effects of abo blood groups and helicobacter pylori on covid-19 susceptibility and disease severity: findings from a cross-sectional analysis

Background: the investigation of the correlation between abo blood groups and susceptibility to infectiousdiseases, particularly covid-19 and helicobacter pylori (h. pylori), has garnered significant scholarlyattention in recent studies. this study aimed to evaluate the association between abo blood groups and h.pylori infection with covid-19 susceptibility and severity.methods: this cross-sectional study was conducted from october 1, 2021 to march 31, 2023. during thisperiod, serum samples from 1,105 patients diagnosed with covid-19 at hospitals affiliated with shirazuniversity of medical sciences were analyzed for sars-cov-2 and h. pylori antibodies using the enzymelinkedimmunosorbent assay (elisa) technique. clinical data, including demographic characteristics andmanifestations of covid-19, were collected through structured interviews and comprehensive reviews ofmedical records.results: the prevalence of covid-19 was significantly higher among individuals with blood group acompared to other groups (p=0.032). patients co-infected with h. pylori had more severe covid-19 symptoms(p=0.021). the findings from this investigation reveal that blood group o is correlated with an increased riskfor both covid-19 and h. pylori infections, whereas blood group ab demonstrates a reduced susceptibility tocovid-19, although this does not imply definitive protective. noteworthy associations were identified betweenabo blood groups and specific covid-19 symptoms, including headache, chronic underlying conditions,chest discomfort, and sore throat. the hospitalization among patients with blood group ab was higher thanthat observed in other blood groups (10.8%), while it was notably lower in patients with blood group o (4.6%,p=0.038).conclusion: our findings suggest a significant association between abo blood groups, h. pylori infection, andsusceptibility to covid-19. these factors may contribute to disease severity and warrant further investigationfor potential clinical implications.