Evaluation of three different tests for the detection of stool antigens to diagnose Helicobacter pylori infection in patients with upper gastrointestinal bleeding.

Background and objectives: Several diagnostic assays are used for the detection of Helicobacter pylori infection in suspected peptic ulcer cases. H. pylori stool antigen test is a non-invasive method for the detection of active infection. The present study has evaluated the efficacy of rapid stool antigen test to diagnose H. pylori infection in patients with dyspepsia.Materials and methods: Adult patients with complains of dyspepsia attending the Department of Gastroenterology, Hepatobiliary and Pancreatic Diseases (GHPD) of BIRDEM hospital for endoscopy were included. Gastric biopsy, blood and stool samples were obtained from each participant after informed written consent. Rapid urease test (RUT), serum H. pylori immunoglobulin A (IgA) and IgG and rapid H. pylori stool antigen (HpSAg) tests were performed. Only stool samples were obtained from 31 neonates aged 1 to 30 days as negative control for HpSAg test.Results: A total of 91 adult patients with complain of dyspepsia were included in the study. Out of 91 cases, 17 (18.7%) and 74 (81.3%) had peptic ulcer and erosion respectively. HpSAg was positive in 63.7% cases compared to 42.9% and 62.6% respectively by RUT and IgA. The rate of HpSAg positivity was significantly higher (p<0.05) in ulcer compared to erosion cases. HpSAg test was positive in all (100%) RUT positive cases. Combination of HpSAg test and IgA yielded highest positive result in both ulcer (82.4%) and erosion (84%) cases. H. pylori IgG was positive in all cases.Conclusion: The study has demonstrated that HpSAg test is an effective and non-invasive diagnostic tool to detect active H. pylori infection in suspected dyspeptic patients.IMC J Med Sci 2016; 10(2): 39-44

To evaluate the accuracy of Helicobacter pylori (Hp) stool antigen test for diagnosing Hp infection. Articles related to diagnosis of Hp infection by Hp stool antigen test, published before March 2004, were retrieved in the databanks such as CBMdisc, CMCC, CNKI, and VIP. Related journals were searched manually. Meta-analysis was performed by SROC curve recommended by Diagnostic and Screening Group of the Cochrane Collaboration Web with the parameters such as sensitivity, specificity, accuracy, predictive values, and likelihood ratio. In total 19 studies including 3123 patients met the inclusion criteria. The sensitivity of Hp stool antigen for the diagnosis of Hp infection was 94% and its specificity was 93%. Helicobacter pylori stool antigen examination is a simple, noninvasive and highly accurate method in diagnosis of Hp infection.

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

Background: Helicobacter pylori colonize the human stomach and is associated with gastritis, gastric and duodenal ulcers, gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Owing to its momentous pathogenic role, the diagnosis of H pylori infection remains a subject of interest. Helicobacter can be detected by invasive and non invasive methods. Aim: The purpose of this study was to evaluate the accuracy of stool antigen test as a non invasive method for the diagnosis of H pylori infection. Materials and Method: A prospective study was conducted in a tertiary medical college hospital. Patients presenting with dyspeptic symptoms were subjected to endoscopy and investigated for H pylori infection through rapid urease test, histopathology and culture. Stool samples were also collected from these patients and tested for H pylori infection by a rapid Hpylori Stool Antigen test. H pylori status was defined as positive when both rapid urease test (RUT) and histopathology were positive or culture alone was positive for biopsy based invasive methods. Similarly a positive rapid HpSA test also indicates H pylori infection. Results: Of the 100 patients tested, 63 were H pylori infected by the endoscopy based invasive methods, and 54 by the non-invasive rapid HpSA test. The sensitivity, specificity and accuracy of H pylori stool antigen test were 85.7%, 88% and 91% respectively. Conclusion: The rapid HpSA test could be used as a noninvasive diagnostictest for H pylori infection.

