Risk Markers of COVID-19, a Study from South-Lebanon

Background: COVID-19, caused by the novel coronavirus SARS-CoV-2, was declared by WHO in early 2020 as a worldwide pandemic. Several known risk markers are associated with COVID-19 morbidity and mortality, including age, gender, and diseases, such as hypertension, diabetes, and chronic cardiovascular diseases. Recent studies have shown an association between COVID-19 infection and the ABO blood groups. Objective: To assess the prevalence of SARS-CoV-2 among suspected COVID-19 patients as well as the risk markers for COVID-19 associated with ABO blood group, Rhesus factor, and patient's address during the past year. Methods: 69,019 nasopharyngeal swab samples were collected and analyzed by reverse transcription polymerase chain reaction technique for the detection of SARS-CoV-2 in patients attending a tertiary health care center in South Lebanon during the period between August 2020 and July 2021. Results: Among all tested subjects, the prevalence of SARS-CoV-2 infection was 19.2% (95% CI: 18.9% to 19.5%). Among those with known blood group (N = 17,462), odds of SARS-CoV-2 were higher in group A (Odds Ratio = 1.12, 95% CI: 1.02 to 1.23) and group AB (OR = 1.19, 95% CI: 1.00 to 1.41) relative to the reference group O (OR = 1). Odds of SARS-CoV-2 in the Rh-negative group (OR = 1.02, 95% CI: 0.89 to 1.16) were not significantly different from the Rh-positive group. Among those with known address (N = 30,060), odds of SARS-CoV-2 were lower in residents of remote areas (OR = 0.89, 95% CI: 0.80 to 0.99) relative to central cities. Conclusion: There is a modestly higher risk of SARS-CoV-2 infection associated with blood groups A and AB, and a lower risk associated with living in remote, less crowded regions.