Utility of stool sample-based tests for the diagnosis of Helicobacter pylori infection in children

Helicobacter pylori Infection in Children With Cerebral Palsy: A Cross-Sectional Study

BACKGROUND

Children with cerebral palsy (CP) frequently have associated disorders and complications, including gastrointestinal problems. Helicobacter pylori is a common infection worldwide, frequently associated with gastrointestinal manifestations.

METHODS

To estimate the prevalence of H. pylori infection in children with CP, a cross-sectional study over an eight-month period was performed in the pediatric neurology outpatient clinic of Tanta University Hospital. The study included 100 patients with CP aged two to 17 years. All patients were tested for H. pylori antigen in stool by enzyme-linked immunosorbent assay.

RESULTS

The mean age of studied children with CP was 7.03 ± 4.1 years; there were 57 males and 43 females. Spastic quadriplegic CP was the most common type of CP (34%). Forty-five children with CP were positive for H. pylori antigen in stool. Intellectual disability (ID), low sociodemographic scoring system, semisolid diet, and Eating and Drinking Ability Classification System (EDACS) levels 4 and 5 were significant predictors of H. pylori infection (odds ratio of 1.86, 2.63, 12, and 1.77, respectively, P < 0.05). Vomiting, abdominal pain, and gastrointestinal tract bleeding were significantly more frequent in H. pylori-infected children with CP than noninfected children with CP (P value < 0.05) CONCLUSION: H. pylori is a relatively common infection among children with CP. The main risk factors for H. pylori infection were low socioeconomic level, ID, semisolid diet, and EDACS levels 4 and 5.

Helicobacter pylori-Induced Gastroduodenal Stricture in a Child

Helicobacter pylori is a known cause of peptic ulcers, but it has not been reported to cause strictures in children. We present the case of a previously healthy 12-year-old boy with sudden onset of abdominal pain and vomiting, positive stool H. pylori antigen testing, and esophagogastroduodenoscopy revealing a gastroduodenal stricture causing gastric outlet obstruction. Because of medically refractory disease, he ultimately required laparoscopic truncal vagotomy with open pyloroplasty. This is an unusually severe presentation and may warrant H. pylori being on the differential of pediatric gastrointestinal strictures as well as further discussion on other long-term implications.

Advances on diagnosis of Helicobacter pylori infections

The association of Helicobacter pylori to several gastric diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer, and its high prevalence worldwide, raised the necessity to use methods for a proper and fast diagnosis and monitoring the pathogen eradication. Available diagnostic methods can be classified as invasive or non-invasive, and the selection of the best relies on the clinical condition of the patient, as well as on the sensitivity, specificity, and accessibility of the diagnostic test. This review summarises all diagnostic methods currently available, including the invasive methods: endoscopy, histology, culture, and molecular methods, and the rapid urease test (RUT), as well as the non-invasive methods urea breath test (UBT), serological assays, biosensors, and microfluidic devices and the stool antigen test (SAT). Moreover, it lists the diagnostic advantages and limitations, as well as the main advances for each methodology. In the end, research on the development of new diagnostic methods, such as bacteriophage-based H. pylori diagnostic tools, is also discussed.

ABO, Lewis blood group systems and secretory status with H.pylori infection in yemeni dyspeptic patients: a cross- sectional study

BACKGROUND

The ABO and Lewis blood group antigens are potential factors in susceptibility to H. pylori infection. This research aimed to examine the prevalence of Helicobater pylori (H.pylori) infection and its association with ABO, Lewis blood group systems, and secretory status in Yemeni symptomatic patients.

METHODS

In a cross-sectional study, 103 patients referred for endoscopy due to dyspepsia were included. H pylori infection was assessed using stool antigen and serum antibody rapid tests. ABO and Lewis blood group systems were examined using hemagglutination assay. Saliva samples were investigated for identification of the secretory phenotype using hemagglutination inhibition test.

RESULTS

The prevalence of H. pylori infection was (80.6%), with a higher rate of infection in females than males. The ABO blood groups were found to be significantly different between males and females (p = 0.047). The O blood group was prevalent among H. pylori patients, especially secretors. There was a significant association between ABO blood groups and H. pylori infection (p = 0.001). The Le (a + b+) phenotype was the most common, followed by Le (a + b-), Le (a-b+), and Le (a-b-). Lewis blood group systems and secretory status of symptomatic patients were not associated with H. pylori infection. The results showed that serum Ab test for H. pylori achieved poor sensitivity (68%), specificity of 55%; positive predictive value (PPV) 86%, negative predictive value (NPV) 29% and accuracy 65.1%.

CONCLUSION

The prevalence of H. pylori infection was high in Yemeni patients. This infection was linked to the O and Le (a + b+) secretor phenotype. The H. pylori stool Ag test is the most reliable noninvasive diagnostic method for detecting H. pylori infection.

The Importance of Accurate Early Diagnosis and Eradication in Helicobacter pylori Infection: Pictorial Summary Review in Children and Adults

Among the most widespread childhood infections, Helicobacter pylori (H. pylori) develops potentially life-threatening conditions in adults if not appropriately treated. Helicobacter pylori is a common human pathogen that was first described in the stomach many years ago. The discovery of H. pylori was crucial in gastroenterology; this bacterium is associated with chronic gastritis, peptic ulcers, gastric cancer, and lymphoid tissue lymphoma related to the gastric mucosa. Studies published so far estimate that approximately 10% of subjects infected with H. pylori develop a peptic ulcer, and 1-3% of subjects develop gastric cancer. The clinical manifestations are variable and characteristically depend on the individual factors of the host. Various methods of detection and diagnosis of H. pylori infection have been developed, each with advantages, disadvantages, and/or limitations. Available diagnostic tests are usually performed using invasive (endoscopy, biopsy, rapid urease test, cultures, and molecular tests) and noninvasive methods (urea breath test, stool antigen examination, and serological and molecular tests). Although there is extensive accessibility for diagnosing and treating H. pylori infection, the prevalence of antibiotic resistance is not negligible. Thus, numerous studies and meta-analyses are focused on a new orientation of gastroenterologists in diagnosing and treating H. pylori infections. A fascinating perspective hypothesis is the administration of probiotics to reduce H. pylori adhesion to gastric epithelial cells, preventing H. pylori colonization, especially in children, or reinfection with H. pylori in high-risk adult patients.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Evaluation of a New Monoclonal Chemiluminescent Immunoassay Stool Antigen Test for the Diagnosis of Helicobacter pylori Infection: A Spanish Multicentre Study

The stool antigen test (SAT) represents an attractive alternative for detection of Helicobacter pylori. The aim of this study was to assess the accuracy of a new SAT, the automated LIAISON® Meridian H. pylori SA based on monoclonal antibodies, compared to the defined gold standard 13C-urea breath test (UBT). This prospective multicentre study (nine Spanish centres) enrolled patients ≥18 years of age with clinical indication to perform UBT for the initial diagnosis and for confirmation of bacterial eradication. Two UBT methods were used: mass spectrometry (MS) including citric acid (CA) or infrared spectrophotometry (IRS) without CA. Overall, 307 patients (145 naïve, 162 with confirmation of eradication) were analysed. Using recommended cut-off values (negative SAT < 0.90, positive ≥ 1.10) the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 67%, 97%, 86%, 92% and 91%, respectively, obtaining an area under the receiver operating characteristic (ROC) curve (AUC) of 0.85. Twenty-eight patients, including seven false positives and 21 false negatives, presented a discordant result between SAT and UBT. Among the 21 false negatives, four of six tested with MS and 11 of 15 tested with IRS presented a borderline UBT delta value. In 25 discordant samples, PCR targeting H. pylori DNA was performed to re-assess positivity and SAT accuracy was re-analysed: sensitivity, specificity, positive predictive value, negative predictive value, accuracy and AUC were 94%, 97%, 86%, 99%, 97% and 0.96, respectively. The new LIAISON® Meridian H. pylori SA SAT showed a good accuracy for diagnosis of H. pylori infection.

