Stool antigen detection versus 13C-urea breath test for non-invasive diagnosis of pediatric Helicobacter pylori infection in a limited resource setting

Population- and Gender-Based Investigation for Prevalence of Helicobacter pylori in Dhamar, Yemen

Among 35 species of genus Helicobacter, H. pylori is the most common causative agent of human gastritis, peptic ulcer, and gastric cancer. The infection can spread through direct human-to-human contact, fecal-oral route, and contaminated water. The study was designed to investigate the rate of prevalence of H. pylori in the population of Dhamar, Yemen. In this one-year study, 460 including 250 male and 210 female stool specimens were collected between January to December 2020 in Dhamar Governorate, Yemen. Of the total 460, 215 rural (male: n = 120 and female: n = 95) and 245 urban (male: n = 130 and female: n = 115) specimens were investigated for identification of H. pylori by serological test using Helicobacter pylori stool antigen (HpSA) test. In addition, for comparing an improved recovery of H. pylori, conventional culture-based isolation was also carried out using three selective media. Modified Campy-blood Agar (MCA), Belo Horizonte Agar (BHA), and Egg yolk Emulsion (EYE) medium supplemented with antimicrobial agents including vancomycin (10 mg/L), cefsulodin (5 mg/L), trimethoprim (5 mg/L), and amphotericin B (5 mg/L) and isolates were phenotypically characterized. The HpSA test results revealed that of the total 460 specimens, 89 (19.3%) were positive for H. pylori with relatively low in male (n = 43; 17.2%) as compared to the female (n = 46; 21.9%) specimens. After 3-10 days of incubation, H. pylori was recovered at a variable rate on each selective (MCA: 16.5%; BHA: 15.0%; EYE: 13.0%) media. However, culture-based assay results showed less recovery (n = 81; 17.6%) with no significant difference among all selective media tested and between genders (male: n = 39; 15.6%; female: n = 42; 20.0%). The infection rate was comparatively higher in rural (n = 45; 20.9%) as compared to urban (n = 36; 14.7%) population. Overall, the study data showed the prevalence of infection in both genders of all age groups. The present study showed a relatively high rate of infection of H. pylori in the Dhamar population. The serological identification and culture-based methods are important for rapid detection, aid in treatment, and developing policies for the control and eradication of H. pylori infection and to prevent the disease in different age groups in Yemen.

Correlation analysis of gastric mucosal lesions with Helicobacter pylori infection and its virulence genotype in Guiyang, Guizhou province, China

Background

Helicobacter Pylori (H. pylori) infection is the most important factor affecting clinical outcome in patients with gastric mucosal lesions. This study aimed to investigate H. pylori infection in patients with gastric mucosal lesions and their virulence genotype in Guiyang, China.

Methods

Pathological examinations of 1,364 biopsies from patients with upper gastrointestinal symptoms and H. pylori infection were analyzed according to different pathological types. The bacterial genome DNA was extracted from H. pylori strains isolated from gastric biopsies, and the cagA, vacA, and iceA virulence genes were detected and typed to analyze the correlation of their genotypes between different pathological lesions.

Results

The positive rate of H. pylori infection was approximately 19.9% (272/1,364), as determined by histopathological examination (HPE). It was more frequently detected in men than in women. A total of 85 H. pylori isolates were obtained from 280 clinical samples (positive rate 30.4%, 85/280). Of these 85 strains, cagA, vacA, and iceA genes were identified in 85.9%, 100%, and 83.5% of samples, respectively. Approximately 74.1% of strains were cagA East Asian type (cagA-ABD), and 11.8% of were cagA Western strains (cagA-AB, cagA-ABC), only present in patients with chronic non-atrophic gastritis. Gastric intraepithelial neoplasia and gastric cancer harbored both Asian strains. A total of 7 combinations of vacA genotypes were noted, among which s1c/m1b (30.6%) and s1c/m2 (41.2%) were the dominant genotypes. The predominant iceA genotype was iceA1 (64.7%).

Conclusions

We observed that the positive rate of H. pylori infection was related to the pathological type of patients' gastric mucosal lesions. Isolated H. pylori strains showed a unique genotype, mainly East Asian type cagA (ABD), vacA s1c/m2 genotype, and iceA1. These results provide an important reference for further studies of H. pylori in Guizhou province, China.

Systematic Review and Meta-Analysis on the Sensitivity and Specificity of 13C/14C-Urea Breath Tests in the Diagnosis of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) continues to be a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. The aim of the present systematic review and meta-analysis was to determine the sensitivity and specificity of 13C/14C-urea breath tests in the diagnosis of H. pylori infection. A PRISMA systematic search appraisal and meta-analysis were conducted. A systematic literature search of PubMed, Web of Science, EMBASE, Scopus, and Google Scholar was conducted up to August 2022. Generic, methodological and statistical data were extracted from the eligible studies, which reported the sensitivity and specificity of 13C/14C-urea breath tests in the diagnosis of H. pylori infection. A random effect meta-analysis was conducted on crude sensitivity and specificity of 13C/14C-urea breath test rates. Heterogeneity was assessed by Cochran’s Q and I2 tests. The literature search yielded a total of 5267 studies. Of them, 41 articles were included in the final analysis, with a sample size ranging from 50 to 21857. The sensitivity and specificity of 13C/14C-urea breath tests in the diagnosis of H. pylori infection ranged between 64−100% and 60.5−100%, respectively. The current meta-analysis showed that the sensitivity points of estimate were 92.5% and 87.6%, according to the fixed and random models, respectively. In addition, the specificity points of estimate were 89.9% and 84.8%, according to the fixed and random models, respectively. There was high heterogeneity among the studies (I2 = 98.128 and 98.516 for the sensitivity and specificity, respectively, p-value < 0.001). The 13C/14C-urea breath tests are highly sensitive and specific for the diagnosis of H. pylori infection.

Traditional and Modern Diagnostic Approaches in Diagnosing Pediatric Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is the most common bacterial infection worldwide, is usually acquired during childhood and is related to gastric carcinogenesis during adulthood. Therefore, its early proper diagnosis and subsequent successful eradication represent the cornerstones of gastric cancer prevention. The aim of this narrative review was to assess traditional and modern diagnostic methods in terms of H. pylori diagnosis. Several invasive and non-invasive methods were described, each with its pros and cons. The invasive diagnostic methods comprise endoscopy with biopsy, rapid urease tests, histopathological exams, cultures and biopsy-based molecular tests. Among these, probably the most available, accurate and cost-effective test remains histology, albeit molecular tests definitely remain the most accurate despite their high costs. The non-invasive tests consist of urea breath tests, serology, stool antigens and non-invasive molecular tests. Urea breath tests and stool antigens are the most useful in clinical practice both for the diagnosis of H. pylori infection and for monitoring the eradication of this infection after therapy. The challenges related to accurate diagnosis lead to a choice that must be based on H. pylori virulence, environmental factors and host peculiarities.

Detection of Helicobacter Pylori infection by invasive and non-invasive techniques in patients with gastrointestinal diseases from Iraq: A validation study

There is still no agreement on the gold standard technique for diagnosing of H. Pylori in Iraq, as well as a paucity of data on the validity of different diagnostic techniques. This study aimed to investigate the prevalence of this bacterium with different methods and compare them to the quantitative polymerase chain reaction (qPCR) as a golden standard technique among Iraqi patients. In total, 115 Iraqi patients strongly suspected of H. pylori infection were enrolled in the current study. Invasive techniques including rapid urease testing (RUT) and gastric tissue culture in addition to non-invasive techniques including 14C-Urea breath test (14C-UBT), stool antigen test (SAT), CagA-IgG serology, and qPCR were performed to confirm the H. pylori infection. The qPCR was used as the gold standard to estimate the sensitivity, specificity, positive and negative predictive values for the studied diagnostic tests. Overall, the prevalence rate of H. pylori in Iraqi patients was ranged from 47.8 to 70.4% using different methods. The positive results for each test were as follows: qPCR 81, (70.4%) UBT 79 (68.7%), SAT 77 (67%), RUT 76 (66.1%), Cag-IgG 61 (53%), and culture 55 (47.8%). The 14C-UBT showed the highest overall performance with 97.5% sensitivity, 97% specificity, and total accuracy of 97.3% followed by SAT, RUT, Cag-IgG, and culture method. Based on the accuracy of the studied methods for H. pylori detection, they can be arranged in order as follows: qPCR > UBT > SAT > RUT> CagA IgG > culture. Since a universal gold standard assay for the diagnosis of H. pylori has not yet been established in Iraq, the UBT may be recommended as first choice due to its higher performance compared to other methods.

