Systematic review on the zoonotic potential of Helicobacter pylori

The high global prevalence of Helicobacter pylori infection has sparked interest in determining whether the bacterium has zoonotic capacity. This systematic review aims to evaluate the zoonotic capacity of H. pylori, identify potential routes of transmission, and analyze its public health significance. This study follows the PRISMA guidelines. The search was conducted on April 15th 2024 in three data bases: Web of Science, Scopus, and PubMed. No restriction on the time of publication was applied. Inclusion criteria covered original articles on the bacterium in domestic, farm, and wild animals, as well as those examining animal products and water as transmission routes. Exclusion criteria included research on different bacteria of the same genus, non-animal food sources, and articles not in English or Spanish. A total of 393 studies were initially retrieved. After removing duplicates, 284 unique studies remained. Following a screening process based on titles, abstracts, and full texts, 28 studies met the inclusion criteria and were selected for analysis in this review. Results indicate that H. pylori in pets (dogs and cats mainly) does not seem to have zoonotic potential, but these animals may act as reservoirs. Furthermore, farm animals have been identified as potential vectors through direct contact with heavily contaminated environments. Additionally, raw milk has been suggested as a possible transmission route, and flies in these environments might also play a role in spreading the bacteria. The presence of H. pylori in both freshwater and saltwater environments suggests that water and fish might also play a role in its transmission. In conclusion, the significant public health implications of this bacterium highlight the need for further research to better understand these transmission pathways and their impact, as there seems to be evidence that in some environments with animals there may be a risk of zoonotic diseases.