title: 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 random-effects 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.
authors.affiliation: Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran. f_sayehmiri@yahoo.com.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sayehmiri
authors.forename: Faezeh
authors.initials: F
authors.lastname: Kiani
authors.forename: Kourosh
authors.initials: K
authors.lastname: Sayehmiri
authors.forename: Setareh
authors.initials: S
authors.lastname: Soroush
authors.forename: Khairollah
authors.initials: K
authors.lastname: Asadollahi
authors.forename: Mohammad Yousef
authors.initials: MY
authors.lastname: Alikhani
authors.forename: Ali
authors.initials: A
authors.lastname: Delpisheh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Emaneini
authors.forename: Lidija
authors.initials: L
authors.lastname: Bogdanović
authors.forename: Ali Mohammad
authors.initials: AM
authors.lastname: Varzi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Zarrilli
authors.forename: Morovat
authors.initials: M
authors.lastname: Taherikalani
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis / Q000235:genetics*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics*; D005756:Gastritis / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007492:Iran / Q000453:epidemiology; D010437:Peptic Ulcer / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D015995:Prevalence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori