ABO and Rh blood groups and risk of infection: systematic review and meta-analysis

BACKGROUND: Persons with non-O and Rh-positive blood types are purported to be more susceptible to infection, including SARS-CoV-2, but there remains uncertainty about the degree to which this is so for both non-viral and viral infections. METHODS: We systematically reviewed Embase and PubMed from January 1(st) 1960 to May 31(st) 2022. English-language publications were selected that separately investigated the relation between ABO and/or Rh blood group and risk of SARS-CoV-2 and non-SARS-CoV-2 infection. Pooled odds ratios (OR(p)) and 95% confidence intervals (CI) were then generated for each. RESULTS: Non-O blood groups had a higher OR(p) for SARS-CoV-2 than O blood groups, both within 22 case–control studies (2.13, 95% CI 1.49- 3.04) and 15 cohort studies (1.89, 95% CI 1.56- 2.29). For non-SARS-CoV-2 viral infections, the respective OR(p) were 1.98 (95% CI 1.49–2.65; 4 case–control studies) and 1.87 (95% CI 1.53–2.29; 12 cohort studies). For non-viral infections, the OR(p) were 1.56 (95% CI 0.98–2.46; 13 case–control studies) and 2.11 (95% CI 1.67–6.67; 4 cohort studies). Rh-positive status had a higher OR(p) for SARS-CoV-2 infection within 6 case–control studies (13.83, 95% CI 6.18–30.96) and 6 cohort studies (19.04, 95% CI 11.63–31.17), compared to Rh-negative persons. For Rh status, non-SARS-CoV-2 infections, the OR(p) were 23.45 (95% CI 16.28–33.76) among 7 case–control studies, and 9.25 (95% CI 2.72–31.48) within 4 cohort studies. High measures of heterogeneity were notably observed for all analyses. CONCLUSIONS: Non-O and Rh-positive blood status are each associated with a higher risk of SARS-CoV-2 infection, in addition to other viral and non-viral infections. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-023-08792-x.