title: Role of Helicobacter pylori cagA EPIYA motif and vacA genotypes for the development of gastrointestinal diseases in Southeast Asian countries: a meta-analysis.
abstract: BACKGROUND
  Infection with cagA-positive, cagA EPIYA motif ABD type, and vacA s1, m1, and i1 genotype strains of Helicobacter pylori is associated with an exacerbated inflammatory response and increased risk of gastroduodenal diseases. However, it is unclear whether the prevalence and virulence factor genotypes found in Southeast Asia are similar to those in Western countries. Here, we examined the cagA status and prevalence of cagA EPIYA motifs and vacA genotypes among H. pylori strains found in Southeast Asia and examined their association with gastroduodenal disease.
  
  
  METHODS
  To determine the cagA status, cagA EPIYA motifs, and vacA genotypes of H. pylori, we conducted meta-analyses of 13 previous reports for 1,281 H. pylori strains detected from several Southeast Asian countries.
  
  
  RESULTS
  The respective frequencies of cagA-positive and vacA s1, m1, and i1 genotypes among examined subjects were 93% (1,056/1,133), 98% (1,010/1,033), 58% (581/1,009), and 96% (248/259), respectively. Stratification showed significant variation in the frequencies of cagA status and vacA genotypes among countries and the individual races residing within each respective country. The frequency of the vacA m-region genotype in patients infected with East Asian-type strains differed significantly between the northern and southern areas of Vietnam (p < 0.001). Infection with vacA m1 type or cagA-positive strains was associated with an increased risk of peptic ulcer disease (odds ratio: 1.46, 95%CI: 1.01-2.12, p = 0.046 and 2.83, 1.50-5.34, p = 0.001, respectively) in the examined Southeast Asian populations.
  
  
  CONCLUSIONS
  Both Western- and East Asian-type strains of H. pylori are found in Southeast Asia and are predominantly cagA-positive and vacA s1 type. In Southeast Asia, patients infected with vacA m1 type or cagA-positive strains have an increased risk of peptic ulcer disease. Thus, testing for this genotype and the presence of cagA may have clinical usefulness.
authors.affiliation: First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Sahara
authors.forename: Mitsushige
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Ratha-Korn
authors.initials: RK
authors.lastname: Vilaichone
authors.forename: Varocha
authors.initials: V
authors.lastname: Mahachai
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Miyajima
authors.forename: Takahisa
authors.initials: T
authors.lastname: Furuta
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001210:Asia, Southeastern / Q000453:epidemiology; D001426:Bacterial Proteins / Q000235:genetics*; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D006801:Humans; D017720:Molecular Epidemiology; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori