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 the effects of a proton pump inhibitor on Helicobacter pylori stool antigen testing.

BACKGROUND: Some patients find it difficult to discontinue proton pump inhibitors (PPIs). Unlike the 13 C-urea breath test (UBT), the stool antigen test (SAT), particularly when domestically produced kits are used, may be less likely to yield false-negative results. METHODS: This prospective study included a convenience series of 35 healthy Japanese subjects. Based on a statistical calculation, acceptable numbers of subjects were considered at least 21 and 11 with and without Helicobacter pylori (H. pylori) infection, respectively. The H. pylori infection was determined using the UBT or rapid urease test. SATs were performed with three novel domestically produced kits (the rapid immunochromatography tests Quick Navi™-H. pylori [Navi™] and Quick Chaser® H. pylori [Chaser®], and the bioluminescent enzyme immunoassay test BLEIA® 'EIKEN' H. pylori Antigen [BLEIA®]) before and after oral PPI administration (30 mg lansoprazole once daily for 14 days). For each kit, the sensitivities and specificities were calculated and compared before and after PPI administration. Furthermore, the cutoff index (COI) values of BLEIA® before and after PPI administration were compared in H. pylori-infected subjects. RESULTS: H. pylori infection was detected in 68.6% (24/35) of the included subjects. The sensitivities and specificities before versus after PPI administration were as follows: 79.2% (19/24) and 100.0% (11/11) versus 75.0% (18/24) and 100.0% (11/11) for Navi™, respectively (p = 1); 87.5% (21/24) and 100.0% (11/11) versus 75.0% (18/24) and 100.0% (11/11) for Chaser®, respectively (p = .371); 100.0% (24/24) and 100.0% (11/11) versus 95.8% (23/24) and 100.0% (11/11) for BLEIA®, respectively (p = 1). The median COI values of BLEIA® before and after PPI administration were 1389.0 and 3207.25, respectively (p = .0839). CONCLUSIONS: In stool specimens, H. pylori antigenicity is maintained even during PPI use. SAT using a bioluminescent enzyme immunoassay is particularly recommended because of its extremely high sensitivity.

Clinical performance of the H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ assays, novel stool antigen tests for diagnosis of Helicobacter pylori.

Infection with Helicobacter pylori is a global health issue, and rapid and accurate testing is a key to diagnosis. We aimed to assess the performance of two novel enzyme immunoassays (EIA), the H. PYLORI QUIK CHEK™ and the H. PYLORI CHEK™ assays, for the detection of H. pylori antigen in stool. Patients from five geographically diverse sites across the USA, Germany, and in Bangladesh were tested for infection with Helicobacter pylori with the two novel stool antigen tests and two commercially available stool antigen assays. All patients provided a stool sample and underwent esophagogastroduodenoscopy for biopsy. Results were compared to a clinical diagnosis using a composite reference method consisting of histological analysis and rapid urease testing of the biopsy. A total of 271 patients, 68.2% female and mean age of 46 years, were included. The overall prevalence of H. pylori infection was 24.1%. The sensitivity of the H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ was 92% and 91%, respectively. The specificity of H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ was 91% and 100%, respectively. No significant cross-reactivity against other gut pathogens was observed. The H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ assays demonstrate excellent clinical performance compared the composite reference method.

Stool Antigen Testing, a Reliable Noninvasive Method of Assessment of Helicobacter pylori Infection Among Patients with Gastro-duodenal Disorders in Cameroon.

BACKGROUND: Several techniques such as invasive and noninvasive are used for the diagnosis of H. pylori infection. AIM: The aim of this study was to compare the results of rapid urease test, stool antigen test and serology in diagnosing H. pylori infection in Cameroon. METHODS: Hundred patients (66 women and 34 men) were enrolled. Each patient gave a written consent. The study was approved by the local Ethical Committee of Medical Sciences and the institutional review board. From each patient, blood, stool and gastric biopsies samples were collected for H. pylori detection using three methods: stool antigen test, serology and rapid urease test (RUT), taken as gold standard. Statistical analysis was performed using Graph pad Prism 7. RESULTS: Helicobacter pylori infection was detected in 43%, 45% and 73% of patients based on the RUT, stool antigen test and serology, respectively. The difference was statistically significant between serology and RUT (P = 0.0026), but not between stool antigens test and RUT (P = 0.288). Taken RUT as gold standard, the sensitivity, specificity, positive and negative predictive values of stool antigens test and serology were 65.11, 70.17, 62.22 and 72.72%; 88.37, 40.35, 55.77 and 82.14%, respectively. The accuracy of stool antigen test and serology was 68 and 61%, respectively. CONCLUSIONS: Our finding showed that stool antigen test can be used as a noninvasive method of assessment of H. pylori infection in our setting. Serological test can be used in screening; however, further diagnostic tests need to be carried out to confirm seropositive cases.

