Prevalence and Diagnostic Comparison of and Non- Infections in Patients Undergoing Upper Gastrointestinal Endoscopy with Gastric Biopsy in Algarve, Portugal.

infects over half of the global population and is associated with various gastric and extra-gastric diseases. Other species, such as zoonotic non- Helicobacters (NHPHs), have shown similar associations with gastritis and MALT lymphoma and -negative cases with gastric disease have been identified, including gastric MALT lymphoma, chronic gastritis, and gastroduodenal ulcers. Accurate identification of these species is of great relevance but remains challenging using conventional diagnostic methods. This cross-sectional study aimed to determine the prevalence of and NHPH infections, comparing standard histological protocols with molecular techniques. Between December 2024 and February 2025, 54 adult patients undergoing upper gastrointestinal endoscopy (UGE) with gastric biopsy in three hospitals in Algarve, Portugal were recruited. Endoscopic assessment was performed, and gastric biopsies were collected for histological and molecular analysis. DNA was extracted from antral biopsies and analyzed by conventional PCR to detect and NHPH. diagnostic techniques were compared, descriptive plus statistical analysis was performed, and -values < 0.05 were considered to be statistically significant. Fifty-four patients were included in the study, with 51.9% of them presenting symptoms. Endoscopic gastritis was observed in 66.7% of patients, while histological gastritis was present in 88.9%, with statistically significant differences between the two diagnostic techniques ( = 0.004). spp. were identified in 44.4% (24/54) of the patients. was detected in 42.6% of the patients by Modified Giemsa stain and in 33.3% by PCR. was found in 35.9% of the patients, with 22.2% showing mixed infections. This study reveals a significant prevalence of spp. in patients from the Algarve region, with both and zoonotic detected. This is the first report of DNA detection in gastric biopsies via PCR from patients undergoing UGE in Portugal, highlighting the need to consider NHPH in clinical diagnosis. It is important to include molecular methods in routine diagnostics and the need for broader studies to assess regional and national trends in infections besides