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.

Current Helicobacter pylori Diagnostics

The high prevalence of Helicobacter pylori and the variety of gastroduodenal diseases caused by this pathogen necessitate the use of only accurate methods both for the primary diagnosis and for monitoring the eradication effectiveness. There is a broad spectrum of diagnostic methods available for detecting H. pylori. All methods can be classified as invasive or non-invasive. The need for upper endoscopy, different clinical circumstances, sensitivity and specificity, and accessibility defines the method chosen. This article reviews the advantages and disadvantages of the current options and novel developments in diagnostic tests for H. pylori detection. The progress in endoscopic modalities has made it possible not only to diagnose precancerous lesions and early gastric cancer but also to predict H. pylori infection in real time. The contribution of novel endoscopic evaluation technologies in the diagnosis of H. pylori such as visual endoscopy using blue laser imaging (BLI), linked color imaging (LCI), and magnifying endoscopy is discussed. Recent studies have demonstrated the capability of artificial intelligence to predict H. pylori status based on endoscopic images. Non-invasive diagnostic tests such as the urea breathing test and stool antigen test are recommended for primary diagnosis of H. pylori infection. Serology can be used for initial screening and epidemiological studies. The histology showed its value in detecting H. pylori and provided more information about the degree of gastric mucosa inflammation and precancerous lesions. Molecular methods are mainly used in detecting antibiotic resistance of H. pylori. Cultures from gastric biopsies are the gold standard and recommended for antibiotic susceptibility tests.

Management of Helicobacter pylori infection: The Bhubaneswar Consensus Report of the Indian Society of Gastroenterology

The Indian Society of Gastroenterology (ISG) felt the need to organize a consensus on Helicobacter pylori (H. pylori) infection and to update the current management of H. pylori infection; hence, ISG constituted the ISG's Task Force on Helicobacter pylori. The Task Force on H. pylori undertook an exercise to produce consensus statements on H. pylori infection. Twenty-five experts from different parts of India, including gastroenterologists, pathologists, surgeons, epidemiologists, pediatricians, and microbiologists participated in the meeting. The participants were allocated to one of following sections for the meeting: Epidemiology of H. pylori infection in India and H. pylori associated conditions; diagnosis; treatment and retreatment; H. pylori and gastric cancer, and H. pylori prevention/public health. Each group reviewed all published literature on H. pylori infection with special reference to the Indian scenario and prepared appropriate statements on different aspects for voting and consensus development. This consensus, which was produced through a modified Delphi process including two rounds of face-to-face meetings, reflects our current understanding and recommendations for the diagnosis and management of H. pylori infection. These consensus should serve as a reference for not only guiding treatment of H. pylori infection but also to guide future research on the subject.

Noninvasive Helicobacter pylori Diagnostic Methods in Indonesia

Although the prevalence of Helicobacter pylori infection in Indonesia is lower than that in other countries, H. pylori is still an essential pathogen associated with severe gastric mucosal damage and dyspeptic symptoms. Invasive diagnostic methods are not ideal due to the lack of endoscopic centers and high costs without full coverage by social insurance. Among the noninvasive methods, the urea breath test is widely available in Indonesia and has been suggested as the primary option to ensure the successful eradication of H. pylori. There has been no local validation for the urea breath test utilizing ¹³C or ¹⁴C. The stool antigen test is inexpensive and suitable for use in active infections before and after eradication; however, customs and habits are obstacles to delivering fresh stool on time. Only polyclonal antibodies and qualitative stool antigen test kits with low sensitivity are available. Serology is a widely validated method and has good accuracy, but it cannot distinguish between active and inactive infections. According to our observations, serology is the main choice of experts and patients, as it is simple, inexpensive and widely known. The urine test is an alternative for reducing costs and endoscopic workload, with high accuracy but low sensitivity. Further studies are necessary to prove the validity of the urine test to be used throughout Indonesia, especially in areas with a low prevalence of H. pylori infection. In conclusion, the validated urea breath test and the stool antigen test are considered noninvasive practical approaches for the detection of H. pylori infection in Indonesia, with serological and urine tests as alternatives.

