Seroprevalence of Seasonal Influenza A and B and Their Association with ABO/Rh Blood Groups Among Nurses in Najran, Saudi Arabia

Abstract

Background: Influenza, caused by Orthomyxoviridae viruses, poses a significant global health threat, particularly to healthcare workers due to their occupational exposure. Objectives: The present cross-sectional study aimed to assess the prevalence of influenza A and B antibodies among nurses in Najran, Saudi Arabia, and explore potential associations with ABO and Rh blood groups. Methods: A total of 180 nurses from four healthcare facilities participated in this study conducted between January and April 2021. Demographic data were collected, and blood samples were tested for influenza immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay (ELISA). Results: A total of 158 samples were eligible for analysis due to the presence of equivocal IgG results in 22 samples. The results revealed a moderate seropositivity of influenza A and B antibodies (51.6% and 56.3%, respectively), with no significant associations observed between serological status and demographic factors such as age, gender, or nationality. Approximately 82% of the participants received the influenza vaccine, yet no significant differences in antibody levels were observed between seropositive vaccinated and unvaccinated individuals. Additionally, although trends suggested that individuals with the A+ blood group had higher antibody levels, these differences were not statistically significant. A significant negative correlation between influenza B antibody levels and age was found (r = -0.2111, P = 0.0086), and was evident within the vaccinated subgroup (r = -0.2198, P = 0.0178). Conclusions: These findings suggest that both natural immunity and vaccination contribute to the influenza serological status of healthcare workers. Further research is needed to clarify the role of blood group phenotypes in immune responses.