease received 1-week triple therapy with a combination of omeprazole, amoxicillin and clarithromycin (according to the susceptibility test). Success of eradication was assessed by (13)C-urea breath test and endoscopy.

RESULTS

Sixty-four patients (mean age 11.3years; range 2.7-16years) were included. Eradication was successful in 84.2% (95% confidence interval, 72.8% intention to treat).

CONCLUSION

One-week triple therapy was effective for the eradication of H. pylori infection in children.

Exposure to antibiotics in a United States-Mexico border birth cohort

OBJECTIVE

The goal was to compare the frequency of children's antibiotic intake, emphasizing antibiotics with anti-Helicobacter pylori effects, in El Paso, Texas, and Juarez, Mexico.

METHODS

Hispanic children were enrolled prenatally at mother-child clinics in El Paso, and Juarez, in 1998-2000, to identify determinants of H pylori infection. During follow-up examinations targeted every 6 months from 6 to 84 months of age, caretakers reported medication use during the preceding interval. Courses of any systemic and H pylori-effective antibiotics were compared for US and Mexican children.

RESULTS

Antibiotic data were available for 602 children, from 2938 follow-up visits. Overall antibiotic intake was higher in Juarez, where 84% of children received > or = 1 course during the follow-up period (52% of visits), compared with El Paso, where 76% of children received > or = 1 course (40% of visits). In contrast, the intake of H pylori-effective antibiotics was higher in El Paso, where 65% of children received > or = 1 course during the follow-up period (27% of visits), compared with Juarez, where 44% of children received > or = 1 course (16% of visits). Of H pylori-effective courses, 94% contained amoxicillin and 2% each clarithromycin, metronidazole, and furazolidone; uses were primarily for throat and ear infections, diarrhea, and cold/flu.

CONCLUSIONS

Pediatric antibiotic use was higher in Mexico than on the US side of the border. Apparent misuse of H pylori-effective antibiotics was more frequent in Juarez but also occurred in El Paso. Such misuse of antibiotics may lead to drug resistance and may impair the control of H pylori infection in this region.

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.

Colloidal bismuth subcitrate-based twice-a-day quadruple therapy as primary or salvage therapy for Helicobacter pylori infection

OBJECTIVE

Helicobacter pylori (H. pylori) eradication rates in northern Sardinia using standard 1-wk triple therapies (i.e., a proton pump inhibitor and two antibiotics) are typically <60%, primarily because of antibiotic resistance. The aim of this study was to test b.i.d. quadruple therapy as primary and as salvage therapy in this population.

METHODS

This was a prospective, single center study of consecutive dyspeptic H. pylori-infected patients. Therapy consisted of omeprazole 20 mg, tetracycline 500 mg, metronidazole 500 mg, and bismuth subcitrate caplets 240 mg, all b.i.d. with the midday and evening meals for 14 days. H. pylori status was evaluated by 13C-urea breath test and histology before and 4-6 wk after therapy. Eradication was defined as no positive test.

RESULTS

We enrolled 118 consecutive dyspeptic patients (mean age 46 yr; 73 men, including 15 with peptic ulcer disease). Of the patients, 42 (38%) had failed prior therapy: twice in 21 cases, three times in 12, and four or more times in nine. The intention-to-treat cure rate was 95% (110 of 116) (95% CI = 90-98%) overall, and 98% per protocol, irrespective of diagnosis, age, prior treatment failure, or smoking status. Moderate or severe side effects were experienced by only 5% of patients.

CONCLUSIONS

Bismuth subcitrate-based b.i.d. quadruple therapy was an excellent primary and salvage therapy and should be considered as first line therapy.

Sources of variation of Helicobacter pylori treatment success in adults worldwide: a meta-analysis

BACKGROUND

A vast number of Helicobacter pylori treatment trials have been conducted. Regimens may vary in efficacy in different patient populations.

METHODS

We identified sources of treatment effect variation from 618 treatment groups using weighted cross-classified multi-level meta-regression models. Summary effect estimates were calculated within groups that lacked identified heterogeneity.

RESULTS

Overall, treatment was less successful with shorter treatment duration and dual drug (versus triple or quadruple drug) therapies. For nitroimidazole-based regimens, treatment was less successful in populations with frequent childhood H. pylori infection or metronidazole resistance and more successful in northeastern Asia. Non-nitroimidazole treatments of longer duration and those from less recent reports were most successful. Some one-week regimens--(nitroimidazole/ tetracycline/bismuth, ranitidine bismuth citrate/amoxicillin/clarithromycin, and clarithromycin/amoxicillin/proton pump inhibitor) were highly successful in northeastern Asia regardless of metronidazole resistance. The most successful regimen in populations with both a high prevalence of metrondiazole resistance and frequent infection in children (metronidazole/furazolidone/amoxicillin) eliminated fewer than 70% of infections.

CONCLUSIONS

More effective treatments are needed for most populations of the world where H. pylori infection in children and drug resistance are common. Current treatment guidelines do not coincide with the best treatment regimens identified in this meta-analysis.