Review: Helicobacter pylori infection in children.

Helicobacter pylori infection in children and adolescents differs in comparison to adults with respect to epidemiology, host responses, and disease manifestations. Furthermore, treatment options are limited in this population and antibiotic resistance rates continue to increase. Therefore, ongoing research is vital to understand disease pathogenesis and provide optimal management of children with infection. This review summarizes relevant publications from April 2019 to March 2020. Similar to adults, recent studies show a decreasing prevalence of infection in the pediatric population. Studies of pathogenesis investigated serum immune responses and the potential inverse association of infection and allergy. Several studies investigated the effect of H pylori and related inflammation on the gut microbiome. The recommendation of endoscopy-based testing to identify the cause of symptoms and not just H pylori, reserving noninvasive UBT or stool antigen tests for post-eradication follow-up, was supported by the current literature.

Review: Diagnosis of Helicobacter pylori infection.

New imaging techniques are still the topic of many evaluations for both the diagnosis of Helicobacter pylori gastritis and the detection of early gastric cancer. Concerning invasive tests, there were studies on the reuse of the rapid urease test material for other tests, and a novel fluorescent method to be used for histology but with limited sensitivity. Progress occurred essentially in the molecular methods area, especially next-generation sequencing which is applied to detect both H pylori and the mutations associated with antibiotic resistance. For non-invasive tests, a few studies have been published on the validity of breath collection bags, the shortening of the testing time, the performance of different analysers or the added value of citric acid in the protocol. The accuracy of serological immunochromatographic tests is also improving. Multiplex serology detecting antibodies to certain proteins allows confirmation of a current infection. Dried blood spots can be used to collect and store blood without a loss of accuracy. Finally, the serum antibody titer can be useful in predicting the risk of gastric cancer. Several stool antigen tests were evaluated with good results, and a novel test using immunomagnetic beads coated with monoclonal antibodies is potentially interesting. PCR detection in stools can also be effective but needs an efficient DNA extraction method. The use of easyMAG® (bioMérieux) combined with Amplidiag® H pylori + ClariR (Mobidiag) appears to be powerful.

Application of Helicobacter pylori stool antigen test to survey the updated prevalence of Helicobacter pylori infection in Taiwan.

BACKGROUND AND AIM: The reported prevalence of Helicobacter pylori infection in Taiwan was 54.4% in 1992. An updated prevalence of H. pylori infection in asymptomatic adults is lacking in Taiwan. We aimed to assess the updated age-standardized prevalence of H. pylori infection in asymptomatic subjects and in patients with dyspepsia and to assess the accuracy of H. pylori stool antigen (HpSA) test for screening of H. pylori in Chinese population. METHODS: Asymptomatic adult subjects (N = 189) were screened for H. pylori infection using HpSA, serology, and 13 C-urea breath test (13 C-UBT) in 2016-2017. Adult patients with dyspepsia (N = 145) were screened for H. pylori using 13 C-UBT, HpSA, serology, rapid urease test, and histology during 2016-2018. Two types of HpSA, including the Diagnostec HpSA ELISA Kit (HpSA ELISA) and Rapid Test Kit (HpSA Rapid), were used in this study. Sensitivity, specificity, and accuracy of the HpSA tests were calculated using the 13 C-UBT as golden standard test. RESULTS: The unadjusted prevalence of H. pylori was 21.2% in asymptomatic adults and 37.9% in patients with dyspepsia (P < 0.001). The age-standardized prevalence of H. pylori was 28.9% in asymptomatic adults in Taiwan. Of the 334 patients included for analysis, the area under the curve of HpSA ELISA test was 0.978, and the optimal cutoff value of optical density was 0.03. The sensitivity, specificity, and accuracy of the HpSA ELISA were 0.929, 0.983, and 0.967, respectively. The sensitivity, specificity, and accuracy of the HpSA Rapid were 0.929, 0.958, and 0.949, respectively. CONCLUSIONS: The prevalence of H. pylori infection has decreased in Taiwan. HpSA test is an accurate tool for screening of H. pylori in Chinese population.

