Helicobacter pylori is a human-specific pathogen which leads to gastric pathologies including gastric cancer. It is a highly unique bacterium considered as a carcinogenic agent. H. pylori remains a major human health problem, responsible for ~90% of the gastric cancer cases. Approximately four billion individuals have been detected for H. pylori infection worldwide in 2015. At the turn of the 21 st century, the prevalence of H. pylori has been declining in highly industrialized countries of the Western world, whereas prevalence has plateaued at a high level in developing and newly industrialized countries. However, the infection status remains high in immigrants coming from countries with high prevalence of H. pylori infection. H. pylori can be diagnosed by invasive and non-invasive methods. Urea breath test and stool antigens detection are among the most commonly used non-invasive ones. Although the way H. pylori is transmitted remains still unclear, the level of contamination is strongly dependent on the familial and environmental context, with a drastic impact of living conditions with poor hygiene and sanitation. However, familial socioeconomic status is the main risk factor for H. pylori infection among children. In addition, food and water source have a high impact on the prevalence of H. pylori infection worldwide. This chapter highlights the latest knowledge in the epidemiology of H. pylori infection, its diagnosis and critical risk factors responsible for its high prevalence in some populations and geographic areas.

Adherence to therapy is a very important factor for the outcome and has to be assessed when evaluating the outcome of an H. pylori eradication regimen in order to understand the reasons of treatment failure. As we treated only after evaluation of the resistance of the H. Pylori strains, we were expecting to reach the given objective of 90% successful treatment. Children with adherence to treatment above 90% had a successful outcome of 89,9%, whereas nonadherent had a successful outcome of 36,8%. This is the first time that adherence has been assessed accurately.

Helicobacter pylori infection is acquired mainly in childhood and remains an essential cause of peptic ulcer disease and gastric cancer. This article provides commentary on the last ESPGHAN/NASPGHAN guidelines and on publications made after the consensus conference of 2015. The majority of infected children are asymptomatic and pediatric studies do not support a role for H. pylori in functional disorders such as recurrent abdominal pain. The role of H. pylori infection in failure to thrive, children's growth, type I diabetes mellitus (T1DM), and celiac disease remains controversial. The diagnosis of infection should be based on upper-digestive endoscopy with biopsy-based methods. Eradication control after treatment should be based on validated non-invasive tests. Nodular gastritis is the main endoscopic finding of childhood H. pylori infection, but gastroduodenal erosions/ulcers are seen in some children, especially after 10 years of age. When indicated, eradication treatment should be given when good compliance is expected and based on the antimicrobial susceptibility profile.

Vitamin B12 (B12) is essential for deoxyribonucleic acid synthesis, to maintain normal hematologic and neurologic functions. Studies suggest that cobalamin deficiency in children is more common than previously recognized. Main causes are decreased intake, abnormal absorption, and inborn errors of metabolism. The classic treatment for cobalamin deficiency is intramuscular administration of B12. There are no data concerning the use of alternative routes of cobalamin administration in children. This report shares the experience of sublingual administration of B12 to a patient with short-bowel syndrome and B12 malabsorption. We report the case of successful treatment of cobalamin deficiency by sublingual administration in a 9-year-old patient who had undergone intestinal resection and jejunum-colon, with anastomosis of 32 cm of residual small intestine and absence of distal jejunum and ileocecal junction. We determined a B12 deficiency because low serum cobalamin levels (<200 pg/mL) were shown in 2 consecutive tests (130 pg/mL and 170 pg/mL). The patient presented with neither clinical nor hematological manifestations. He received sublingual cobalamin preparation, 1000-mcg sublingual nuggets per day for 1 month. Normalization of serum cobalamin was obtained (790 pg/mL) after 1 month of treatment. The sublingual route of administration not only improved the quality of life of this patient by avoiding monthly painful injections but also reduced the cost of treatment and the number of hospital visits.

Purpose The EuroPedHp-registry aims to monitor guideline-conform management, antibiotic resistance, and eradication success of 2-week triple therapy tailored to antibiotic susceptibility (TTT) in Helicobacter pylori-infected children. Methods From 2017 to 2020, 30 centres from 17 European countries reported anonymized demographic, clinical, antibiotic susceptibility, treatment, and follow-up data. Multivariable logistic regression identified factors associated with treatment failure. Results Of 1605 patients, 873 had follow-up data (53.2% female, median age 13.0 years, 7.5% with ulcer), thereof 741 (85%) treatment naïve (group A) and 132 (15%) after failed therapy (group B). Resistance to metronidazole was present in 21% (A: 17.7%, B: 40.2%), clarithromycin in 28.8% (A: 25%, B: 51.4%), and both in 7.1% (A: 3.8%, B: 26.5%). The majority received 2-week tailored triple therapy combining proton pump inhibitor (PPI), amoxicillin with clarithromycin (PAC) or metronidazole (PAM). Dosing was lower than recommended for PPI (A: 49%, B: 41%) and amoxicillin (A: 6%, B: 56%). In treatment naïve patients, eradication reached 90% (n = 503, 95% CI 87–93%) and 93% in compliant children (n = 447, 95% CI 90–95%). Tailored triple therapy cured 59% patients after failed therapy (n = 69, 95% CI 48–71%). Treatment failure was associated with PAM in single clarithromycin resistance (OR = 2.47, 95% CI 1.10–5.53), with PAC in single metronidazole resistance (OR = 3.44, 95% CI 1.47–8.08), and with low compliance (OR = 5.89, 95% CI 2.49–13.95). Conclusions Guideline-conform 2-weeks therapy with PPI, amoxicillin, clarithromycin or metronidazole tailored to antibiotic susceptibility achieves primary eradication of ≥ 90%. Higher failure rates in single-resistant strains despite tailored treatment indicate missed resistance by sampling error.

Background: Recent data suggest that in children, the proportion of gastroduodenal ulcers/erosions associated with Helicobacter pylori infection is currently lower than expected. In this study, we trace this proportion over two decades. Methods:We reviewed the reports of all upper gastrointestinal endoscopies with biopsies for histology and culture over the past 23 years. H pylori status was assessed using several invasive methods. The infection rate during different time periods was compared between children with lesions and controls. Results: A total of 7849 endoscopies were performed in 5983 children (2874 F/3109 M, median age 7.6 years, range 0.1-17.9 years). The endoscopy report was missing in 316 patients. At the first upper gastrointestinal endoscopy, 12.1% of the children presented with gastric and/or duodenal ulcers or erosions with an H pylori infection rate of 35.4%, whereas no such lesions were observed in 87.9% of children in whom the H pylori infection rate was 21.3%. The risk factors associated with such lesions were older age (P < 0.001), male sex (P = 0.002), and H pylori infection (P < 0.0001). Gastric ulcers were not significantly associated with H pylori (24% infected), whereas 52% of duodenal ulcers, 33% of gastric erosions, and 38% of duodenal erosions were associated with H pylori. The proportion of gastroduodenal lesions associated with H pylori remained stable over time. Children with H pylori infection and ulcers were older than those with H pylori infection without ulcers (P < 0.001). Conclusions:Our study indicates that in our pediatric population, the proportion of ulcers without H pylori infection is higher than previously suggested, and this prevalence has not changed over the past two decades. K E Y W O R D Schildren, Helicobacter pylori, peptic ulcer disease

Objectives: To evaluate the efficacy and safety of a 10-day quadruple therapy containing colloidal bismuth sub-citrate (CBS), esomeprazole (ESO), amoxicillin (AMO), and metronidazole (MET) for Helicobacter pylori (H. pylori) eradication in children. Methods: Monocentric, open-label, prospective, single-arm clinical trial in children aged 6-17 years with H. pylori infection. The study was carried out on consecutive patients with upper gastrointestinal symptoms and H. pylori infection confirmed by histology and culture of gastric biopsies. The outcome was evaluated using a 13 C-urea breath test 8-10 weeks post-therapy. Adverse events and compliance were evaluated by daily journal and pill counting. Results: A total of 36 children fulfilling the inclusion criteria were enrolled. Eight (22.2%) of them had a prior H. pylori eradication treatment. Thirteen (36.1%) patientswere infected by a strain resistant to MET and 8 (22.2%) by a strain resistant to both MET and Clarithromycin (CLA). In the intention-to-treat population (ITT), eradication was achieved in 35/36 patients (95%CI: 85%−99%). Twenty-three children reported at least one adverse event (63.8%), mostly mild (nausea, vomiting, abdominal pain, diarrhea, dark stool, metallic taste, headache, and rash). The compliance rate was high, with 30 (83.3%) patients taking >90% of the treatment. Conclusion:10-day quadruple therapy containing CBS, ESO, AMO, and MET for H. pylori eradication in children is a safe and very effective solution, especially for previously treated patients and those infected with double resistant strains.

Helicobacter pylori (H. pylori) infection causes chronic gastritis, peptic ulcers and gastric cancer. Although H. pylori prevalence is decreasing worldwide, regional variations exist in Europe, with the lowest infection prevalence in Northern Europe, and the highest in Eastern and Southern Europe (1). Changes in the treatment recommendations and the increasing available evidence have justified the implementation of new recommendations since last Belgian consensus in 1998 (2). Several non-H. pylori Helicobacter species (NH.PYLORI-H), colonizing the stomach of domestic animals, also have the ability to cause gastric disease in humans, although to a lesser extent. These zoonotic NH. PYLORIH are not the subject of the current recommendations.