Variation in the 13C-urea breath test value by nationality in Helicobacter pylori-infected children

Correlation between Quantitative 13C-Urea Breath Test and Helicobacter pylori Treatment Success in a Population-Based Cohort

Background

There are continual efforts to identify factors which influence the success of first-line therapy for Helicobacter pylori (H. pylori) infection. The ¹³C-urea breath test result (C13-UBT) utilizes H. pylori urease activity and is a highly accurate diagnostic assay. We aimed to determine whether the magnitude of C13-UBT result is related to treatment success.

Methods

Adult patients who underwent a first-time ¹³C-urea breath test between January 2010 and January 2016 were included. In order to isolate a naïve test-and-treat population who were unlikely to have undergone an initial endoscopy-based H. pylori test, we excluded patients > 45 years and those with a previous C13-UBT. Data were extracted from the Clalit Health Services laboratory database.

Results

A total of 94,590 subjects (36.1% male, age 28.5 ± 6.0 years) who underwent a first-time C13-UBT during the study period were included. C13-UBT was positive in 48,509 (51.3%) subjects. A confirmatory posttreatment C13-UBT was performed in 18,375 (37.8%), and eradication was successful in 12,018 (65.4%). The mean C13-UBT recording was 20.6 ± 16.2 DOB in subjects with successful eradication and 19.5 ± 13.1 DOB in subjects with treatment failure (OR, 1.01; 95% CI 1.00-1.01, p < 0.01). Among patients in the upper quintile of C13-UBT measurement, eradication was achieved in 67.6%, compared to 62.6% in the lower quintile (OR, 1.22; 95% CI 1.11-1.35, p < 0.01). Subjects in the top 1 percentile (C13-UBT ≥ 70 DOB) achieved eradication in 75.0%, compared to 65.3% among subjects with C13-UBT < 70 DOB (OR, 1.59; 95% CI 1.05-2.41, p < 0.01).

Conclusions

The superiority in H. pylori eradication observed in subjects with a higher C13-UBT DOB is small but significant. Further studies should examine the physiological and microbiological basis for this finding.

Optimization of 13 C-urea breath test threshold levels for the detection of Helicobacter pylori infection in a national referral laboratory

BACKGROUND

Threshold values for ¹³ C-urea breath test (13C-UBT) positivity may be affected by various sociodemographic, host, bacterial, and laboratory factors. Manufacturer recommended cutoffs for 13C-UBT assays may not be applicable in all settings. Optimizing 13C-UBT cutoffs may have profound public health ramifications. We aimed to determine the optimal threshold for 13C-UBT positivity in our population.

METHODS

Consecutive test samples collected at our central laboratory from patients undergoing a first-time 13C-UBT between 1 January 2010 and 31 December 2015 were included. The difference between values at 30 minutes and at baseline (T30-T0) was expressed as delta over baseline (DOB). Cluster analysis was performed on the 13C-UBT test results to determine the optimal cutoff point with minimal interclass variance.

RESULTS

Two lakhs thirty four thousand eight hundred thirty one patients (87 291 (37.2%) male, age 39.9 ± 19.9) underwent a first-time 13C-UBT, including 124 701 (53.1%) negative and 110 130 (46.9%) positive tests, using the manufacturer-recommended cutoff of 3.5 DOB. Cluster analysis determined an optimized cutoff of 2.74 DOB, representing an additional 2180 (0.93%) positive subjects who had been previously categorized as negative according to the manufacturer-specified cutoff of 3.5 DOB. Mean positive and negative DOB values were 19.54 ± 14.95 and 0.66 ± 0.51, respectively. The cutoffs for male and female subjects were 2.23 and 3.05 DOB, respectively. Threshold values for <45-year-olds, 45-60-year-olds and >60-year-olds were 2.67, 2.55, and 2.93 DOB, respectively. Of the 2180 (0.93%) patients with DOB 2.73-3.49, 289 (13.3%) performed a subsequent 13C-UBT and 140 (48.4%) remained positive when tested at 20.3 ± 14.4 months.

