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.

Comparison of the effect of clarithromycin triple therapy with or without N-acetylcysteine in the eradication of Helicobacter pylori: a randomized controlled trial.

BACKGROUND: Whether adjunctive N-acetylcysteine (NAC) may improve the efficacy of triple therapy in the first-line treatment of Helicobacter pylori infection remains unknown. Our aim was to compare the efficacy of 14-day triple therapy with or without NAC for the first-line treatment of H. pylori. MATERIAL AND METHODS: Between 1 January 2014 and 30 June 2018, 680 patients with H. pylori infection naïve to treatment were enrolled in this multicenter, open-label, randomized trial. Patients were randomly assigned to receive triple therapy with NAC [NAC-T14, dexlansoprazole 60 mg four times daily (q.d.); amoxicillin 1 g twice daily (b.i.d.), clarithromycin 500 mg b.i.d., NAC 600 mg b.i.d.] for 14 days, or triple therapy alone (T14, dexlansoprazole 60 mg q.d.; amoxicillin 1 g b.i.d., clarithromycin 500 mg b.i.d.) for 14 days. Our primary outcome was the eradication rates by intention to treat (ITT). Antibiotic resistance and CYP2C19 gene polymorphism were determined. RESULTS: The ITT analysis demonstrated H. pylori eradication rates in NAC-T14 and T14 were 81.7% [276/338, 95% confidence interval (CI): 77.5-85.8%] and 84.3% (285/338, 95% CI 80.4-88.2%), respectively. In 646 participants who adhered to their assigned therapy, the eradication rates were 85.7% and 88.0% with NAC-T14 and T14 therapies, respectively. There were no differences in compliance or adverse effects. The eradication rates in subjects with clarithromycin-resistant, amoxicillin-resistant, or either clarithromycin/amoxicillin resistant strains were 45.2%, 57.9%, and 52.2%, respectively, for NAC-T14, and were 66.7%, 76.9%, and 70.0%, respectively, for T14. The efficacy of NAC-T14 and T14 was not affected by CYP2C19 polymorphism. CONCLUSION: Add-on NAC to triple therapy was not superior to triple therapy alone for first-line H. pylori eradication [ClinicalTrials.gov identifier: NCT02249546].

Evaluation of surfactant flushing for remediating EDC-tar contamination.

Ethylene dichloride tar (EDC-tar) is a dense non-aqueous phase liquid (DNAPL) waste originated from the process of vinyl chloride production, with major constituents including chlorinated aliphatic and aromatic hydrocarbons. This study investigated the feasibility of Surfactant Enhanced Aquifer Remediation (SEAR) for treating EDC-tar contaminated aquifers. Initial experiments explored the potential to enhance the apparent solubility of EDC-tar using single or mixed surfactants. The results showed that an aqueous solution mixed anionic and non-ionic surfactants (i.e., SDS/Tween 80) exhibited higher EDC-tar apparent solubility and lower surface tension than other surfactant systems tested. Additionally, alkaline pH aids in increasing the EDC-tar apparent solubility. In column flushing experiments, it was seen that the alkaline mixed SDS/Tween 80 solution showed better removal of pure EDC-tar from silica sand porous media. Furthermore, separation of EDC-tar in the surfactant solution was conducted employing a salting-out effect. Significant separation of DNAPL was observed when 13 wt.% or more NaCl was added to the solution. Overall, this study evaluates the feasibility of using SEAR for remediating EDC-tar contaminated subsurface soil and groundwater.