Diagnosis of active Helicobacter pylori infection in intellectually disabled (ID) children is problematic because they are unable to cooperate with performance of invasive tests. In this study, the non-invasive methods of measuring serum IgG antibody concentrations and performing stool antigen tests were used to screen for H. pylori infection in ID children. Eighty-seven children with intellectual disabilities were studied. The amount of serum IgG antibody against H. pylori was measured by the ELISA method. Stool samples were examined using an amplified IDEIA HpStAR kit. To assess categorical variables, X(2) , Fisher's exact and Kappa tests were used. The stool antigen tests showed that 93.1% of the children had H. pylori antigen and the serology test that 85.1% of children were positive for H. pylori IgG antibodies. Agreement between results of H. pylori stool antigen (HpSA) testing and IgG antibody serology was 82.8%; however, according to the kappa measure of agreement this agreement is not statistically significant (value, 0.128; P = 0.19). Discordant results were observed for 15 children (17.2%): 11 (12.6%) who were positive on HpSA test but negative by serology and 4 (4.6%) who were IgG seropositive but had negative HpSA tests. This study showed a notably higher rate of H. pylori infection in ID children than has been reported by others for non-ID children from the same geographical area. The HpSA test is a valid method for primary screening for H. pylori infection in ID children; it detects the specific antigens shed during active infections and has less cross-reactivity than serological tests that detect antibodies. HpSA is a sensitive non-invasive method for detecting infection in ID children and may serve as an accurate alternative to serology.

ObjectiveReliable non-invasive methods for detection of Helicobacter pylori (H. pylori) infection are required to investigate the incidence, transmission, and clearance of infection in childhood. Detecting bacterial antigens in stool offer an alternative noninvasive diagnostic test. However its accuracy in developing countries is not well established. The aim of this study was to evaluate the performance of stool antigen test for H pylori in Iranian children with recurrent abdominal pain necessitating endoscopy.MethodsOne hundred three children enrolled in this study. Endoscopy and biopsy was done on all patients providing a criterion standard for validation of the H. pylori stool antigen (HpSA) tests. The presence of H. pylori organisms in stool was determined by an enzyme-linked immunosorbent assay using a commercially available polyclonal antibody. HpSA sensitivity, specificity, and positive and negative likelihood ratios were determined with reference to the results of cultures of gastric biopsy.FindingsOf the 103 children tested 41 (39.8%) and 39 (37.8%) were positive for H. pylori according to the results of cultures of gastric biopsy and HpSA, respectively. The sensitivity, specificity, and positive and negative likelihood ratios of HpSA were found to be 85%, 93%, 89.7%, and 90%, respectively.ConclusionIn this pilot study, a low-cost and rapid diagnostic technique, stool antigen test proved to be highly sensitive and specific for detecting H pylori infection in children with recurrent abdominal pain. Our results are comparable to those reported elsewhere in children and demonstrate that the HpSA test can replace endoscopy and biopsy for detecting H. pylori infection.

Background: Helicobacter pylori is the most common chronic bacterial infection globally and is the underlying cause of many disorders, including dyspepsia. Also, the prevalence of gastric cancer in Zanjan city is high. Therefore, this study investigates the prevalence of H. pylori infection in patients with dyspepsia by the H. pylori stool antigen (HpSA) test. Materials and Methods: This cross-sectional study was performed on patients over 18 years of age who were referred to Shafieieh Special Clinic in Zanjan with dyspepsia during 2019-2020. First, the HpSA test was examined for H. pylori infection. Since the results of two separate tests are needed to prove that H. pylori infection is negative, the serological test was used in the patients with HpSA negative results. Results: Based on the demographic information of the present study, most patients (70.1%) were under 40 years old, and most (55.1%) were women. Smoking, alcohol, drug, and non-steroidal anti-inflammatory drugs (NSAIDs) use in patients were 16.5%, 6.3%, 7.9%, and 39.4%, respectively. The highest and lowest symptoms were abdominal pain (44.9%) and burp (22%), respectively. Except for the relationship between positive serological results and age (P˂0.001), no significant relationship was found between other variables (P≥0.05). Based on the HpSA test, H. pylori infection was seen in 56.7% of patients. By the serological test, another 29 patients had H. pylori infection. Therefore, the total number of patients was 101, and the overall prevalence of H. pylori increased to 79.5%. Conclusion: The results of the present study showed that the overall prevalence of H. pylori infection was high compared to previous studies. Also, above the age of 40 years, female gender in HpSA test and male gender in serology test, higher education level, and the presence of risk factors (smoking, alcohol, and NSAIDs) have a higher positive test for H. pylori.

