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Background The incidence of ‘true’ re-infection with Helicobacter pylori after successful eradication remains uncertain. Aim To determine the worldwide rates, risk factors and clinical implications of ‘true’ re-infection of Helicobacter pylori. ‘True’ re-infection of H. pylori is defined as the situation where tests for H. pylori infection, which were negative for 12 months after eradication, become positive again at a later stage. Results Thirty six studies were identified through a literature search to be able to produce annual rates of ‘true’ re-infection, and data from 33 original articles were considered reliable and adequate in the further review. Generally, the reported rates varied from 0% to 23.4% in adults and from 1.9% to 9.6% in children. Most studies from developed countries reported rates of less than 1%, whereas relatively higher rates were reported in most of the developing countries. Small sample sizes included in the studies appeared to be associated with increased re-infection rates. Interfamilial transmission is the major cause of re-infection, although iatrogenic re-infection through contaminated endoscopic equipment has been reported. Conclusion Helicobacter pylori re-infection is not a concern in a clinical setting, especially in the developed world; however, caution must be exercised in most developing countries. [ABSTRACT FROM AUTHOR]

: Recent studies suggest that theHelicobacter pylorieradication rate in patients with non-ulcer dyspepsia is lower when compared to patients with peptic ulcer diseases.: The aim of this study was to study the efficacy of triple therapy forH. pyloriinfection in patients with duodenal ulcer vs. patients with non-ulcer dyspepsia.: A total of 582 Chinese patients with provenH. pyloriinfection were recruited to receive: omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg all given twice daily for 7 days (OCA regime). Endoscopy with rapid urease test, histology and culture were performed before treatment. Post-treatmentH. pyloristatus was determined by13C-urea breath test. Metronidazole, clarithromycin and amoxicillin resistance was defined as minimum inhibitory concentration (MIC) of>8 μg/mL,>1 μg/mL and>1 μg/mL, respectively.: A significantly higher (intention-to-treat/per-protocol) eradication rate was found in patients with duodenal ulcer than those with non-ulcer dyspepsia (91/94% vs. 84/88% respectively,P = 0.011 andP = 0.016). Clarithromycin resistance rate was higher in patients with non-ulcer dyspepsia than those with duodenal ulcer (14% vs. 6%,P = 0.015). Clarithromycin resistance (40% vs. 5%,P < 0.001, OR 12, 95% CI: 5.7–24.3) and the diagnosis of non-ulcer dyspepsia (91% vs. 84%,P = 0.011, OR 2.0, 95% CI: 1.2–3.3) significantly affected the success ofH. pylorieradication.: Clarithromycin resistance accounts for the significantly lower and suboptimalH. pylorieradication rate of OCA regimen in Chinese patients with non-ulcer dyspepsia compared to those with duodenal ulcer. [ABSTRACT FROM AUTHOR]

: The performance of commercialHelicobacter pyloridiagnostic kits developed for particular geographic regions has often been found to be of poor diagnostic value when applied to other regions, possibly because of infections being caused by differentH. pyloristrains in different regions.: To evaluate the performance of an IgG2 anti-H. pylorienzyme-linked immunoassay test (Helirad Alert) for detection ofH. pyloriinfection in both Australian and Hong Kong (Chinese) subjects.: Serum samples were tested forH. pylorispecific IgG2 and IgG antibodies by enzyme-linked immunoassay kits using identical antigen preparation in 168 Australian and 160 Hong Kong (Chinese) subjects diagnosed with dyspepsia.: Using a cut-off value determined by analysis ofH. pylori-negative Australian samples, the sensitivity, specificity and accuracy of the IgG2 assay were 77.8, 97.4 and 91.1%, respectively, for the Australian samples and 96.3, 83.8 and 90% for Hong Kong samples. For the IgG assay, sensitivity, specificity and accuracy were 87.0, 99.1 and 95.2% for Australian samples and 97.5, 75 and 86.3% for Hong Kong samples respectively. Receiver-operating characteristic analysis showed better discrimination ofH. pyloristatus when the IgG2 assay was applied to Hong Kong samples, while the IgG assay was better in the Australian samples.: These data demonstrate that the Helirad Alert enzyme-linked immunoassay could provide a reliable method for screeningH. pyloriinfection in both western and Chinese populations. [ABSTRACT FROM AUTHOR]

Summary Background : Recently, a rapid-release 100-mg 13 C-urea tablet with citrate supplement (Diabact UBT) showed excellent performance in a European population. Aim : To investigate the accuracy of a 50-mg tablet-based 13 C-urea breath test protocol. Methods : Consecutive dyspeptic patients referred for upper endoscopy were recruited. 13 C-Urea breath test was performed using a 50-mg 13 C-urea tablet (Diabact UBT) and compared with the gold standard (rapid urease test and histology). Baseline, 10-min, 20-min and 30-min breath samples were collected in all cases. The cut-off values at each measurement interval were determined by three standard deviations above the mean excess δ 13 CO2 excretion of Helicobacter pylori -negative patients. Results : Two hundred patients (150 before therapy and 50 after therapy) were available for analysis, with a mean age of 48.4 years, and 99 patients (50%) were H. pylori positive. The sensitivity and specificity of the 50-mg tablet-based 13 C-urea breath test at 10 min, 20 min and 30 min were 100% and 98%, 100% and 100%, and 100% and 98%, respectively. Conclusion : A 20-min, 50-mg tablet-based 13 C-urea breath test (Diabact UBT) protocol is highly accurate for the diagnosis of H. pylori infection. [ABSTRACT FROM AUTHOR]

Background: We have previously shown that the 75 mg 13C-urea breath test without citrate test meal is highly accurate for the diagnosis of Helicobacter pylori infection in Chinese subjects. A lower dose 50 mg 13C-urea breath test protocol with a sampling time at 20 min has not been validated previously. Aim: To investigate the accuracy of a 20-min 50 mg 13C-urea breath test protocol in Chinese subjects. Methods: Consecutive dyspeptic patients referred for upper endoscopy were recruited. 13C-urea breath test was performed using (a) 75 mg and 50 mg of 13C-urea on two separate days without a test meal, and (b) 50 mg of 13C-urea with 2.4 g citrate as test meal, and compared with the gold standard [rapid urease test (CLO test) and histology]. Baseline, 20-min and 30-min breath samples were collected in all cases. Results: Two hundred and six patients were tested. The accuracy of the 50 mg 13C-urea breath test (no citrate) at 20 min and 30 min was 98%, comparable to that of the 50 mg 13C-urea breath test with citrate (99.1%) and the 75 mg 13C-urea breath test without citrate (100%). Conclusions: A 20-min 50 mg 13C-urea breath test without citrate produced highly accurate results for the diagnosis of Helicobacter pylori infection and is more economical and convenient for the Chinese population. [ABSTRACT FROM AUTHOR]