CONCLUSIONS

Major referral laboratories should optimize threshold values for 13C-UBT positivity for their geographical location. Different cutoff values should be applied for male and female subjects.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

DIAGNOSTIC ACCURACY OF UREA BREATH TEST FOR HELICOBACTER PYLORI INFECTION IN CHILDREN WITH DYSPEPSIA IN COMPARISON TO HISTOPATHOLOGY

ABSTRACT Background - Helicobacter pylori infection is the gram negative bacillus with the close association with chronic antral gastritis. Objective - In this study, we evaluate the accuracy of urea breath test (UBT) with carbon isotope 13 in comparison with histopathology of gastric antrum for detection of H. pylori infection in children with dyspepsia. Methods - This cross-sectional study was performed at specialized laboratory of Shiraz Gastroenterohepatology Research Center and Nemazee Hospital, Iran, during a 12-months period. This study investigated the sensitivity, specificity, and positive and negative predictive values of UBT in comparison with biopsy-based tests. We included a consecutive selection of 60 children who fulfilled Rome III criteria for dyspepsia. All children were referred for performing UBT with carbon isotope 13 (C13) as well as endoscopy. Biopsies were taken from antrum of stomach and duodenum. The pathologic diagnosis was considered as the standard test. Results - The mean age of the participants was 10.1±2.6 (range 7-17 years). From our total 60 patients, 28 (46.7%) had positive UBT results and 32 (53.3%) had negative UBT results. Pathologic report of 16 (57.1%) out of 28 patients who had positive UBT were positive for H. pylori and 12 (42.9%) ones were negative. Sensitivity and specificity of C13-UBT for detection of H. pylori infection were 76.2% and 69.2% respectively. Conclusion - Sensitivity and specificity of C13-UBT for detection of H. pylori infection were 76.2% and 69.2% respectively. Another multicenter study from our country is recommended.

Sequential therapy compared with standard triple therapy for Helicobacter pylori eradication in children: a double-blind, randomized, controlled trial

OBJECTIVE

To determine the effectiveness of sequential therapy compared with standard triple therapy for Helicobacter pylori eradication in children.

STUDY DESIGN

In 107 children with H pylori infection confirmed with 2 of 3 tests ((13)C-urea breath test, histopathology, rapid urease test), we conducted a double-blind, randomized, controlled trial comparing a sequential treatment (amoxicillin and omeprazole for 5 days followed by clarithromycin, tinidazole, and omeprazole for 5 days) to a 7-day standard triple eradication regimen (amoxicillin and clarithromycin plus omeprazole) followed by placebo for 3 days.

RESULTS

In the experimental group (n=52) compared with the control group (n=51), there was a significant difference in the H pylori eradication rate at 6 to 8 weeks after the completion of treatment (primary outcome), as confirmed with negative results on (13)C-urea breath test (45/52 or 86.5% versus 35/51 or 68.6%; relative risk, 1.26; 95% CI, 1.02-1.60). Groups did not differ in any of the secondary outcomes (ie, adverse effects, the need for discontinuation of the H pylori therapy, compliance with therapy).

CONCLUSIONS

In children with H pylori infection, sequential eradication therapy compared with standard triple therapy resulted in a higher eradication rate, although the difference was of borderline statistical significance.

Randomized, double-blind, placebo-controlled trial: effect of lactobacillus GG supplementation on Helicobacter pylori eradication rates and side effects during treatment in children

OBJECTIVE

To determine the effectiveness of Lactobacillus GG (LGG) in children with Helicobacter pylori infection undergoing eradication therapy.

MATERIALS AND METHODS

We conducted a double-blind, placebo-controlled, randomized trial comparing a 7-day, triple eradication regimen consisting of 2 antibiotics (amoxicillin tablets, 25 mg/kg twice per day, and clarithromycin tablets, 10 mg/kg twice per day) plus a proton pump inhibitor (omeprazole capsules, 0.5 mg/kg twice per day) supplemented with LGG (109 colony-forming units) or placebo in 83 children with H pylori infection confirmed by 2 of 3 tests (13C-urea breath test, histopathology, rapid urease test). The primary outcome measure was the H pylori eradication rate. The secondary outcome measure was the proportion of patients who experienced therapy-related adverse effects during anti-H pylori treatment.

RESULTS

The groups did not differ with respect to H pylori eradication rates. Of the 34 children in the LGG group, 23 (69%) experienced eradication, compared with 22 of 32 children (68%) in the placebo group (RR 0.98, 95% CI 0.7-1.4). The groups did not differ with respect to adverse effects.

CONCLUSIONS

In children with H pylori infection, supplementation of standard triple therapy with LGG did not significantly alter the eradication rate or side effects.

Low prevalence of Helicobacter pylori infection in Canadian children: a cross-sectional analysis

BACKGROUND

The incidence and prevalence rates of childhood Helicobacter pylori infection vary greatly by nation, with infection rates of 8.9% to 72.8% reported in developed and developing countries, respectively. To date, few studies have assessed the prevalence of H pylori in Canadian children, with studies limited to Aboriginal communities and single tertiary care centres from Ontario and Quebec.

OBJECTIVES

To determine the prevalence of H pylori in consecutive children referred to three Canadian tertiary care academic centres for upper gastrointestinal (GI) endoscopy due to upper GI symptoms, and to determine the sensitivity and specificity of the carbon-13-labelled urea breath test, the rapid urease test and the H pylori stool monoclonal antigen test.

RESULTS

Two hundred four patients were recruited. The prevalence of H pylori was 7.1%. Of the H pylori-positive patients, 41.7% were male, with a mean age of 10.3 years. Ethnic minorities accounted for 42% of the H pylori-positive patients. Consistent with previous observations, the sensitivity and specificity of the carbon-13-labelled urea breath test were 1.0 and 0.98, respectively. The sensitivity and specificity of the rapid urease test were 1.0 and 0.99, respectively. Stool samples were collected from 34 patients from one centre, with a sensitivity and specificity of 1.0 and 0.68, respectively. No defining symptoms of H pylori infection were evident and no peptic ulcer disease was demonstrated.

CONCLUSION

H pylori infection rates in Canadian children with upper GI symptoms are low, and are lower than those reported for other developed countries. Further studies are required in Canada to determine the prevalence in the general population and specifically in the populations at risk.

Helicobacter pylori, anemia, and iron deficiency: relationships explored among Alaska native children

BACKGROUND

Attempts to understand determinants of anemia and iron deficiency have led researchers to examine the role of Helicobacter pylori infection. The current study assessed determinants of anemia and iron deficiency, including H. pylori, in Alaska Native children.

METHODS

In 1999, a population-based survey was conducted among 86 children (67% response rate), mean age of 43.7 months (standard deviation = 16.8 months). Samples of breath, stool, and venous blood were obtained from children for measures of anemia, iron deficiency, H. pylori, fecal blood loss, and current inflammation. Standardized interviews with parents provided information on demographics, illness, and intake of dietary iron, iron-absorption inhibitors, and enhancers.

RESULTS

Of the 86 children studied, 17.4% were anemic and 38.6% were iron deficient. Forty-one percent of the cohort had H. pylori-specific IgG antibodies, 86% tested positive by the urea breath test (UBT), and 80% tested positive by the stool antigen test. Presence of H. pylori antibodies emerged as a significant risk factor for anemia and iron deficiency in adjusted analyses controlling for demographic factors, current inflammation, and antibiotic use. In contrast, children with positive UBT or stool antigen results were significantly less likely to have anemia or iron deficiency than those with negative results.

CONCLUSIONS

Results from different measures of H. pylori may reflect different stages of infection. Relationships between H. pylori and anemia/iron deficiency may depend on the phase of infection measured, with serologic tests reflecting established H. pylori infection associated with anemia/iron deficiency, and UBT and stool antigen results reflecting an earlier stage of infection.

13C urea breath test for (Helicobacter pylori): determination of the optimal cut-off point in a Canadian community population

AIM

To determine the test characteristics and the optimal cut-off point for the (13)C urea breath test ((13)C UBT) in a Canadian community laboratory setting.

METHODS

Of 2232 patients (mean age +/- SD: 51+/-21 years, 56% female) who completed a (13)C UBT, 1209 were tested to evaluate the primary diagnosis of (Helicobacter pylori) infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the (13)C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the (13)C UBT against histology and microbiology using the calculated cut-off point.

RESULTS

The calculated cut-off points were 3.09 delta/1000 for the whole study population (n=2232), 3.09 delta/1000 for the diagnosis group (n=1209) and 2.88 delta/1000 for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 delta/1000, the risk of false-positive and false-negative results was lower than 2.3%. The (13)C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active (H pylori) infection.

CONCLUSIONS

The (13)C UBT is an accurate, noninvasive test for the diagnosis of (H pylori) infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cut-off point of 3.0 delta/1000 for the (13)C UBT when used in a large Canadian community population according to a standard protocol.

Neue Epidemiologie der akuten gastrointestinalen Blutung

Due to progress in general medicine and especially in gastroenterology, the incidence of acute gastrointestinal hemorrhage could be expected to have decreased during the last 25 years. However, published epidemiological data cannot, in general, fulfill this hope. The interpretation of potential trends is, however, often limited by low study quality. For example, questionable bleeding sources such as erosions in the upper gastrointestinal tract or colon diverticula are often rather uncritically named the definitive causes of bleeding. However, there is clear evidence of changes in grouping of patients. After the almost complete disappearance of Helicobacter pylori in younger indigenous populations of most industrialized countries, it is mostly elderly comorbid people with additional risk factors (NSAID use, low-dose aspirin, anticoagulation) who are affected. Not unexpectedly, this group has generally experienced no change in incidence and in fact shows a deterioration of prognosis in case of acute bleeding.

Evidence of mother-child transmission of Helicobacter pylori infection

BACKGROUND

Low socioeconomical status is a major risk factor for natural acquisition of Helicobacter pylori (H. pylori) infection in developing countries. Its transmission route is unknown but studies suggest person-to-person transmission.

AIM

To evaluate seropositivity of anti-H. pylori antibodies in family members of infected symptomatic index patients as compared to family members of symptomatic uninfected index patients.

PATIENTS AND METHODS

One hundred and twelve family members of 38 patients who underwent endoscopy to exclude peptic disease were studied. Patients were deemed H. pylori infected or not infected when rapid urease test and histology were both positive or both negative. The family members underwent ELISA serology using the Cobas Core II Kit (Roche) and were classified into three groups: I - 29 family members of 10 H. pylori (+) duodenal ulcer index patients; II - 57 family members of 17 H. pylori (+) index patients without duodenal ulcer; III - 26 family members of 11 H. pylori (-) index patients.

RESULTS

Seropositivity of group I and II (infected patients) was higher than the control group, 83% vs 38%, specially in mothers, 81% vs 18%, and in siblings 76% vs 20%. Differences between fathers' seropositivity was not statistically significant in the three groups: 100% vs 86% vs 70%. Seropositivity of all family members (mother, father and siblings) between infected group (I vs II) was similar.

CONCLUSION

Prevalence of H. pylori infection was higher in family members of infected patients, but was similar among family members of infected patients with and without duodenal ulcer. H. pylori infection is more frequent in mothers and siblings of infected index children. A common source of infection cannot be excluded, but facts suggest that person-to-person transmission occurs, specially from mother to child.

Review article: 13C-urea breath test in the diagnosis of Helicobacter pylori infection -- a critical review

The urea breath test is a non-invasive, simple and safe test which provides excellent accuracy both for the initial diagnosis of Helicobacter pylori infection and for the confirmation of its eradication after treatment. Some studies have found no differences between urea breath test performed under non-fasting conditions. The simplicity, good tolerance and economy of the citric acid test meal probably make its systematic use advisable. The urea breath test protocol may be performed with relatively low doses (<100 mg) of urea: 75 mg or even 50 mg seem to be sufficient. With the most widely used protocol (with citric acid and 75 mg of urea), excellent accuracy is obtained when breath samples are collected as early as 10-15 min after urea ingestion. A unique and generally proposed cut-off level is not possible because it has to be adapted to different factors, such as the test meal, the dose and type of urea, or the pre-/post-treatment setting. Fortunately, because positive and negative urea breath test results tend to cluster outside of the range between 2 and 5 per thousand, a change in cut-off value within this range would be expected to have little effect on clinical accuracy of the test.