Helicobacter pylori Infection in a Pediatric Population from Romania: Risk Factors, Clinical and Endoscopic Features and Treatment Compliance

Background and Objectives: The aim of this study was to investigate the association between H. pylori positivity with specific symptoms, risk factors and endoscopic patterns among the pediatric population in northeastern Romania. Materials and Methods: A prospective study was performed in 18 months on 185 children aged 6−18 years with an indication for upper digestive endoscopy. Demographic, anamnestic, symptomatic, endoscopic and histologic data were recorded. Results: Of 116 H. pylori-positive children, the most affected group was 15−17 years. Most (65.5%) of them were girls, with a significant association (p < 0.001). The majority (66.4%) lived in a rural area and 47.4% of children had an unsafe source of water and lived in overcrowded houses with no basic sanitary comfort. The most frequent symptom was epigastric pain (56.9%), and the main endoscopic appearance was nodularity and hyperemia. Patients diagnosed with H. pylori started triple-therapy treatment for 14 days. Only 13.8% stopped the treatment, mainly because of a misunderstanding of the treatment protocol (9.5%). Conclusions: Romanian teen girls living in rural areas are at high risk for H. pylori infection. Epigastric pain and endoscopic nodularity of the gastric mucosa were associated with the infection. As the resistance of the bacteria is unknown in our country, future research is needed in order to improve the eradication rate.

Evolution of Diagnostic Methods for Helicobacter pylori Infections: From Traditional Tests to High Technology, Advanced Sensitivity and Discrimination Tools

Rapid diagnosis and treatment application in the early stages of H. pylori infection plays an important part in inhibiting the transmission of this infection as this bacterium is involved in various gastric pathologies such as gastritis, gastro-duodenal ulcer, and even gastric neoplasia. This review is devoted to a quick overview of conventional and advanced detection techniques successfully applied to the detection of H. pylori in the context of a compelling need to upgrade the standards of the diagnostic methods which are currently being used. Selecting the best diagnostic method implies evaluating different features, the use of one or another test depending on accessibility, laboratories equipment, and the clinical conditions of patients. This paper aims to expose the diagnosis methods for H. pylori that are currently available, highlighting their assets and limitations. The perspectives and the advantages of nanotechnology along with the concept of nano(bio)sensors and the development of lab-on-chip devices as advanced tools for H. pylori detection, differentiation, and discrimination is also presented, by emphasizing multiple advantages: simple, fast, cost-effective, portable, miniaturized, small volume of samples required, highly sensitive, and selective. It is generally accepted that the development of intelligent sensors will completely revolutionize the acquisition procedure and medical decision in the framework of smart healthcare monitoring systems.

Increased Antibiotic Resistance in Children with Helicobacter pylori Infection: A Retrospective Study

Children with recurrent abdominal pain may be suffering from a Helicobacterpylori (HP) infection. The gold standard for confirming HP gastritis is histological evaluation and microbiological tests performed on specimens collected by esophagogastroduodenoscopy (EGD). The aim of this study was to analyze HP positive cultures and antibiograms with regard to clinical and histopathological correlates. The data of 124 subjects with frequent gastrointestinal symptoms who underwent an EGD were retrospectively collected and analyzed. The mean age of the patients was 13 ± 3.6 years. The most frequent complaints were epigastric pain (84%; n = 100/119) and dyspepsia (79%; n = 94/119). HP gastritis was diagnosed in 54% (n = 67). Interestingly, 40% (n = 49) of the isolates were resistant to at least one antibiotic: amoxicillin (20%; n = 10/49), clarithromycin (45%; n = 22/49), or metronidazole (59%; n = 29/49). Isolates were resistant to two or more antibiotics in 16% (n = 20) of cases. In conclusion, we revealed remarkably high resistance rates to amoxicillin, metronidazole, and clarithromycin in our cohort. The presence of antibiotic resistance to more than one antibiotic was substantially increased in our HP-infected patients and this may negatively affect eradication treatment.

Recent Changes in the Treatment of Helicobacter pylori Infection in Children and Adolescents

Treatments aimed at eradicating Helicobacter pylori (H. pylori) infections in children and adolescents should be clearly beneficial. According to the updated guidelines, a 14-day triple therapy or bismuth-based triple therapy is the first choice for treatment of children based on the results of antimicrobial sensitivity testing. Though culturing H. pylori using biopsy specimens is not always feasible, it should be performed for establishing empirical rescue therapy for patients not responding to first-line eradication therapy. The European and North American therapeutic strategies for children and adolescents with H. pylori infections may not be appropriate for treating children and adolescents in other countries owing to regional differences in epidemiological characteristics of H. pylori. The existence of clarithromycin-resistant H. pylori is an important factor involved in eradication failure. The development of new treatment-related allergies, treatment failure, side effects, and alteration of the gut microbiome have been highlighted as factors potentially outweighing the possible benefit of preventing future peptic ulcers or gastric cancer. Drug compliance can be improved by providing a detailed explanation of the reason for therapy, duration, and routes of drug administration. Physicians should understand the mechanisms underlying eradication treatment and explain drug prescriptions in detail to both parents and children to increase compliance. Herein, we reviewed the indications for and various modalities of eradication treatment in children with H. pylori infections in accordance with a review of recently published articles.

Methods for detection of Helicobacter pylori from stool sample: current options and developments

Accurate detection of Helicobacter pylori infection and determination of antibiotics have significant meaning in clinical practice. The detection methods can be categorized into two types, invasive and non-invasive, but nowadays we use the urease breath test most frequently which is non-invasive. However, many developing countries cannot meet the requirements for having specialized equipment and they lack trained personnel. Also, for the children, it is difficult to make them cooperate for the test. Methods that detect Helicobacter pylori from stool sample can be a promising alternative for detection used in children and mass screening. Stool antigen tests have several advantages such as rapidity, simplicity, and cheapness, though their results may be influenced by the heterogenicity of antigens, the nature of biochemical techniques, and the amount of antigen presented in the stool. PCR-based methods can specifically detect Helicobacter pylori infection and antibiotic resistance by targeting specific gene sequence, but they also are limited by the requirements of facilities and experts, the existence of inhibitory substance, and interference from the dead bacteria. Some novel methods also deserve our attention. Here we summarized the results of researches about methods using stool sample and we hope our work can help clinicians choose the appropriate test in clinical practice.

