Role of 13C-urea breath test in experimental model of Helicobacter pylori infection in mice

Background: Animal models have been widely used to study Helicobacter pylori infection. Evaluation of H. pylori infection status following experimental inoculation of mice usually requires euthanasia. The ¹³C‐urea breath test (¹³C‐UBT) is both sensitive and specific for detection of H. pylori in humans. Thus, it would be very useful to have such a test with the same accuracy for the follow‐up of this infection in animal models of gastric infection. Accordingly, the purpose of this study was to develop and evaluate a ¹³C‐UBT method for following the course of H. pylori infection in a mouse model. Material and Methods: A total of 50 female C57BL/6 mice were gavaged three times with either 10⁸ colony‐forming units of H. pylori (n = 29) or saline solution only (n = 21). After 2 months of infection, mice were fasted for 14 hours and ¹³C‐UBT was performed using 300 μg of ¹³C‐urea. The mice were killed, and the stomach was removed and processed for immunohistochemistry and PCR. Results: The optimal time for breath sample collection in mice was found to be 15 minutes. The ¹³C‐UBT cutoff was set at 3.0‰δPDB. Using PCR as the gold standard, the sensitivity of ¹³C‐UBT and immunohistochemistry was 96.6 and 72.4%, respectively, while the specificity was 85.7 and 95.2%, respectively. Conclusions: ¹³C‐UBT was shown to be a reliable method for the detection of H. pylori infection in C57BL/6 mice and was even more accurate than immunohistochemistry. The use of ¹³C‐UBT in the mouse model of H. pylori infection can be very useful to detect the bacterium without the need to kill the animals in long‐term time course studies.     

13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a systematic review and meta-analysis

Background: The ¹³C‐urea breath test (¹³C‐UBT) is a safe, noninvasive and reliable method for diagnosing H. pylori infection in adults. However, the test has shown variable accuracy in the pediatric population, especially in young children. We aimed to carry out a systematic review and meta‐analysis to evaluate the performance of the ¹³C‐UBT diagnostic test for H. pylori infection in children. Methods: We conducted a systematic review of the PubMed, Embase and Liliacs databases including studies from January 1998 to May 2009. Selection criteria included studies with at least 30 children and reporting the comparison of ¹³C‐UBT against a gold standard for H. pylori diagnosis. Thirty‐one articles and 135 studies were included for analysis. Children were stratified in subgroups of <6 and ≥6 years of age, and we considered variables such as type of meal, cutoff value, tracer dose, and delta time for the analysis. Discussion: The ¹³C‐UBT performance meta‐analyses showed 1, good accuracy in all ages combined (sensitivity 95.9%, specificity 95.7%, LR+ 17.4, LR? 0.06, diagnostic odds ratio (DOR) 424.9), 2, high accuracy in children >6 years (sensitivity 96.6%, specificity 97.7%, LR+ 42.6, LR? 0.04, DOR 1042.7), 3, greater variability in accuracy estimates and on average a few percentage points lower, particularly specificity, in children ≤6 years (sensitivity 95%, specificity 93.5%, LR+ 11.7, LR? 0.12, DOR 224.8). Therefore, the meta‐analysis shows that the ¹³C‐UBT test is less accurate for the diagnosis of H. pylori infection in young children, but adjusting cutoff value, pretest meal, and urea dose, this accuracy can be improved.     

First-time urea breath tests performed at home by 36,629 patients: a study of Helicobacter pylori prevalence in primary care

Background: The aim of the current study was (1) to describe the use of a ¹³C‐urea breath test (UBT) that was performed by patients at their homes as a part of a test‐and‐treat strategy in primary care and (2) to investigate the prevalence of Helicobacter pylori in patients taking a first‐time UBT. Material and Methods: The patients performed UBTs at home based on the discretion of the general practitioner and mailed the breath bags to a central laboratory for analysis. Each patient was identified by a unique civil registration number. The study was population‐based, and the background population was approximately 700,000 people. Results: From 2003 to 2009, 44,487 UBTs were performed. Of these, 36,629 were first‐time UBTs. In total, 726 of 45,213 breath bags received (1.6%) were unable to be analyzed because of errors with the bags. For both women and men who were ≤45 years of age, positive H. pylori declined over the time course of the study (women: 19.6% in 2003 to 17.6% in 2009, p < .01; men: 20.7% in 2003 to 16.9% in 2009, p < .001). Patients who were older than 45 years had significantly higher positive H. pylori results than younger patients. Conclusions: A test‐and‐treat system was possible to implement that allowed patients to perform UBTs at their homes. The results of the first‐time UBTs demonstrated that approximately one of five patients who presented with dyspepsia in the clinical setting of Danish primary care was infected with H. pylori.     

Presence of Helicobacter pylori in a Sibling is Associated with a Long‐Term Increased Risk of H. pylori Infection in Israeli Arab Children

Background and Objectives: We examined the dynamics of Helicobacter pylori infection between pre‐school and school ages and compared the determinants of late acquisition of H. pylori infection with determinants of early and persistent H. pylori infection. Methods: ELISA was used to detect H. pylori antigens in stool specimens collected from children at preschool age (3–5 years) and from their mothers and siblings in 2004. The children were tested again for H. pylori at school age (6–9 years) in 2007–2009. Household and socioeconomic characteristics were obtained by interviews. Results: The prevalence of H. pylori infection increased from 49.7% (95% CI 42.8, 56.7) in 2004 to 58.9% (95% CI 51.8, 65.6) in 2007–2009. Among children tested in both examinations, 69 (49.3%) had persistent infection, 14 (10.0%) were new cases, 56 (40.0%) remained uninfected, and one (0.7%) had lost H. pylori infection. The approximate annual incidence of infection during 2004–2009 was 5%. Sibling’s H. pylori positivity at baseline increased the risk for late acquisition of H. pylori infection; adjusted prevalence ratio (PR) 4.62 (95% CI 0.76, 28.23) (p = .09), while maternal education lowered the risk; adjusted PR 0.84 (95% CI 0.69, 1.01) (p = .06). Sibling’s H. pylori positivity was the only significant variable associated with early and persistent H. pylori infection in multivariate analysis. Conclusions: Most H. pylori infections are acquired at preschool age and transient infection beyond this age is uncommon in this population. Helicobacter pylori‐infected siblings are the major reservoir of H. pylori in early and late childhood demonstrating sustained intra‐familial transmission of H. pylori.