Perfil epidemiológico e manifestações clínicas associadas a genes de virulência da bactéria Helicobacter pylori em biópsias gástricas de pacientes submetidos à endoscopia digestiva alta

Abstract

Objectives: To characterize the epidemiological profile and clinical manifestations of individuals with Helicobacter pylori infection in the gastric mucosa, to determine the prevalence of the pathogen’s virulence gene cagA, and to investigate associations between bacterial strains, epidemiological characteristics, and symptomatology. Methods: A cross-sectional study was conducted in Passo Fundo, south of Brazil. Adults aged ≥ 18 years of both sexes who underwent upper gastrointestinal endoscopy at a regional hospital and had H. pylori infection confirmed by histopathological analysis of gastric biopsy specimens were included. Participants completed an epidemiological questionnaire, and infected tissue samples were analyzed for the presence of H. pylori cagA gene using conventional polymerase chain reaction (PCR). Statistical analysis included frequency distribution of descriptive variables, prevalence estimates for gene positivity, and association analyses with 95% confidence intervals. Results: The final sample comprised 40 patients selected from 225 individuals, yielding an H. pylori infection prevalence of 17.8% in the study population. The sample was predominantly female (70.0%), aged ≥ 50 years (65.0%), residing in urban areas (87.5%), living with ≥ 3 household members (52.5%), with current or previous tobacco use (52.5%) and alcohol consumption (70.0%). All participants were symptomatic, with heartburn (77.5%) and abdominal and epigastric pain (62.5% each) being the most prevalent complaints. Molecular analysis revealed that 52.5% of participants were positive for the cagA gene. There was no statistically significant relation between H. pylori strains that were positive or negative for the cagA gene and the clinical-epidemiological factors evaluated. Conclusion: This study demonstrated a low prevalence of H. pylori infection, consistent with the regional variability reported in the literature. The characterization of the sample and the frequency of cagA-positive strains were in agreement with current evidence. Despite the use of gold-standard molecular detection methods, the sampling strategy and relatively small sample size may have limited the statistical power of the study. Considering the sample and the methodology employed, it can be concluded that the presence of the cagA virulence gene in the gastric mucosa is not related with the clinical and epidemiological profile of infected individuals.