Aims: Helicobacter pylori (H. pylori) is the primary causative agent of peptic ulcers in multiple developing countries, including Bangladesh. This study was designed to investigate the diagnostic value of a rapid immunochromatography-based H. pylori stool antigen (HpSAg) test to screen for H. pylori infection in a Bangladeshi population. Methodology and results: A total of 140 suspected peptic ulcer patients who underwent an upper gastrointestinal endoscopy at Chittagong Medical College and Hospital, Chattogram, Bangladesh were included in the study. A histopathology, rapid urease test (RUT), and microscopic examination of the stained smears were conducted to define the H. pylori-positive cases. Later, a stool antigen detection test was performed for the H. pylori-positive status group, the H. pylori-negative status group, the indeterminate status group, and the healthy controls. Out of the 140 suspected peptic ulcer patients, 75 (53.6%) patients were confirmed to have peptic ulcers or erosions. Although the proportion of antral erosion was 57.4% in patients who were under 40 years old, it decreased to 23.4% in patients over 40 years old. Patients over 40 years of age mostly suffered from pyloric erosion (42.9%). All peptic ulcer patients were also positive according to the histopathological analysis. However, microscopic grading of the curved bacilli and RUT were found among 93.3% (70/75) and 89.3% (67/75) patients who were positive, respectively. In our study, high sensitivity (95%), specificity (80%), and diagnostic accuracy (91%) scores for the HpSAg assay were obtained. Conclusions, significance, and impact of the studies: The HpSAg test, as a comparatively less sophisticated assay, can be efficient at detecting the presence of H. pylori pre- and post-therapy, and it provides more valid test results than other invasive test methods.

Helicobacter pylori is one of the most pathogenic organisms that cause gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma in humans. The main aim of this study was to determine the H. pylori infection among patients undergoing upper GI endoscopy and to compare the efficacy of the diagnostic method of H. pylori infection including invasive tests (biopsy-based tests like the rapid urease test (RUT), direct smear, and culture) and the noninvasive test (HpSA). A total of 100 stool samples and 200 gastric biopsy specimens were collected (2 samples from each patient) from June to November 2019. Stool samples were processed for the detection of an H. pylori stool antigen (HpSA) by a kit method. One biopsy specimen was processed for the RUT, and another was transported to the laboratory in an Eppendorf tube containing normal saline for preparation of the smear and culture. Out of 100 participants, 26% were found to be H. pylori positive by the RUT, 11% by the direct smear, 6% by the culture, and 17% by the stool antigen test. The prevalence of H. pylori infection was found to be 14%, considering at least two of the three biopsy-based tests that gave positive results. H. pylori infection was found to be higher in the age group of 46–55 years. The overall prevalence of H. pylori infection was higher in gastric ulcer cases, followed by erosive pangastritis and gastroduodenitis. Tea drinking habits and the frequency of meal consumption more than twice a day were found to be significantly associated with H. pylori infection (P < 0.05). Hence, the RUT was found to be more efficient than the direct smear and the culture method for finding H. pylori in the biopsy sample. However, none of these methods can be considered to be the gold standard alone. Thus, the RUT combined with other tests is preferable for the detection of H. pylori.

