A Scoping Review of the Associations Between Ascariasis, Helicobacter pylori Infection and Gastric Pathologies.

Ascaris infection-ascariasis-is the most common human parasitic worm infection worldwide and induces damage and cellular changes within the stomach. Helicobacter pylori is a bacterium of the stomach that also causes gastric pathologies globally. Importantly, Ascaris, H. pylori, and gastric diseases all disproportionately affect individuals in resource-limited settings. However, the associations between ascariasis, H. pylori infection, and gastric diseases remain relatively unexplored. We synthesized the existing research associating Ascaris infection with H. pylori infection and/or gastric pathologies. Records were identified in OVID Medline, Embase and Web of Science using search terms for ascariasis, H. pylori infection, and gastric abnormalities and additional citation searching. Blinded screening and extraction were performed by two independent reviewers. We found 410 unique citations, of which 86 (21.0%) were included. A total of 24 articles (27.9%) associated ascariasis with H. pylori infection, 68 (79.1%) associated ascariasis with gastric abnormalities, and 6 (7.0%) associated ascariasis with both H. pylori infection and gastric abnormalities. Although predominantly comprised of case reports and observational studies, these data supported significant co-endemicity of ascariasis and H. pylori infection, co-infections with both pathogens, and concurrency of ascariasis with gastric pathologies in human and non-human host organisms. The available literature thus supports associations between ascariasis, H. pylori infections, and gastric pathology, warranting further epidemiologic and mechanistic studies.