Helicobacter pylori infection in patients with metabolic syndrome, with or without nonalcoholic fatty liver disease

Background

Helicobacter pylori (HP) infection is considered a risk factor of GIT diseases, e.g., gastric and duodenal ulcers and gastric carcinomas. It is transmitted through feco/oral route and can be diagnosed by many methods, e.g., stool antigen test (SAT). Metabolic syndrome (MET S) is considered a circle of metabolic derangements that can cause some complications as ischemic changes and heart diseases. Metabolic syndrome may also cause nonalcoholic fatty liver disease (NAFLD) resulting in liver fibrosis, cirrhosis, and HCC.

Results

The study included 300 subjects recruited from Obesity Clinic and Diabetes & Endocrinology Unit, Specialized Medical Hospital, Mansoura University. Two hundred of metabolic syndrome patients were subdivided into two groups according to the presence or absence of NAFLD, in addition to 100 subjects not having metabolic syndrome and served as control group. We found that HP infection is more frequent in MET S with NAFLD patients (73%) than in MET S without NAFLD (47%) with (P value < 0.001) emphasizing that HP infection increases the risk of NAFLD development in patients with MET S.

The study proved that HP infection is associated with increased degree of fibrosis significantly (P value < 0.001) with progression to marked fibrosis which may complicate with NASH with over all predictive value of 75% especially in patients with hyperglycemia.

Conclusions

Our findings show that a circle of metabolic abnormalities seems to be attributed to HP infection in MET S patients increasing the risk of fatty liver and progression to marked fibrosis especially with coexistent hyperglycemia, dyslipidemia, and upper body obesity.

Diagnosis and early eradication of HP infection will help in decreasing metabolic disturbances and possibility of NAFLD, and protect against marked fibrosis progression.

Nanohybrid-based immunosensor prepared for Helicobacter pylori BabA antigen detection through immobilized antibody assembly with @ Pdnano/rGO/PEDOT sensing platform

The gastric colonization of human hosts by Helicobacter pylori (H. pylori) increases the risk of developing gastritis, ulcers and gastric cancer. To detect H. pylori, a nanohybrid-based BabA immunosensor is developed herein. BabA is an outer membrane protein and one of the major virulence factors of H. pylori. To design the immunosensor, an Au electrode is loaded with palladium nanoparticles (Pdnano) by electrodeposition to generate reduced graphene oxide (rGO)/poly(3,4-ethylenedioxythiophene) (PEDOT). The immobilization of these nanostructured materials imparts a large surface area and electroconductivity to bio-immune-sensing molecules (here, the BabA antigen and antibodies). After optimization, the fabricated immunosensor has the ability to detect antigens (H. pylori) in a linear range from 0.2 to 20 ng/mL with a low LOD (0.2 ng/mL). The developed immunosensor is highly specific, sensitive and reproducible. Additionally, in silico methods were employed to better understand the hybrid nanomaterials of the fabricated Pdnano/rGO/PEDOT/Au electrode. Simulations performed by molecular docking, and Metropolis Monte Carlo adsorption studies were conducted. The results revealed that the hybrid nanomaterials exhibit a stable antigen-antibody complex of BabA, yielding the lowest binding energy in relation to the electrode materials, emphasizing the functionality of the constructed electrodes in the electrochemical immunosensor.

The updated JSPGHAN guidelines for the management of Helicobacter pylori infection in childhood

The Japan Pediatric Helicobacter pylori Study Group published the first guidelines on childhood H. pylori infection in 1997. They were later revised by the Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition (JSPGHAN). The H. pylori eradication rates, when employing triple therapy with amoxicillin and clarithromycin, currently recommended as the first-line therapy of H. pylori infection in Japan, have substantially decreased, creating an important clinical problem worldwide. In Japanese adults, the "test-and-treat" strategy for H. pylori infection is under consideration as an approach for gastric cancer prevention. However, the combined North American and European pediatric guidelines have rejected such a strategy for asymptomatic children. As risk for gastric cancer development is high in Japan, determining whether the "test-and-treat" strategy can be recommended in children has become an urgent matter. Accordingly, the JSPGHAN has produced a second revision of the H. pylori guidelines, which includes discussion about the issues mentioned above. They consist of 19 clinical questions and 34 statements. An H. pylori culture from gastric biopsies is recommended, not only as a diagnostic test for active infection but for antimicrobial susceptibility testing to optimize eradication therapy. Based upon antimicrobial susceptibility testing of H. pylori strains (especially involving clarithromycin), an eradication regimen including use of the antibiotics to which H. pylori is susceptible is recommended as the first-line therapy against H. pylori-associated diseases. The guidelines recommend against a "test-and-treat" strategy for H. pylori infection for asymptomatic children to protect against the development of gastric cancer because there has been no evidence supporting this strategy.

Crime Scene Analysis Through DNA Testing of Canine Feces-A Case Report

Forensic DNA testing can play a critical role in homicide investigations. Selecting the appropriate evidence on which to perform DNA testing requires foresight and reasoning based on experience and science. Although successful DNA testing can occur using many substrates, including blood, hair, and sweat/epithelial cells, positive results can also result from testing various unorthodox samples. The authors report on a triple-murder investigation where DNA testing of dog feces at the crime scene matched DNA testing of feces found on the shoe of a suspect resulting in successful prosecution of the case.

Evaluation of RIDASCREEN® and RIDA®QUICK Helicobacter kits for Helicobacter pylori detection in stools

The diagnosis of Helicobacter pylori infection can be made by using noninvasive tests. The detection of bacterial antigens in stool samples is a technique proposed by some suppliers. The objective of this study was to evaluate retrospectively the performances of the commercially available RIDA®QUICK Helicobacter and RIDASCREEN® Helicobacter (R-Biopharm) kits in detecting H. pylori antigens in stool samples. A collection of 132 stools was used in this study: 94 stools obtained from H. pylori-negative patients and 38 stools from H. pylori-positive patients. The performances (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV)) were evaluated for the RIDA®QUICK Helicobacter and RIDASCREEN® Helicobacter kits in comparison with real-time PCR results performed on gastric biopsies as well as culture. Discordant results, with respect to H. pylori status, were checked on the same day as the test by repeating the procedure. All of the readings concerning the RIDA®QUICK Helicobacter tests were concordant between 3 users, i.e., 94/94 negative tests and 34/38 positive tests. RIDASCREEN® Helicobacter tests were negative for all 94 H. pylori-negative samples and positive for 35/38 positive stools. Reading of the RIDA®QUICK Helicobacter tests was not a problem in routine practice. The RIDA®QUICK Helicobacter and RIDASCREEN® Helicobacter kits show good performances and can be included in the armamentarium of diagnostic tests for H. pylori infection.

Clinical Performance of the Automated LIAISON® Meridian H. pylori SA Stool Antigen Test

Background

Antigens derived from Helicobacter pylori can be used as stool biomarkers to assist in the diagnosis of H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Methods

This prospective multisite study enrolled patients undergoing an esophagogastroduodenoscopy with collection of biopsy and stool specimens. Adult patients (≥22 years) participated in the study from February 2017 to August 2018. Specimens of the stomach were tested by three methods, known as the Composite Reference Method: (1) histological evaluation, (2) culture of the organism, and (3) rapid urease detection test. H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Results

277 patients (63% female) were included in the study. The prevalence of infected subjects was 24.2% in this study cohort. Clinical performance assessed against the Composite Reference Method showed very good agreement (Cohen′s kappa = 0.922), with good sensitivity (95.5%) and specificity (97.6%). Reproducibility study results showed total imprecision ranging from 3.1% to 13.9% CV.

Conclusion

The automated LIAISON® Meridian H. pylori SA assay brings reliable noninvasive testing for H. pylori to the laboratory that is in very good agreement with the current, more invasive biopsy-based methods such as histology, culture, or rapid urease test. The clinical trial identifiers are NCT03060746 (pretherapy) and NCT03060733 (posttherapy).H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Helicobacter pylori as a risk factor for gastric cancer: the evidence and primary prevention strategy

Russia is a country with a high prevalence of Helicobacter pylori (HP) infection, a high incidence of gastric cancer, and its late diagnosis. HР infection has been recognized as the leading manageable risk factor for gastric cancer. Accurate diagnostic tests must be used to identify and control the effectiveness of HP eradication, and effective schemes must be implemented for HP eradication. The aim of this article was to analyze the latest consensus documents, systematic reviews and meta-analyzes that reflected the role of HP as a risk factor for the development of gastric cancer, as well as measures for the risk reduction. We describe in detail the diagnostic methods for HP infection, provide data on their use in the Russian Federation, and analyze the efficacy of eradication regimens. In all HPinfected individuals, HP leads to chronic inflammation in the gastric mucosa and launches a precancerous cascade (Correa's cascade). The risk of gastric cancer increases with severe atrophy, intestinal metaplasia and dysplasia. Primary prevention of gastric cancer is most effective if the eradication is performed before atrophic gastritis develops. The available consensus documents underline the importance of HP infection identification by accurate diagnostics at this stage of chronic gastritis. In Russia, the primary HP diagnosis is based on histology (37.7%), rapid urease test (29.2%), and serology (29.7%). HP stool antigen test (31.3%), 13C-urea breath test (23.4%) and the histological method (23.3%) are most often used to control eradication. Currently, the first line of eradication therapy is recommended as triple therapy with clarithromycin prescribed for 14 days. It is recommended to use double dose of proton pump inhibitors and bismuth to increase the effectiveness of this scheme. A 14-days triple regimen enhanced by bismuth has been recommended as the first-line therapy in the Russian Federation.

Performances of the IDEIA HpStAR Stool Antigen Test in Detection of Helicobacter pylori Infection Before and After Eradication Treatment in Algerian Children

We aimed to evaluate in an Algerian pediatric population the diagnostic performances of the IDEIA HpStAR noninvasive stool antigen test (Oxoid, Cambridge, UK) to detect Helicobacter pylori infection before and after eradication therapy. A prospective study including 158 symptomatic Algerian children was conducted. Patients were initially diagnosed with invasive (culture, histology, and rapid urease test) and noninvasive tests (urea breath test and IDEIA HpStAR test). Infected patients were treated, and 101 were controlled after treatment with two invasive (culture and histology) and two noninvasive tests (urea breath test and IDEIA HpStAR test). In Algerian children, the IDEIA HpStAR test showed good performances for initial detection of H. pylori infection and also for subsequent control of eradication treatment. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of IDEIA HpStAR test before treatment were 93.6%, 100%, 100%, 87.3%, and 96%, respectively, and those after treatment were 100, 92.8, 78.6, 100, and 94.2%, respectively.

Accurate Detection of Helicobacter pylori Antigen in Human Stool Specimens by Two Novel Immunoassays

Stool antigen tests are recommended for the diagnosis of Helicobacter pylori infection. Here, we compared two novel assays, i.e., one enzyme immunoassay (EIA) and one immunochromatography assay (ICA), with a chemiluminescence immunoassay (CLIA) that had previously been compared with rapid urease test, histology, and urea breath test. Two hundred sixty-six frozen stool samples with defined CLIA results (42 positives, 219 negatives, and 5 samples with borderline results) collected between January and May 2018 were thawed and immediately tested by EIA, ICA, and CLIA. In 248 samples with repeatedly positive/negative CLIA results, EIA and ICA were positive for 40 and 37 of 41 CLIA-positive samples and yielded negative results for 206 and 201 of 207 CLIA-negative samples, respectively. There was a high positive percent agreement (EIA, 97.6%; 95% confidence interval (95% CI), 86.3-100%; ICA, 90.2%; 95% CI, 76.9-96.7%), as well as a negative percent agreement between the assays (EIA, 99.5%; 95% CI, 97.0-100%; ICA, 97.1%; 95% CI, 93.7-98.8%). This was further supported by kappa values indicating very good agreement (CLIA vs. EIA, 0.971; CLIA vs. ICA, 0.857). In conclusion, both EIA and ICA comprise valuable assays for the detection of H. pylori antigen in stool samples.

Helicobacter pylori: a perspective in low- and middle-income countries

BACKGROUND

In adults, Helicobacter pylori is aetiologically associated with peptic ulcer disease and gastric cancer. However, the relationship between this bacteria and gastro-intestinal symptoms in children is less clear.

AIMS

To review the recent literature on H. pylori in children and to outline the approach to diagnosis and management.

METHODS

The English language literature was searched for articles on H. pylori in children. Special attention was paid to prevalence, diagnosis and management pertinent to low- and middle-income countries (LMIC).

RESULTS

Although the prevalence of H. pylori is 60-80% in LMIC, only 5% of infected children develop peptic ulcer disease. The virulence of the organism determines the outcome. There is a suggestion that H. pylori causes iron deficiency anaemia, growth retardation and idiopathic thrombocytopenic purpura, but the evidence is not sufficiently strong to justify screening. There is no evidence to suggest a link between H. pylori infection and recurrent abdominal pain. Endoscopy (with invasive tests) is the preferred method of investigation as the primary goal is to determine the underlying cause of the symptoms. Children with H. pylori-related diseases should be treated with a standard triple-drug regimen consisting of a protein pump inhibitor and two antibiotics for 10-14 days. All treated patients should be monitored for eradication with non-invasive tests such as the urea (13-C) breath test or stool antigen tests.

CONCLUSIONS

Although H. pylori infection is common in LMIC, most children are asymptomatic. There is no association between H. pylori and recurrent abdominal pain. Invasive tests are preferred for diagnosis and a triple-drug regimen is the treatment of choice.