To evaluate the Helicobacter pylori stool antigen (HpSA) test in the assessment of H. pylori infection and the effect of omeprazole treatment on its accuracy. Study 1: 140 dyspeptic patients were enrolled in the study and defined as H. pylori positive if histology and rapid urease test, or culture alone were positive. HpSA was performed on all patients and 13C-urea breath test (UBT) on 87. Study 2: 75 patients testing positive using both UBT and HpSA, were given omeprazole 20 mg for 2 weeks (Group A) or omeprazole 40 mg for 2 weeks (Group B), or OAC for 1 week (group C). A Helicobacter pylori stool antigen test was performed on all patients on days 3, 5, 7 and 14 during treatment, and also on days 7 and 14 post-treatment in groups A and B. UBT was performed in groups A and B on days 7 and 14 during treatment, and days 7 and 14 post-treatment. 80/140 patients were H. pylori positive. The sensitivity and specificity of HpSA were 93.8 and 90%, similar to UBT (93.9 and 92.1%). Omeprazole significantly reduced both HpSA and UBT values, resulting in a decreased accuracy. Of 25 patients receiving 20 mg omeprazole, HpSA gave 5 and 6 false negatives after 7 and 14 days treatment respectively, while UBT gave 4 and 7 false negatives after 7 and 14 days treatment. Of 25 patients receiving 40 mg omeprazole, HpSA gave 7 and 9 false negatives after 7 and 14 days of treatment, while UBT gave 8 and 9 false negatives after 7 and 14 days of treatment. Two weeks after stopping omeprazole treatment, the HpSA and UBT were positive in all cases. The Helicobacter pylori stool antigen test is valuable in the assessment of H. pylori infection. Short-term omeprazole treatment decreases the accuracy of both HpSA and UBT in a similar manner.

Diagnosis of Helicobacter pylori infection by stool antigen test in southern Taiwan.

Background: Helicobacter pylori is the most common chronic bacterial infection globally and is the underlying cause of many disorders, including dyspepsia. Also, the prevalence of gastric cancer in Zanjan city is high. Therefore, this study investigates the prevalence of H. pylori infection in patients with dyspepsia by the H. pylori stool antigen (HpSA) test. Materials and Methods: This cross-sectional study was performed on patients over 18 years of age who were referred to Shafieieh Special Clinic in Zanjan with dyspepsia during 2019-2020. First, the HpSA test was examined for H. pylori infection. Since the results of two separate tests are needed to prove that H. pylori infection is negative, the serological test was used in the patients with HpSA negative results. Results: Based on the demographic information of the present study, most patients (70.1%) were under 40 years old, and most (55.1%) were women. Smoking, alcohol, drug, and non-steroidal anti-inflammatory drugs (NSAIDs) use in patients were 16.5%, 6.3%, 7.9%, and 39.4%, respectively. The highest and lowest symptoms were abdominal pain (44.9%) and burp (22%), respectively. Except for the relationship between positive serological results and age (P˂0.001), no significant relationship was found between other variables (P≥0.05). Based on the HpSA test, H. pylori infection was seen in 56.7% of patients. By the serological test, another 29 patients had H. pylori infection. Therefore, the total number of patients was 101, and the overall prevalence of H. pylori increased to 79.5%. Conclusion: The results of the present study showed that the overall prevalence of H. pylori infection was high compared to previous studies. Also, above the age of 40 years, female gender in HpSA test and male gender in serology test, higher education level, and the presence of risk factors (smoking, alcohol, and NSAIDs) have a higher positive test for H. pylori.