Helicobacter pylori infection in children

A number of scientific breakthroughs since H pylori first became recognized as a human pathogen have increased our understanding of the pathogenesis of gastroduodenal disease. In particular, advances in molecular bacteriology and the complete sequencing of the H pylori genome in 1999, and soon thereafter the human genome, provide tools allowing better delineation of the pathogenesis of disease. These molecular tools for both bacteria and host should now be applied to multicenter pediatric studies that evaluate disease outcome. More recent developments indicate that a better understanding of the microbial-host interaction is critical to furthering knowledge with respect to H pylori-induced diseases. Studies are needed to evaluate either DNA-based or more traditional protein-based vaccines, to evaluate more specific antimicrobials that confer minimal resistance, and to evaluate probiotics for the management of H pylori infection. Multicenter multinational studies of H pylori infection in the pediatric population, which include specific, randomized controlled eradication trials, are essential to extend current knowledge and develop better predictors of disease outcome.

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.

Efficacy of bismuth-based triple therapy in children with abdominal pain and Helicobacter pylori gastritis

BACKGROUND

To evaluate the effect of a therapeutic regimen of 7 days versus 14 days on the clinical manifestations of Helicobacter pylori gastritis in children.

METHODS

Ninety children (age 2-19 years) who had abdominal pain and/or recurrent vomiting were determined to have H. pylori gastritis by endoscopy, histology, and a Giemsa stain positive for H. pylori. The patients were randomized to receive amoxicillin, metronidazole, and bismuth subcitrate for 7 days (group A; 45 children) or 14 days (group B; 45 children) and were observed clinically for 19 +/- 11.5 months. Resolution of all abdominal and gastrointestinal symptoms was considered a good response.

RESULTS

A good response was obtained in 36 (80%) children from group A, and in 37 (82%) from group B. A recurrence of symptoms occurred in four (11%) of the responders from group A, and in six (15.2%) from group B.

CONCLUSIONS

A 7-day course of bismuth-based triple therapy for H. pylori gastritis in children appears to be clinically as effective as a 14-day regimen. The feasibility of a shorter therapeutic regimen may enhance patient compliance and provide a better chance of clinical benefit.

Pretreatment antibiotic resistance in Helicobacter pylori infection: results of three randomized controlled studies

BACKGROUND

Although combinations of antibiotics and antisecretory drugs are useful for treatment of Helicobacter pylori infection, treatment failure is common. The aim of this study was to evaluate the relation between pretreatment antibiotic resistance and outcome by using six different treatment regimens for H. pylori infection.

PATIENTS AND METHODS

Three hundred sixty-nine consecutive H. pylori-infected patients with dyspeptic symptoms were enrolled in three consecutive randomized, controlled, single-center clinical trials: trial A, 128 patients; trial B, 125 patients; trial C, 116 patients. Treatments consisted of (A) a 15-day course of dual therapy (omeprazole, 20 mg bid, and amoxicillin, 1 gm bid, or clarithromycin, 500 mg tid) (OA vs OC); (B) a 7-day triple therapy of omeprazole, 20 mg bid, plus metronidazole, 500 mg bid, and amoxicillin, 1,000 mg bid, or clarithromycin, 500 mg tid (OMA vs OMC); or (C) omeprazole, 20 mg bid, plus metronidazole, 500 mg bid, plus tetracycline, 500 mg qid, or doxycycline, 100 mg tid (OMT vs OMD). Diagnostic endoscopy was made in all patients before and 5 to 6 weeks after therapy. Six biopsies were taken from each patient for histology, rapid urease test, and H. pylori culture; antibiotic susceptibility testing was performed using the E-test method.

RESULTS

Overall cure rates were poor for both dual therapies OA and OC (38% and 37%, respectively) and for triple therapies OMA, OMC, and OMD (57%, 55%, and 58%, respectively). The OMT combination was successful in 91% (95% confidence interval [CI], 80.4%-97%). Metronidazole resistance was present in 29.7% (95% CI, 24%-35%), amoxicillin resistance was present in 26% (95% CI, 21%-32%), clarithromycin resistance was present in 23.1% (95% CI, 18%-29%), tetracycline resistance was present in 14% (95% CI, 10%-20%), and doxycycline resistance was present in 33.3% (95% CI, 21%-47%). Antibiotic resistance markedly reduced the cure rates and accounted for most of the poor results with the triple therapies: 89% versus 23%; 77% versus 26%; 100% versus 60%; and 67% versus 23% for OMC, OMA, OMT, and OMD, respectively. OMT appeared to be the best because of the high success rate with metronidazole-resistant H. pylori (71%) and in low-level tetracycline resistance.

CONCLUSIONS

Pretreatment antibiotic-resistant H. pylori can, in part, explain the low cure rate of the infection and the variability in outcome in reported trials.

Helicobacter pylori gastritis in children: efficacy of 2 weeks of treatment with clarithromycin, amoxicillin and omeprazole

Thirty-eight children with Helicobacter pylori gastritis diagnosed by histopathology, and/or bacteriological culture were treated with omeprazole, amoxicillin and clarithromycin. Follow-up endoscopy was performed in 34 children. Outcome was measured by negative histology and culture for H. pylori. Six patients were excluded. Of the 32 remaining children eradication was achieved in 75% (95% confidence interval 60-90%).