Non-invasive tests for the diagnosis of helicobacter pylori: state of the art

Usually, non-invasive tests are the first methods for diagnosing Helicobacter pylori (HP) infection. Among these, serological test, stool antigen research and urea breath test are the most used. Antibodies anti-HP are not recommended in low prevalence population, moreover they cannot reveal an ongoing infection, but they only prove a contact with the bacterium. Also, they can persist for a long time after the eradication of the infection, therefore, they should not be used to verify the success of eradication therapy. Stool antigen research and Urea Breath Test (UBT) are useful both in diagnosis and during follow-up after eradication treatment. The stool antigen test is cheaper than Urea breath test with similar sensitivity and specificity. Non-invasive tests are not able to diagnose the associated complications to HP infection. (www.actabiomedica.it)

Highly clarithromycin-resistant Helicobacter pylori infection in asymptomatic children from a rural community of Cajamarca-Peru

Objective

The objective of this study was to determine the prevalence of clarithromycin-resistant Helicobacter pylori in asymptomatic children in a rural community of Cajamarca (northern Peru).

Results

Helicobacter pylori was detected in 17.2% (49/285) of the samples. Unboiled water consumption the most frequent associated factor in patients with positive PCR for H. pylori infection (93.9%). Clarithromycin resistant mutations were found in 79.6% (39/49) of the positive samples for H. pylori. The most frequent mutation was A2142G (46.9%), followed by the double-mutation A2142G–A2143G (28.6%).

Helicobacter pylori antimicrobial resistance in a pediatric population

BACKGROUND

The increasing prevalence of Helicobacter pylori (H. pylori) antimicrobial resistance, primarily for clarithromycin decreases the success of treatment. The aim of this study is to determine the local pattern of first-line antimicrobials resistance and the eradication rate.

MATERIAL AND METHODS

Prospective cohort study of H. pylori infected patients (positive histological or cultural exams) treated at Centro Materno-Infantil do Norte from January of 2013 to October of 2017. Susceptibility to 4 antibiotics: amoxicilin, metronidazole, clarithromycin, and levofloxacin were analyzed by E-test (phenotypic resistance). The E-test was chosen because it is simple and cost-effective for routine susceptibility testing. Point mutations that confer clarithromycin resistance were surveyed (genotypic resistance). Eradication of H. pylori infection was defined by a negative urea breath test or fecal antigen 6-8 weeks after the end of treatment.

RESULTS

Of a total of 74 H. pylori infected patients, 16 were excluded because they had previous H. pylori treatment or severe systemic disease. Median age of infection cases was 15 years (3-17 years). Eradication regimen used in all patients combined the use of 3 antibiotics (amoxicillin and metronidazole or clarithromycin) and proton pump inibhitor for 14 days and was tailored according antimicrobial susceptibility. 79.5% of the patients completed the treatment. The resistance rate for metronidazole and clarithromycin was 3.3% and 23.3%, respectively. There was no resistance for amoxicilin and levofloxacin. The rate of genotypic resistance to clarithromycin was 37.2%. The eradication rate was 97.8%.

CONCLUSIONS

The authors found a high resistance rate of H. pylori for clarithromycin in this northern portuguese pediatric center. This factor should determine a change in local current treatment, contraindicating the use of clarithromycin as a first-line treatment for H. pylori infection in children. The high eradication rate maybe explained for the eradication treatment tailored according antimicrobial susceptibility.

Diagnosis and treatment of Helicobacter pylori in the pediatric population

Although about 35 years have elapsed since the discovery of the Helicobacter pylori, its diagnosis and the choice of optimal eradication therapy are still to be defined. Over time, there has been an increase in interest, publications, recommendations and guidelines. Moreover, management of the disease in pediatric subjects differs somewhat to that of adults and requires a more delicate approach leading to alternative strategies for both diagnosis and treatment. Which patient should be investigated for H. pylori, when to perform noninvasive or invasive tests, what are the proper therapeutic options and best antibiotics regimen to eradicate the infection are practices changing with evidences through time. Therefore, an updated guideline was published by the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) in 2017. The aim of this review is to highlight what is new and what differs between adult and pediatric population regarding the management of H. pylori infection after the ESPGHAN/NASPGHAN guidelines, enriched with updates from literature reviews published over the last two years.

When is Helicobacter pylori acquired in populations in developing countries? A birth-cohort study in Bangladeshi children

Helicobacter pylori colonization is prevalent throughout the world, and is predominantly acquired during childhood. In developing countries, >70% of adult populations are colonized with H. pylori and >50% of children become colonized before the age of 10 years. However, the exact timing of acquisition is unknown. We assessed detection of H. pylori acquisition among a birth cohort of 105 children in Mirzapur, Bangladesh. Blood samples collected at time 0 (cord blood), and at 6, 12, 18, and 24 months of life were examined for the presence of IgG and IgA antibodies to whole cell H. pylori antigen and for IgG antibodies to the CagA antigen using specific ELISAs and immunoblotting. Breast milk samples were analyzed for H. pylori-specific IgA antibodies. Cord blood was used to establish maternal colonization status. H. pylori seroprevalence in the mothers was 92.8%. At the end of the two-year follow-up period, 50 (47.6%) of the 105 children were positive for H. pylori in more than one assay. Among the colonized children, CagA prevalence was 78.0%. A total of 58 children seroconverted: 50 children showed persistent colonization and 8 (7.6%) children showed transient seroconversion, but immunoblot analysis suggested that the transient seroconversion observed by ELISA may represent falsely positive results. Acquisition of H. pylori was not influenced by the mother H. pylori status in serum or breastmilk. In this population with high H. pylori prevalence, we confirmed that H. pylori in developing countries is detectable mainly after the first year of life.

Designing a novel ELISA method based on CagA, NapA recombinant antigens to increase sensitivity and specificity of Helicobacter pylori whole cell antigen detection

AIM

In this research, we designed a direct Enzyme Linked Immunoassay method to detect Helicobacter pylori antigens in stool specimens.

BACKGROUND

Helicobacter pylori infection as the worldwide problem is related to many gastrointestinal disorders such as gastritis, gastric cancer, non-ulcer disease, peptic ulcer disease and duodenal ulcer.

METHODS

We produced and purified recombinant CagA and NapA antigens in Escherichia coli and extracted their antibodies from a panel of positive sera specimens. We designed a novel enzyme linked immunoassay direct method in combination with the whole cell for the qualitative and quantitative detection of Helicobacter pylori antigens in human stool. Assay performance was evaluated by histopathology staining and urease activity.

RESULTS

The sensitivity and specificity of assay was determined as 91.7 [95% confidence interval: 89.3-95.6%] and 93.1% [95% CI: 91.2-96.4%], respectively. Novel ELISA exhibits enhanced sensitivity and specificity of Helicobacter pylori detection in comparison with another commercially available kit.

CONCLUSION

Combination of the recombinant antigens and whole cell of Helicobacter pylori in immunoassay designing is a new approach about early diagnosis, treatment and fallowing up of the Helicobacter pylori infected patients, especially in peptic cancer cases.

A one-step immune-chromatographic Helicobacter pylori stool antigen test for children was quick, consistent, reliable and specific

AIM

This French study assessed a quick, noninvasive, immuno-chromatographic, Helicobacter pylori (H. pylori) stool antigen test for detecting infections in children.

METHODS

We enrolled 158 children, with a median age of 8.5 years (range eight months to 17 years), with digestive symptoms suggesting upper gastrointestinal tract disease. Upper digestive endoscopy was performed with gastric biopsy specimens for histology, a rapid urease test, culture test and quantitative real-time polymerase chain reaction. The H. pylori stool antigen test was performed twice for each child and the results were compared to the reference method.

RESULTS

The reference methods showed that 23 (14.6%) of the 158 children tested were H. pylori positive. The H. pylori stool antigen test showed 91.3% sensitivity, with a 95% confidence interval (95% CI) of 86.9-95.6 and 97% specificity (95% CI 94.3-99.6), 30.84 positive likelihood ratio and 0.09 negative likelihood ratio. The test accuracy was 96.2% (95% CI 93.2-99.1). The two blinded independent observers produced identical H. pylori stool antigen test results and the Kappa coefficient for the H. pylori stool antigen test was one.

CONCLUSION

The H. pylori stool antigen test was found to be a consistent, reliable, quick and specific test for detecting the H. pylori infection in children.

Joint ESPGHAN/NASPGHAN Guidelines for the Management of Helicobacter pylori in Children and Adolescents (Update 2016)

BACKGROUND

Because of the changing epidemiology of Helicobacter pylori infection and low efficacy of currently recommended therapies, an update of the European Society for Paediatric Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations for the diagnosis and management of H pylori infection in children and adolescents is required.

METHODS

A systematic review of the literature (time period: 2009-2014) was performed. Representatives of both societies evaluated the quality of evidence using GRADE (Grading of Recommendation Assessment, Development, and Evaluation) to formulate recommendations, which were voted upon and finalized using a Delphi process and face-to-face meeting.

RESULTS

The consensus group recommended that invasive diagnostic testing for H pylori be performed only when treatment will be offered if tests are positive. To reach the aim of a 90% eradication rate with initial therapy, antibiotics should be tailored according to susceptibility testing. Therapy should be administered for 14 days, emphasizing strict adherence. Clarithromycin-containing regimens should be restricted to children infected with susceptible strains. When antibiotic susceptibility profiles are not known, high-dose triple therapy with proton pump inhibitor, amoxicillin, and metronidazole for 14 days or bismuth-based quadruple therapy is recommended. Success of therapy should be monitored after 4 to 8 weeks by reliable noninvasive tests.

CONCLUSIONS

The primary goal of clinical investigation is to identify the cause of upper gastrointestinal symptoms rather than H pylori infection. Therefore, we recommend against a test and treat strategy. Decreasing eradication rates with previously recommended treatments call for changes to first-line therapies and broader availability of culture or molecular-based testing to tailor treatment to the individual child.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Paediatric Rome III Criteria-Related Abdominal Pain Is Associated With Helicobacter pylori and Not With Calprotectin

OBJECTIVES

Abdominal pain-related functional gastrointestinal disorders in children include functional dyspepsia, functional abdominal pain, irritable bowel syndrome, and abdominal migraine. We aimed to evaluate a possible association between functional abdominal pain disorders and Helicobacter pylori infection and faecal calprotectin level.

METHODS

Prospective observational study including consecutive children with functional gastrointestinal disorders fulfilling Rome III criteria (cases) and age/sex-matched healthy controls. H pylori has been detected by biopsy-based tests and stool-antigen detection, faecal calprotectin by enzyme-linked immunosorbent assay.

RESULTS

A total of 56 cases (27 with functional dyspepsia) and 56 controls were enrolled. H pylori being detected in 17 of 56 cases (30.4%) and 4 of 56 controls (7.1%, odds ratio: 5.7; 95% confidence interval [CI]: 1.8-18.2, P = 0.003). H pylori was detected significantly more frequently in cases with functional dyspepsia (14/27, 51.9% odds ratio: 14.0; 95% CI: 3.9-49.7, P = 0.00001) than in controls and not in cases with other well-recognized functional gastrointestinal complaints (3/29, 10.3%). The median faecal calprotectin level was similar in cases (7.8 μg/g, 95% CI: 7.8-8.4) including those with gastritis, and controls (9.1 μg/g, 95% CI: 7.8-11.3). Gastritis features were more frequent in H pylori-infected and noninfected cases with functional dyspepsia (27/27, 100%) than in cases with other abdominal functional complaints (15/29, 51.7%, P = 0.007).

CONCLUSIONS

H pylori gastritis and noninfectious gastritis were associated with functional dyspepsia in children referred for abdominal pain-related functional gastrointestinal disorders while faecal calprotectin is not a predictor of gastritis and is similar in children with functional abdominal pain symptoms and in controls.

Updates on the Diagnosis of Helicobacter pylori Infection in Children: What Are the Differences between Adults and Children?

Helicobacter pylori infection is acquired mainly during childhood and causes various diseases such as gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and iron deficiency anemia. Although H. pylori infection in children differs from adults in many ways, this is often overlooked in clinical practice. Unlike adults, nodular gastritis may be a pathognomonic endoscopic finding of childhood H. pylori infection. Histopathological findings of gastric tissues are also different in children due to predominance of lymphocytes and plasma cells and the formation of gastric MALT. Although endoscopy is recommended for the initial diagnosis of H. pylori infection, several non-invasive diagnostic tests such as the urea breath test (UBT) and the H. pylori stool antigen test (HpSA) are available and well validated even in children. According to recent data, both the (13)C-UBT and HpSA using enzyme-linked immunosorbent assay are reliable non-invasive tests to determine H. pylori status after eradication therapy, although children younger than 6 years are known to have high false positives. When invasive or noninvasive tests are applied to children to detect H. pylori infection, it should be noted that there are differences between children and adults in diagnosing H. pylori infection.

Diagnostic accuracy of three monoclonal stool tests in a large series of untreated Helicobacter pylori infected patients

OBJECTIVES

Immunochromatographic tests need to be improved in order to enhance their reliability. Recently, several new kits have appeared on the market. The objective was to evaluate the diagnostic accuracy of three monoclonal rapid stool tests - the new Uni-Gold™ H.pylori Antigen (Trinity Biotech, Ireland), the RAPID Hp StAR (Oxoid Ltd., UK) and the ImmunoCard STAT! HpSA (Meridian Diagnostics, USA) - for detecting H. pylori infection prior to eradication treatment.

DESIGN AND METHODS

Diagnostic accuracy (sensitivity and specificity) and reliability (concordance between observers) were evaluated in 250 untreated consecutive dyspeptic patients. The gold standard for diagnosing H. pylori infection was defined as the concordance of two or more of rapid urease test (RUT), histopathology and urease breath test (UBT) or positive culture in isolation. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated. Sensitivity and specificity were compared using the McNemar test.

RESULTS

The three tests showed a good correlation, with Kappa values>0.9. RAPID Hp StAR had a sensitivity of 91%-92% and a specificity ranging from 77% to 85%. Its sensitivity was higher than that of Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA (p<0.01). Uni-Gold™ H.pylori Antigen kit showed a sensitivity of 83%, similar to ImmunoCard STAT! HpSA. Specificity of Uni-Gold™ H.pylori Antigen approached 90% (87-89%) and was superior to that of RAPID Hp StAR (p<0.01).

CONCLUSIONS

Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA present similar levels of diagnostic accuracy. RAPID Hp StAR was the most sensitive but less reliable of the three immunochromatographic stool tests. None are as accurate and reliable as UBT, RUT and histology.

On the importance of developing a new generation of breath tests for Helicobacter pylori detection

State-of-the-art methods for non-invasive detection of the Helicobacter pylori (H. pylori) infection have been considered. A reported global tendency towards a non-decreasing prevalence of H. pylori worldwide could be co-influenced by the functional limitations of urea breath tests (UBTs), currently preferred for the non-invasive recognition of H. pylori in a clinical setting. Namely, the UBTs can demonstrate false-positive or false-negative results. Within this context, limitations of conventional clinically exploited H. pylori tests have been discussed to justify the existing need for the development of a new generation of breath tests for the detection of H. pylori and the differentiation of pathogenic and non-pathogenic strains of the bacterium. This paper presents the results of a pilot clinical study aimed at evaluating the development and diagnostic potential of a new method based on the detection of the non-urease products of H. pylori vital activity in exhaled gas. The characteristics of breath of adolescents with H. pylori-positive and H. pylori-negative functional dyspepsia, together with a consideration of the cytotoxin-associated gene A (CagA) status of H. pylori-positive subjects, have been determined for the first time using innovative point-contact nanosensor devices based on salts of the organic conductor tetracyanoquinodimethane (TCNQ). The clinical and diagnostic relevance of the response curves of the point-contact sensors was assessed. It was found that the recovery time of the point-contact sensors has a diagnostic value for differentiation of the H. pylori-associated peptic ulcer disease. The diagnostically significant elongation of the recovery time was even more pronounced in patients infected with CagA-positive H. pylori strains compared to the CagA-negative patients. Taking into account the operation of the point-contact sensors in the real-time mode, the obtained results are essential prerequisites for the development of a fast and portable breath test for non-invasive detection of cytotoxic CagA strains of H. pylori infection. The relaxation time of the point-contact nanosensors could be selected as a diagnostic criterion for non-invasive determination of H. pylori-associated destructive lesions of the gastroduodenal area in adolescents, using the point-contact spectroscopic concept of breath analysis. This can subsequently be implemented into a 'test-and-treat' approach for the management of uninvestigated dyspepsia in populations with a high prevalence of H. pylori (according to the Maastricht III and IV Consensus recommendations).

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Loop-Mediated Isothermal Amplification as a Fast Noninvasive Method of Helicobacter pylori Diagnosis

BACKGROUND

Helicobacter pylori infection is etiologically associated with some important health problems such as gastric cancer. Because of the high clinical importance of H. pylori infection, development of a noninvasive test for the detection of H. pylori is desirable.

METHODS

In this study, a loop-mediated isothermal amplification (LAMP) targeted ureC of H. pylori was evaluated on 100 stool specimens and compared with a stool antigen test. Culture and rapid urease test were considered as gold standards.

RESULTS

The overall detection rate of the fecal antigen test and LAMP was 58% and 82%, respectively. The analytical sensitivity of the fecal antigen test and LAMP was 500 and 10 H. pylori cells/g and 10 fg DNA/reaction, which is equal to six H. pylori genome.

CONCLUSION

LAMP technique has been characterized by high sensitivity and low detection limit for the detection of H. pylori in stool specimen. Clinical diagnostic performance of LAMP was better than the stool antigen test.

Evaluation of methods for H. pylori detection in PPI consumption using culture, rapid urease test and smear examination

BACKGROUND

Culture, rapid urease test (RUT) and smear examination have been used as reliable methods for diagnosis of H. pylori infection. Accurate performance of these tests requires good quality biopsies with considerable number of bacterial cells. However, consumption of proton pump inhibitors (PPIs) affects growth and urease activity of H. pylori, leading to false negative results. In this study the efficacy of culture, RUT and smear examination was assessed and the effect of PPI consumption was evaluated.

METHODS

Two antral biopsies from 530 dyspeptic patients with and without PPI consumption were used for RUT, culture and smear examination. Statistical analysis was used to determine the association between results of culture, RUT or smear examination and PPI consumption. Sensitivity and specificity of three tests were calculated by standard methods.

RESULTS

H. pylori infection was detected in 40% of patients by culture, 48.3% by RUT and 21.1% by smear examination and the overall detection rate was 54%. A strong correlation was found between PPI consumption and negative results of culture and RUT (P<0.05) but not smear examination. The sensitivity of RUT was reduced as a result of PPI consumption. This reduction was more profound in 1-hr RUT (92.2% to 74.4%) compared with 24-hr RUT (93.9% to 81.6%).

CONCLUSIONS

Prevalence of H. pylori was declined, compared with previous studies. This decrement could be due to false negative results of H. pylori diagnostic tests, among which culture and RUT are mostly affected by PPI. Accordingly, PPI consumption should be stopped before performance of endoscopy.

Evaluation of a stool antigen test using a mAb for native catalase for diagnosis of Helicobacter pylori infection in children and adults

Non-invasive diagnosis of Helicobacter pylori infection is important not only for screening of infection but also for epidemiological studies. Stool antigen tests are non-invasive and are convenient to identify H. pylori infection, particularly in children. We evaluated the stool antigen test, which uses a mAb for native catalase of H. pylori developed in Japan. A total of 151 stool samples were collected from participants (52 children and 99 adults) of the Sasayama Cohort Study and stored between -30 and -80 °C. The stool antigen test used was Testmate pylori antigen (TPAg), and was performed according to the manufacturer's instructions. Furthermore, we conducted a quantitative real-time PCR test and compared the PCR results with those of the TPAg test. When compared with the results in real-time PCR, the sensitivity of TPAg was 89.5 % overall, 82.7 % for children and 92.4 % for adults, and the specificity was 100 %. The accuracy was 93.4 % overall, 90.4 % for children and 94.9 % for adults, and there was no significant difference in the accuracy of TPAg between children and adults. Five of 28 children (18 %) and five of 38 adults (13 %) were PCR positive with negative TPAg results. Four of five children with positive PCR and negative TPAg results were given a (13)C-urea breath test and all four children tested negative. No significant correlation was observed between the TPAg results and DNA numbers of H. pylori in faeces among children or adults. A stool antigen test (TPAg) using a mAb for native catalase is useful for diagnosis of H. pylori in children and adults. Additionally, this test has particularly high specificity.