Six decades of lateral flow immunoassay: from determining metabolic markers to diagnosing COVID-19

Technologies based on lateral flow immunoassay (LFIA), known in some countries of the world as immunochromatographic tests, have been successfully used for the last six decades in diagnostics of many diseases and conditions as they allow rapid detection of molecular ligands in biosubstrates. The popularity of these diagnostic platforms is constantly increasing in healthcare facilities, particularly those facing limited budgets and time, as well as in household use for individual health monitoring. The advantages of these low-cost devices over modern laboratory-based analyzers come from their availability, opportunity of rapid detection, and ease of use. The attractiveness of these portable diagnostic tools is associated primarily with their high analytical sensitivity and specificity, as well as with the easy visual readout of results. These qualities explain the growing popularity of LFIA in developing countries, when applied at small hospitals, in emergency situations where screening and monitoring health condition is crucially important, and as well as for self-testing of patients. These tools have passed the test of time, and now LFIA test systems are fully consistent with the world's modern concept of ‘point-of-care testing’, finding a wide range of applications not only in human medicine, but also in ecology, veterinary medicine, and agriculture. The extensive opportunities provided by LFIA contribute to the continuous development and improvement of this technology and to the creation of new-generation formats. This review will highlight the modern principles of design of the most widely used formats of test-systems for clinical laboratory diagnostics, summarize the main advantages and disadvantages of the method, as well as the current achievements and prospects of the LFIA technology. The latest innovations are aimed at improving the analytical performance of LFIA platforms for the diagnosis of bacterial and viral infections, including COVID-19.

STOOL ANTIGEN (HPSA) TEST IN DETECTION OF HELICOBACTER PYLORI INFECTION AMONG ADULT DYSPEPTIC PATIENTS IN TRIPOLI, LIBYA

Background. Helicobacter pylori is the most common infection in the world. Relationship between H. pylori and dyspepsia was confirmed by many studies, it has been strongly associated with peptic ulcer disease and gastric cancer. In that respect, several invasive and noninvasive methods for the diagnosis of H. pylori infection were utilized. Objective. The aim of the study was to evaluate the association between dyspepsia and the positivity of H. pylori stool antigen test, to compare this test with serological IgG test. Methods. 125 adult patients were randomly selected from gastroenterology units of Mediterranean and Tajurah clinics in Tripoli. Stool samples were taken for detection of H. pylori antigen by enzyme immunoassay. Blood samples for detection of anti-H. pylori IgG antibodies were taken. Data were statistically analyzed using SPSS. Results. 125 dyspeptic patients: 47 male and 78 female, aged 18-83 years old were examined. 80 patients were infected by H. pylori that was proved by a positive stool test, 88 had a positive IgG test. The prevalence was higher in the patients aged 28-47 years old. There was substantial relation to age, marital status and economic risk factors; there was no association between H. pylori and gender, sources of drinking water, living standards, smoking, family history of peptic ulcer, drug consumption, and blood groups. Conclusions. Relatively high rates of detection by HpSA prove that stool testing might be a reliable, simple, inexpensive, and non-invasive alternative test ащк detectшщт of H. pylori, diagnosing active infection and confirming cure. However IgG test has a low sensitivity, specificity, and accuracy compare to the HpSA test. Thus it can be used for screening purposes.

First national survey of the diagnosis of Helicobacter pylori infection in Clinical Microbiology Laboratories in Spain

INTRODUCTION

The aim of this study was to know, through a national survey, the methods and techniques used for the diagnosis of Helicobacter pylori (Hp) in the different Clinical Microbiology Services/Laboratories in Spain, as well as antibiotic resistance data.

METHODS

The survey requested information about the diagnostic methods performed for Hp detection in Clinical Microbiology laboratories, including serology, stool antigen, culture from gastric biopsies, and PCR. In addition, the performance of antibiotic susceptibility was collected. Data on the number of samples processed in 2016, positivity of each technique and resistance data were requested. The survey was sent by email (October-December 2017) to the heads of 198 Clinical Microbiology Laboratories in Spain.

RESULTS

Overall, 51 centers from 29 regions answered the survey and 48/51 provided Hp microbiological diagnostic testing. Concerning the microbiological methods used to diagnose Hp infection, the culture of gastric biopsies was the most frequent (37/48), followed by stool antigen detection (35/48), serology (19/48) and biopsy PCR (5/48). Regarding antibiotic resistance, high resistance rates were observed, especially in metronidazole and clarithromycin (over 33%).

CONCLUSION

Culture of gastric biopsies was the most frequent method for detection of Hp, but the immunochromatographic stool antigen test was the one with which the largest number of samples were analyzed. Nowadays, in Spain, it concerns the problem of increased antibiotic resistance to 'first-line' antibiotics.

Diagnosis of Helicobacter pylori infection in clinical practice

Diagnostic tests used to detection Helicobacter pylori are divided into invasive (requiring endoscopy) and non-invasive, direct (bacteriological, histological or molecular detection of the bacterium) and indirect (detection of urease activity of the bacterium or antibodies to it). The choice of the test is determined by the clinical situation, as well as by its availability and cost. The sensitivity of most tests is affected by the use of antisecretory drugs and antibiotics.

Diagnosis of Helicobacter pylori infection

The progress this year in Helicobacter pylori diagnosis concerned essentially endoscopy and molecular techniques. New endoscopy techniques such as blue laser imaging and magnifying narrow band imaging allow the visualization of mucosal aspects representing H. pylori infection, intestinal metaplasia, and even ambiguous early gastric cancer. Several real-time PCRs have also been used either to quantify H. pylori or to detect mutations associated with clarithromycin resistance in gastric biopsies or applied on gastric juice, stool specimens, or the oral cavity. The presence of H. pylori in free-living amebae purified from wastewater and drinking water was also determined by PCR and sequencing, as well as culture from a few wastewater samples. Among the noninvasive methods, the urea breath test was used in different conditions, including with a new test meal, which is claimed to avoid the proton-pump inhibitor washout period before testing. Several articles concerning antibody detection and stool antigen test were also published.

Helicobacter pylori and some aspects of gut microbiota in children

Helicobacter pylori infection in children differs from infection in adults in many aspects. The rate of infection, epidemiology, clinical presentations and complications, the applicability of diagnostic tests, antibiotic resistance, treatment options, and success rates differ significantly. Due to all these differences, management guidelines for children and adults differ also substantially. In 2017, the Updated ESPGHAN and NASPGHAN Guidelines on the management of H. pylori infection in children were published, emphasizing the differences in clinical presentation and indications for treatment, stating that the primary goal of clinical investigation in children is to identify the cause of upper gastrointestinal symptoms rather than the presence of H. pylori infection. Therefore, the diagnosis should be based on upper endoscopy, and the "test and treat strategy" should not be used in children. Due to an increasing rate of antibiotic resistance worldwide, the updated guidelines recommend broader use of antimicrobial susceptibility testing for H. pylori strains in order to tailor eradication treatment accordingly. Moreover, treatment in children should be prescribed only when indicated and should be based on the rate of eradication in local populations aiming for treatment success above 90%. During the last two decades there has been a steady decrease in the rate of H. pylori infection in both children and adults in the Western world. Two recent publications studying the incidence of H. pylori infection confirmed that early childhood is a time for acquisition of infection both in industrialized and nonindustrialized countries. In addition, they showed that H. pylori could be acquired outside the family. In respect to the inverse association between H. pylori and allergy, a longitudinal study demonstrated that early exposure to H. pylori at any age was inversely associated with atopy and allergic conditions.

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.