Prevalence of Helicobacter pylori infection in Warao lineage communities of Delta Amacuro State, Venezuela

The purpose of this study was the evaluation of Helicobacter pylori infections in children and adults from two indigenous communities of Delta Amacuro State, Venezuela, that differ in hygienic conditions of the housing. The evaluation was performed in 98 children (mean age 7 +/- 3.37 years) and their mothers (33.96 +/- 13.77 years) from two communities of Warao lineage. Anti-H. pylori serum IgG and secretory anti-H. pylori IgA antibodies were determined, as well as total secretory IgA and H. pylori antigens in feces. Serological prevalence of H. pylori infection was 38% in children and 84% their in mothers. Children from the community that had the most deficient sanitary and hygienic conditions had significantly lower titers of specific IgG antibodies and total secretory IgA (P<0.0001) and a high percentage of them had H. pylori antigens in their feces (P<0.0001). The levels of specific IgA were similar in both groups. The results indicate that in these populations there is a high prevalence of H. pylori infection and that poor hygienic conditions can increase the risk of infection and damage to the gastrointestinal tract.

Evaluation of [13C]urea breath test and Helicobacter pylori stool antigen test for diagnosis of H. pylori infection in children from a developing country

The [(13)C]urea breath test ((13)C-UBT) and Helicobacter pylori stool antigen test (HpSA) for the diagnosis of H. pylori infection in children were validated. The sensitivity, specificity, and positive and negative predictive values were 93.8, 99.1, 97.8, and 98.0%, respectively, for the (13)C-UBT and 96.9, 100, 100, and 98.0%, respectively, for HpSA. Both tests are appropriate for diagnosing H. pylori infection in children.

The incidence of Helicobacter pylori infection is not increased among obese young individuals in Greece

GOALS

To identify possible risk factors affecting the acquisition of Helicobacter pylori (Hp) infection and to investigate whether the incidence of infection is higher among obese and overweight verus normal-weight young adults in Greece.

STUDY

Serum was obtained from 224 young male Navy recruits (mean age, 22.84 years) during their induction into the Hellenic Navy. An enzyme-linked immunosorbent assay to detect Hp-specific IgG serum antibodies, as well as gastroscopy with biopsy, were used to identify the infected individuals. A structured questionnaire was filled out for each subject regarding environmental conditions, socioeconomic conditions, dietary habits, and data related to their personal and family health history.

RESULTS

H. pylori positivity rate was 27.23%. Univariate analysis recognized that the number of siblings in the same bedroom was significantly higher among Hp-positive than Hp-negative individuals. Logistic regression analysis showed that sharing the same bedroom with more than one sibling during childhood and consumption of fast food are independent predictors of Hp acquisition. The presence of obesity (body mass index > or =25 kg/m2) remained unrelated to the Hp status of the individuals.

CONCLUSIONS

These data suggest that the risk of Hp infection does not increase in overweight young persons. Sharing the same bedroom with more than one sibling during childhood is an important determinant in acquiring Hp infection. Increased fast food consumption could be an important source of the infection outside of the home.

Diagnosis of Helicobacter pylori infection in children: comparison of a salivary immunoglobulin G antibody test with the [(13)C]urea breath test

The prevalence of Helicobacter pylori infection in a population-based sample of 477 children (mean age plus minus standard deviation, 5.8 plus minus 0.5 years) determined by the [(13)C]urea breath test ([(13)C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [(13)C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively.

Detection of Helicobacter pylori organisms by Hp-fast in children

Hp-fast is a new rapid urease test (RUT) that has not been evaluated in children. The aim of the study was to prospectively compare the Hp-fast test to the CLOtest in children. Children with gastrointestinal symptoms who undergo diagnostic upper endoscopy were prospectively enrolled to the study. Antral gastric biopsies were evaluated for histology and for CLO-test and Hp-fast. Results were then compared to histology. Of the 94 children who participated, gastritis was found in 38 (40%), of whom 16 (42%) had associated H. pylori organisms. In two children, H. pylori organisms were identified without gastritis. The concordance between both RUT tests was 98%. A significant correlation was found between RUT results and histological factors or serology. The accuracy rate of both RUT increased significantly when different gold standards were utilized to detect Hp infection in children. The best correlation was found when histology and serology were considered as the gold standard for the diagnosis of H. pylori infection in children (sensitivity: 100% compared to 43-80% with other standards, respectively). In conclusion, the Hp-fast test result is comparable to CLOtest, but neither alone is sufficient to establish the diagnosis of Hp infection in children.