Accuracy of stool antigen test for the diagnosis of Helicobacter pylori infection in children: a meta-analysis

INTRODUCTION

Helicobacter pylori (H. pylori) is regarded as a major pathogen in gastrointestinal diseases and the infection rate is still at a high level in children. Therefore, the diagnosis is of great clinical importance. The objective was to perform a meta-analysis on H. pylori stool antigen test (SAT) for the diagnosis of the infection in children.

METHODS

Published information on the sensitivity and specificity of stool antigen test in each study was collected to assess the accuracy of the test for the diagnosis of H. pylori infection. Forty-five eligible studies were selected for analysis. Data on the publication year, H. pylori prevalence, eradication rate and gold standard of each study were summarized.

RESULT

Forty-five studies, including 5931 patients, evaluated the accurancy of H. pylori SAT. Pooled sensitivity, specificity, LR+ and LR- were: 92.1%, 94.1%, 17.01, 0.085, respectively. Subgroup analyses were conducted to evaluate the sensitivity and specificity of H. pylori SAT in different situations and found that sensitivity and specificity were significantly higher when monoclonal H. pylori SAT and two or more reference methods were used.

CONCLUSIONS

Detection of H. pylori antigen in stools with ELISA monoclonal antibodies is a non-invasive efficient test for the diagnosis of infection in children. However, the available one-step and polyclonal SAT tests are still unreliable.

Helicobacter pylori infection in pregnant women in four districts of Uganda: role of geographic location, education and water sources

BACKGROUND

The prevalence of Helicobacter pylori infection varies in relation to geography, ethnicity and socioeconomic factors. Available data on the prevalence of Helicobacter pylori infection in Uganda are not representative of the general population. We sought to describe the epidemiology of this infection in pregnant women in Uganda to provide background data for a study into the effect of H. pylori infection during pregnancy on the hematological response to iron supplementation.

METHODS

Using a cross-sectional design, H. pylori infection was assessed by the stool antigen test among 447 pregnant women attending antenatal care clinics in Apac, Mbale, Mbarara and Rakai Districts which are in different geographical regions in Uganda, and at Kawempe Health Center which serves a low-income densely populated area in Kampala City. Socio-demographic and household data were collected by face-to-face interviews using a questionnaire. Associations between H. pylori infection and socio-demographic and household characteristics were analyzed using logistic regression.

RESULTS

The overall prevalence of H. pylori infection was 45.2% but varied by geographical location from 18.2% in Apac District to 60.5% at Kawempe Health Centre. At 18.4%, the Langi ethnic group, who were enrolled exclusively in Apac District, had the lowest prevalence of H. pylori infection while the Gisu had the highest prevalence (58.4%). H. pylori was independently associated with enrollment at clinics not in Apac (adjusted OR = 5.68; 95% CI: 3.02-10.7) and with using water from public wells, boreholes or springs (AOR = 3.20; 95% CI: 1.19-8.61) and from rivers, lakes or streams (AOR = 5.20; 95% CI: 1.58-17.05). Urban residence (AOR = 1.71; 95% CI: 1.13-2.60) and no formal education (AOR = 1.95; 95% CI: 1.03-3.67) were also independently associated with H. pylori infection.

CONCLUSIONS

The unexpected variation in the prevalence of H. pylori infection in Uganda calls for population-based studies in the region and offers an opportunity to study the transmission dynamics of H. pylori infection. The association between H. pylori infection and surface water sources for household use suggests waterborne transmission of H. pylori infection highlighting the need for concerted efforts in environmental health in communities and at the household level.

Management of Helicobacter pylori infection in Latin America: a Delphi technique-based consensus

AIM

To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.

METHODS

Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.

RESULTS

A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing.

CONCLUSION

These achievable steps toward better region-specific management can be expected to improve clinical health outcomes.

A review of Helicobacter pylori diagnosis, treatment, and methods to detect eradication

Helicobacter pylori (H. pylori) affects nearly half of the world’s population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient’s clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.

Stool antigen tests for the management of Helicobacter pylori infection

Stool antigen tests (SATs) are noninvasive diagnostic modules for Helicobacter pylori (H. pylori) infection. Two types of SATs exist for the diagnosis of H. pylori infection, one based on enzyme immunoassay (EIA) and another on immunochromatography (ICA). SATs do not require expensive chemical agents or specified equipment; hence, they are less expensive compared with the urea breath test. Both European and Japanese guidelines have shown that EIA-based SATs using monoclonal antibodies are useful for primary diagnosis as well as for the assessment of eradication therapy. ICA-based tests do not require particular equipment and are therefore useful in developing countries. SATs are also useful for the diagnosis of H. pylori infection in children and post gastric surgery patients. SATs performed via EIA can assess H. pylori infection in a large number of subjects, almost as well as serology. Thus, SATs would be useful or detecting current infection in such a survey to identify and eradicate H. pylori infection. The accuracy of SATs is lower when the stool samples are unformed or watery, because H. pylori-specific antigens in the stool samples are diluted. Temperature and the interval between stool sample collection and measurement also affect the results of SATs. The choice of test kit depends on the sensitivity and specificity in each region and the circumstances of each patient.

High circulating VEGF level predicts poor overall survival in lung cancer

PURPOSE

Vascular endothelial growth factor (VEGF) is considered as the best-validated key regulator of angiogenesis, while the prognostic role of circulating VEGF in lung cancer remains controversial. We conducted a meta-analysis to evaluate the prognostic role of circulating VEGF.

METHODS

Nineteen studies with a total number of 2,890 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) were used to quantify the predictive ability of circulating VEGF on survival.

RESULTS

The pooled HR of all 17 studies evaluating overall survival (OS) was 1.29 (95 % CI 1.19-1.40, p < 0.001), indicating high circulating VEGF predicted poor OS. When grouped by disease stages, the pooled HRs were 0.97 (95 % CI 0.47-1.47, p < 0.001) for operable stage and 1.34 (95 % CI 1.18-1.49, p < 0.001) for inoperable stage. The pooled HRs were 1.28 (95 % CI 1.15-1.42, p < 0.001) for serum and 1.31 (95 % CI 1.13-1.49, p < 0.001) for plasma, when categorized by blood sample. Meta-analysis of circulating VEGF related to progression-free survival (PFS) was performed in 7 studies, and the pooled HR was 1.03 (95 % CI 0.96-1.09).

CONCLUSIONS

Our results indicate that high level of circulating VEGF predicts poor OS in lung cancer, yet it does not predict poor PFS.

Helicobacter pylori in pediatrics

This review summarizes important pediatric studies published from April 2011 up to March 2012. Proteomics profile of ulcerogenic Helicobacter pylori strains was defined in the most interesting study of the last year. The antigen stool test is becoming the "gold standard" in prevalence studies, and according to the last epidemiologic studies, the prevalence of H. pylori infection in childhood is not decreasing any more in the developed world. The resistance rate of H. pylori strains is high in children. Therefore, among other important issues concerning H. pylori in pediatrics, guidelines published by ESPGHAN and NASPGHAN last year also recommended culture and susceptibility testing before first-line treatment in areas with high or unknown antibiotic resistance rates.