Accuracy of rapid Helicobacter pylori antigen tests for the surveillance of the updated prevalence of H. pylori in Taiwan.

BACKGROUND: The updated prevalence of Helicobacter pylori (H. pylori) is lacking in Taiwan. We aimed to assess the accuracy of Vstrip® H. pylori Stool Antigen Rapid Test (Vstrip®HpSA) in the detection and surveillance of the updated prevalence of H. pylori in Taiwan. METHODS: A total of 347 adult subjects including 152 volunteers and 195 symptomatic patients were recruited. Stool samples were collected for detection of H. pylori using Vstrip® HpSA, ImmunoCard STAT!® HpSA and Premier Platinum HpSA® PLUS. All subjects who have completed the stool sample collections were included in the ITT analysis. The sensitivity, specificity, and accuracy of Vstrip® HpSA were calculated compared to gold standard test with 13C-Urea breath test. RESULTS: The un-adjusted prevalence of H. pylori infection was 22.5% (95% CI: 18.3-27%) in 2018. The age-standardized prevalence of H. pylori was 21.8% in asymptomatic adults in Taiwan. The sensitivity, specificity, and accuracy of the Vstrip® HpSA, and ImmunoCard STAT!® HpSA tests were 91% (95% CI: 82-96%) versus 76.9% (95% CI: 66-86%), 97% (95% CI: 94.1-98.6%) versus 97% (95% CI: 94.1-98.6%), and 95.7% (95% CI: 92-97%) versus 92.5% (95% CI: 89-95%), respectively. CONCLUSION: The age-standardized prevalence of H. pylori infection in Taiwan was 21.8% in asymptomatic adults in 2018. The Vstrip® HpSA had equivalent performance as the ImmunoCard STAT!® HpSA, and can be used in future mass screening of H. pylori infection for gastric cancer prevention.

Helicobacter Pylori Infection in Amniotic Fluid May Cause Hyperemesis Gravidarum.

Objectives: Limited data are available from recent trials involving pregnant women to guide Helicobacter pylori infection diagnosis. There are no data about the presence of H. pylori in the amniotic fluid as well. Furthermore, the relation between amniotic fluid H. pylori and hyperemesis gravidarum (HG) has not been characterized yet. Materials and Methods: This is a prospective study conducted after obtaining approval from the Ethics Committee. Pregnant women undergoing amniocentesis were enrolled in the study. The stool antigen test assessed the presence of H. pylori in amniotic fluid. A perinatologist independently performed an amniocentesis. The obtained amniotic liquid was sent to the laboratory to evaluate H. pylori infection by stool H. pylori antigen assay. We determined the rate of H. pylori in amniotic fluid and assessed relations between H. pylori infection and pregnancy outcome, including HG. Results: Between May and September 2017, we enrolled 48 pregnant women who underwent amniocentesis to detect possible fetal malformations. Patients were divided into two groups regarding the HG status. There were significant differences between the groups in terms of H. pylori infection presence. Among them, 28 (58.3%) were found to have a positive H. pylori test in their amniotic fluid. The rate of HG was significantly higher (71.4%) in patients who tested positive for H. pylori in amniocentesis than the H. pylori-negative group (20%), (p<0.001). Conclusions: The study's main new finding is that presence of H. pylori in the amniotic fluid is possible. Our data suggest that H. pylori-infected amniotic fluid is associated with the experience of past HG. The current study may have important implications for HG detection and help identify patients who would benefit from future preventive strategies.

Evaluation of a Novel Stool Antigen Rapid Test Kit for Detection of Helicobacter pylori Infection.

The Quick Chaser H. pylori (QCP), which is a novel antigen detection kit for Helicobacter pylori, was developed recently. The previous examination kits targeted the catalase of H. pylori; however, this new test kit, to the best of our knowledge, is the first kit to target the flagellar protein of H. pylori The present study aimed to evaluate the efficacy of QCP compared with that of the already commercially available rapid test kit Testmate Rapid Pylori Antigen (TRP). TRP and QCP were utilized in 71 participants. The positive and negative concordance ratios of QCP to TRP were 100% (57/57) and 92.9% (13/14), respectively. Sensitivity based on the rapid urease test and culture test was 92.3%. Results of the dilution sensitivity test showed that QCP was eight times more sensitive to an H. pylori standard strain and the clarithromycin (CAM)-resistant clinical isolate and four times more sensitive to a CAM-susceptible clinical isolate than TRP. For the cross-reactivity test, 27 strains that exist in human feces, such as the Helicobacter genus, Bifidobacterium genus, Lactobacillus genus, and other resident bacteria, were selected. The results obtained using QCP were all negative, and no cross-reaction was observed. In conclusion, compared with TRP, QCP can detect H. pylori using clinical specimens with high sensitivity, regardless of CAM susceptibility and tolerance. No cross-reactivity was observed with other intestinal bacteria in humans. The kit is considered extremely useful in clinical settings.

Review: Diagnosis of Helicobacter pylori infection.

Endoscopic imaging of the stomach is improving. In addition to narrow band imaging, other methods, for example, blue light imaging and linked color imaging, are now available and can be combined with artificial intelligence systems to obtain information on the gastric mucosa and detect early gastric cancer. Immunohistochemistry is only recommended as an ancillary stain in case of chronic active gastritis without Helicobacter pylori detection by standard staining, and recommendations to exclude false negative H. pylori results have been made. Molecular methods using real-time PCR, droplet digital PCR, or amplification refractory mutation system PCR have shown a high accuracy, both for detecting H. pylori and for clarithromycin susceptibility testing, and can now be used in clinical practice for targeted therapy. The most reliable non-invasive test remains the 13 C-urea breath test. Large data sets show that DOB values are higher in women and that the cut-off for positivity could be decreased to 2.74 DOB. Stool antigen tests using monoclonal antibodies are widely used and may be a good alternative to UBT, particularly in countries with a high prevalence of H. pylori infection. Attempts to improve serology by looking at specific immunodominant antigens to distinguish current and past infection have been made. The interest of Gastropanel® which also tests pepsinogen levels was confirmed.

Magnitude of Helicobacter pylori and associated risk factors among symptomatic patients attending at Jasmin internal medicine and pediatrics specialized private clinic in Addis Ababa city, Ethiopia.

BACKGROUND: More than 50% of the people are infected worldwide with H. pylori which causes significant public health morbidity and mortality. The distribution is quite different from country to country. Hence, early information is very important to prevent upper gastrointestinal complications. The current study aimed to assess the magnitude of H. pylori and associated risk factors among symptomatic patients attending at Jasmin internal medicine and pediatrics specialized private clinic from August 2017 until May 2018 in Addis Ababa city, Ethiopia. METHODS: A cross-sectional study was conducted among 487 patients with upper gastrointestinal tract complaints attending at Jasmin internal medicine and pediatrics specialized private clinic from August 2017 until May 2018. Convenient sampling technique was used to enroll participants. Information regarding to risk factors was assessed using structured questionnaire. Stool samples were collected for H. pylori antigen test. Data was entered and analyzed using SPSS version20 statistical software and a p-value less than 0.05 was considered as statistically significant. RESULTS: The overall prevalence of H. pylori among participants using stool antigen was 36.8% (n = 179/487). Regarding to family income status, those who have low monthly income were more likely to be infected with H. pylori infection (AOR = 6.056, CI 95% = 1.603-22.881, P = 0.037). In addition, families with low educational level were more likely to be infected with H. pylori infection than higher level education (AOR = 4.150, CI95% = 1.059-16.270, P = 0.041). Number of family members in the house-hold, type of toilet they used and source of drinking water were not significantly associated with H. pylori infection. CONCLUSIONS: The prevalence of H. pylori infection was 36.8% and it was related to low income and low education levels. This finding calls for improving the socioeconomic status of the community. Moreover, further studies are needed to investigate potential risk factors for H. pylori infection.

Predictors of triple therapy treatment failure among H. pylori infected patients attending at a tertiary hospital in Northwest Tanzania: a prospective study.