Various testing methods are successfully applied to the diagnosis of Helicobacter pylori infection, but noninvasive techniques are still needed for therapeutic monitoring, especially in children. In the search for new noninvasive techniques for the diagnosis of H. pylori infection, the authors evaluated an enzyme immunoassay for the detection of H. pylori antigen in stool (HpSA). The authors studied 62 H. pylori-positive children with chronic gastritis and 45 control subjects. H. pylori infection was diagnosed using cultures and histology of gastric biopsy specimens and a stool antigen test before treatment (clarithromycin, amoxicillin, omeprazole for 7 days) and 4 weeks to 6 weeks after treatment. Before therapy, antigen in stool was detected in 55 of 62 H. pylori-positive patients, which indicates that the sensitivity of the HpSA test was 88.7%. Of the 45 control subjects (with negative culture and histology results), 43 had negative results for H. pylori in the stool test (specificity, 95.5%). After completion of therapy, eradication was obtained (and confirmed by culture and histology) in 53 of the 62 H. pylori-positive children (85.5%). Four weeks to 6 weeks after eradication therapy, the sensitivity, specificity, positive predictive value, and negative predictive value of the stool antigen (HpSA) test were 88.9%, 96.2%, 80%, and 98%, respectively. The accuracy of the HpSA test for the detection of H. pylori in human stool 4 weeks to 6 weeks after treatment is comparable with the accuracy of the culture results. The stool antigen (HpSA) test was found to be a useful method for posttreatment eradication testing of infection in children.

The aim of the study was to compare 3 stool antigen tests for diagnosis of Helicobacter pylori infection in adult patients with dyspeptic complaints before eradication therapy. We compared 2 enzyme immunoassays (EIAs: Premier Platinum Helicobacter pylori Stool Antigen [HpSA] Plus and Helicobacter pylori Antigen [Hp Ag]) and one immunochromatographic assay (H. pylori fecal antigen test-lateral-flow chromatography) in detecting H. pylori. All the investigated stool antigen tests were made of monoclonal antibodies. We evaluated 168 adult patients with H. pylori infection by using 2 criterion standard methods (histological and rapid urease tests) together. The sensitivity and specificity were 90% and 91%, respectively, for the Premier Platinum HpSA Plus, 77% and 91%, respectively, for the Hp Ag, and 81% and 92%, respectively, for the H. pylori fecal antigen test, respectively. The best agreement between the criterion standard tests and the stool antigen tests used in the study was with the Premier Platinum HpSA Plus. Immunochromatographic assay-based stool antigen test (H. pylori fecal antigen test) was found to be more sensitive than the EIA-based test (Hp Ag). One of the 2 important conclusions obtained from the study was that the Premier Platinum HpSA Plus was found to be the most accurate test for the diagnosis of H. pylori infection in adult dyspeptic patients before eradication therapy, and the other was that monoclonal and high-quality, reliable immunochromatographic assay tests are a good option especially for small hospital laboratories that do not have appropriate equipment for performing the EIA and working on few samples.

: The prevalence of Helicobacter pylori infection among Aboriginal Australians children is unclear. The aims of the present study are to determine the prevalence of H. pylori infection among young Aboriginal children recovering from acute diarrheal disease in hospital and to evaluate the H. pylori stool antigen test as a noninvasive diagnostic test in this setting. : This was a prospective comparative study using the C-Urea Breath Test as reference standard. Fifty-two children between 4 months and 2 years of age were consecutively enrolled. These children comprised a representative sample of Australian Aboriginal children admitted to hospital with acute diarrheal disease from remote and rural communities across Northern Territory of Australia. : The overall prevalence of H. pylori was 44.2%. The stool antigen test had a sensitivity of 0.55 (95% confidence interval [CI]: 0.35-0.73) with a positive predictive value of 0.65 (95% CI: 0.42-0.82). The specificity was 0.68 (95% CI: 0.46-0.84) with a negative predictive value of 0.58 (95% CI: 0.39-0.75). Analysis of receiver operator characteristic curve yielded an overall accuracy of the stool antigen test of 61% (48%-75%). : The prevalence of H. pylori infection among very young Aboriginal children from remote and rural communities was high and consistent with early acquisition. The diagnostic accuracy of the stool antigen test to diagnose H. pylori in this setting was poor.