Prevalence of cagA and vacA among Helicobacter pylori-infected patients in Iran: a systematic review and meta-analysis

Abstract

The varieties of infections caused by Helicobacter pylori may be due to differences in bacterial genotypes and virulence factors as well as environmental and host-related factors. This study aimed to investigate the prevalence of cagA and vacA genes among H. pylori-infected patients in Iran and analyze their relevance to the disease status between two clinical groups via a meta-analysis method. Different databases including PubMed, ISI, Scopus, SID, Magiran, Science Direct, and Medlib were investigated, and 23 relevant articles from the period between 2001 and 2012 were finally analyzed. The relevant data obtained from these papers were analyzed by a randomeffects model. Data were analyzed using R software and STATA. The prevalence of cagA and vacA genes among H. pylori-infected patients was 70% (95% CI, 64-75) and 41% (95% CI, 24.3-57.7), respectively. The prevalence of duodenal ulcers, peptic ulcers, and gastritis among cagA+ individuals was 53% (95% CI, 20-86), 65% (95% CI, 34-97), and 71% (95% CI, 59-84), respectively. Odds ratio (OR) between cagA-positive compared with cagA-negative patients showed a 1.89 (95% CI, 1.38-2.57) risk of ulcers. In conclusion, the frequency of cagA gene among H. pylori strains is elevated in Iran and it seems to be more frequently associated with gastritis. Therefore, any information about cagA and vacA prevalence among different H. pylori-infected clinical groups in the country can help public health authorities to plan preventive policies to reduce the prevalence of diseases associated with H. pylori infection.

Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients

“…Overall H. pylori prevalence did not differ between potential- and active-CD patients (both nearly 30–40%); however among infected subjects, the presence of cagA + strains was significantly associated with milder histological damage (Marsh 0–1). Prevalence of cagA + H. pylori strains vary between populations between 40 and 80% (Feliciano et al, 2015 ; O'Ryan et al, 2015 ; Sayehmiri et al, 2015 ; Scarpulla et al, 2015 ) and could explain at least in part the difference observed between our study and previous findings. The presence/absence of the cagA + gene among infecting H. pylori strains is a factor that may be modulating the severity of duodenal lesions.…”

Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies

“…Some authors indicate that gastric reflux is not the only route by which H. pylori reaches the mouth and its detection and the genotyping in mouth and in stomach are complementary tests to understand some epidemiological issues (21) . Therefore, any information about cagAandbabA2genotypes prevalence among different H. pylori-infected clinical groups in the country can help public health authorities to plan preventive policies to reduce the prevalence of diseases associated with H. pylori infection (32) . The aim of this work was to detect and correlate the virulence markers cagA and babaA2 of H. pylori in gastric biopsies and oral cavity samples.…”

What is the Relationship Between Helicobacter Pylori CagA Genotypes and Gastrointestinal Diseases in the Iranian Population? A Systematic Review and Meta-Analysis

“…The encoding gene of CagA toxin (s120-140 kDa), cagA gene, is one of the most important genes in the H. pylori whole genome, and locates in cag pathogenicity islands (cag-PAIs). The presence and expression of cagA gene is related with gastric complications such gastritis, peptic ulcer, gastric polyps, precancerous status, cell survival and gastric adenocarcinoma (14)(15). Studies in China, Japan, and South Korea showed that 90% of isolated strains from patients had cagA gene in their genome (16)(17)(18)(19)(20).…”