BACKGROUND: Helicobacter pylori (H.pylori) infection is a common medical problem in resource limited areas. The treatment outcome after triple therapy has not been well studied in developing countries and preliminary data suggests a high rate of treatment failure. This study investigated the triple therapy treatment failure rate and associated factors among dyspeptic patients receiving H. pylori first line therapy at a tertiary hospital, Tanzania. METHODS: A prospective study in the Gastroenterology unit of the Bugando Medical Centre (BMC) was conducted between October 2015 and May 2017. All dyspeptic patients with stool antigen tests positive for H.pylori were given first line therapy, and stool antigen testing was repeated within 7 days and 5 weeks after completion of the treatment. Biopsies were taken before initiation of therapy and analysed for clarithromycin and quinolone resistance mutations using polymerise chain reaction (PCR) and sequencing. Adherence and other social-demographic characteristics were documented. RESULTS: A total of 210 patients were enrolled; the median age was 35 years (interquartile range, 27-48). First line treatment failure as defined by positive stool antigen 5 weeks post treatment was observed in 65/210 (31%) of patients. Independent predictors of first line treatment failure were presence of clarithromycin resistance mutations (OR: 23.12, 95% CI (9.38-56.98), P < 0.001) and poor adherence (OR: 7.39, 95% CI (3.25-16.77), P < 0.001). The sensitivity and specificity of stool antigen testing within 7 days after completion therapy in detecting treatment failure was 100 and 93.2%, respectively. CONCLUSION: Nearly one-third of patients with clarithromycin resistance mutations and poor adherence develop first line treatment failure. Routine stool antigen testing within seven days after completion of therapy can be considered in order to initiate second line treatment early to prevent associated morbidities.

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.

Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States.

Despite guidelines for detection and treatment of Helicobacter pylori infection, recommendations to test patients before and after therapy are commonly not followed in the United States. At the Houston Consensus Conference, 11 experts on management of adult and pediatric patients with H pylori, from different geographic regions of the United States, met to discuss key factors in diagnosis of H pylori infection, including identification of appropriate patients for testing, effects of antibiotic susceptibility on testing and treatment, appropriate methods for confirmation of infection and eradication, and relevant health system considerations. The experts divided into groups that used a modified Delphi panel approach to assess appropriate patients for testing, testing for antibiotic susceptibility and treatment, and test methods and confirmation of eradication. The quality of evidence and strength of recommendations were evaluated using the GRADE system. The results of the individual workshops were presented for a final consensus vote by all panel members. After the Expert Consensus Development meeting, the conclusions were validated by a separate panel of gastroenterologists, who assessed their level of agreement with each of the 29 statements developed at the Expert Consensus Development. The final recommendations are provided, on the basis of the best available evidence, and provide consensus statements with supporting literature to implement testing for H pylori infection at health care systems across the United States.

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.

Accuracy of two plasma antibody tests and faecal antigen test for non-invasive detection of H. pylori in middle-aged Caucasian general population sample.

OBJECTIVE: The aim of the study was to assess the accuracy of two plasma Helicobacter pylori (H. pylori) antibody test-systems and a stool antigen test (SAT) system in a general population sample in Latvia. MATERIALS AND METHODS: Blood and faecal samples were analysed in healthy individuals (40-64 years), referred for upper gastrointestinal endoscopy according to pilot study protocol within a population-based study investigating gastric cancer prevention strategies (GISTAR pilot study). Antibodies to H. pylori were assessed in plasma by latex-agglutination test and enzyme-linked immunosorbent assay (ELISA). H. pylori antigen in faecal samples was detected by a monoclonal enzyme immunoassay-based SAT. Histological assessment of H. pylori based on a modified Giemsa staining method was used as the gold standard. Individuals having received H. pylori eradication within one year prior to enrolment were excluded. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy were calculated. Receiver-operating characteristic curves were designed to estimate the optimal diagnostic cut-off value of tests. RESULTS: The analysis included 779 participants for latex-agglutination test, 1002 for ELISA and 672 individual samples for SAT. The sensitivity, specificity, PPV, NPV and overall accuracy were as follows: latex-agglutination test (86;81;87;80;84%), ELISA (97;72;83;94;86%) and SAT (87;81;87;81;85%), respectively. The optimal diagnostic cut-off value for ELISA test was ≥50.26 g/L. CONCLUSIONS: Although the performance of the three tests was comparable to each other, the three test systems showed suboptimal accuracy, with important implications for public health programs based on 'test-and-treat' strategy.

Feco-prevalence and risk factors of Helicobacter pylori infection among symptomatic patients at Dessie Referral Hospital, Ethiopia.

BACKGROUND: Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection in the world. It can result in various upper gastroduodenal diseases. The prevalence varies among countries, population groups within the same country and testing methods. The aim of the study was to determine feco-prevalence and risk factors of H.pylori infection among symptomatic patients in Amhara region, Northeast Ethiopia. METHODS: A cross sectional study was conducted in a total of 342 new consecutive outpatients with upper abdominal complaints at Dessie Referral Hospital from May to July, 2016. A structured questionnaire was used to collect the socio-demographic, lifestyle and environmental data. Stool samples were used to detect H. pylori specific antigen. Blood samples were assessed for anti-H. pylori IgG and ABO blood types. SPSS version 20.0 statistical software package was used for data analysis. Chi-square test and logistic regression were used in the analysis and P-value ≤0.05 was considered as statistically significant. RESULTS: H. pylori stool antigen and serum anti-H.pylori IgG detection rate was 30.4 and 60.5% respectively with kappa measure of agreement of 0.271. Antigen detection was significantly associated with family size (> 3) [AOR = 1.83, 95% CI: 1.10-3.05, p = 0.02], more persons (> 3) sharing the same bed room in the household [AOR = 2.91, 95% CI: 1.39-6.11, p = 0.005], alcohol consumption (> once a week) [AOR = 2.70, 95% CI: 1.49-4.89, p = 0.001] and individuals' blood type: group O [AOR = 8.93, 95%CI: 1.79-44.48, p = 0.008] and group A [AOR = 5.53, 95%CI: 1.08-28.36, p = 0.040]. Gender, age, marital status, occupation, educational level, residence, smoking as well as coffee, tea, fruits and vegetables consumption were not statistically associated with H. pylori antigen detection (p > 0.05). CONCLUSION: The overall H. pylori stool antigen and anti-H. pylori IgG detection rate was 30.4 and 60.5%, respectively. The test agreement was not strongly convincing and needs further evaluation. Alcohol consumption, overcrowding and ABO blood group were significantly associated with H. pylori antigen detection.

Evaluation of SD BIOLINE H. pylori Ag rapid test against double ELISA with SD H. pylori Ag ELISA and EZ-STEP H. pylori Ag ELISA tests.

BACKGROUND: Helicobacter pylori antibody titters fall very slowly even after successful treatment. Therefore, tests detecting H. pylori antibody lack specificity and sensitivity. On the other hand, H. pylori stool antigen tests are reported as an alternative assay because of their reliability and simplicity. However, the comparative performance of H. pylori stool antigen tests for detecting the presence of the bacterium in clinical specimens in the study area is not assessed. Therefore, in this study we evaluated the performance of SD BIOLINE H. pylori Ag rapid test with reference to the commercially available EZ- STEP ELISA and SD BIOLINE H. pylori Ag ELISA tests. METHODS: Stool samples were collected to analyse the diagnostic performance of SD BIOLINE H. pylori Ag rapid test kit using SD H. pylori Ag ELISA kit and EZ- STEP ELISA tests as a gold standard. Serum samples were also collected from each patient to test for the presence of H. pylori antibodies using dBest H. pylori Test Disk. Sensitivity, specificity, predictive values and kappa value are assessed. P values < 0.05 were taken statistically significant. RESULTS: Stool and serum samples were collected from 201 dyspeptic patients and analysed. The sensitivity, specificity, positive and negative predictive values of the SD BIOLINE H. pylori Ag rapid test were: 95.6% (95% CI, 88.8-98.8), 92.5% (95%CI, 89-94.1%), 86.7% (95% CI, 80.5-89.6), and 97.6% (95% CI, 993.9-99.3) respectively. CONCLUSION: The performance of SD BIOLINE H. pylori Ag rapid test was better than the currently available antibody test in study area. Therefore, the SD BIOLINE Ag rapid stool test could replace and be used to diagnose active H. pylori infection before the commencement of therapy among dyspeptic patients.

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.