Association of the ABO blood groups with falciparum malaria in the malaria endemic county of Busia in western Kenya

Abstract

Background The interplay between malaria parasites and blood group antigens remains a fascinating subject with potential to contribute to the development of new interventions to reduce the global burden of malaria. Elucidation of the association between the erythrocyte ABO antigens status and infection with Plasmodium falciparum can bring about understanding of the differences noted in the ABO blood group variation in malaria endemic areas. Objective To determine the ABO distribution among patients and its association with malaria infection in the malaria endemic county of Busia in western Kenya. Hypothesis The study hypothesized that during infection with P falciparum, group O offers a survival advantage, group A confers a disadvantage, and group B has an intermediate. Design This was a cross-sectional study that sequentially enrolled patients who were suspected to have malaria, and had their blood tested for the malaria parasite and the ABO blood group status.Study site The Busia county referral hospital Method Upon giving their consent, a total of 246 febrile patients who were clinically examined and suspected to have malaria had their blood tested for the malaria parasite by making thick and thin blood smears and observing under the microscope at 100x. Parasitaemia was determined for patients to tested positive for P.falciparum. The patients’ blood groups were determined using the tube technique. The variables used in the study questionnaire were age, gender, ABO blood group status, malaria blood slide examination result and clinical diagnosis of the study subjects. Data entry was done in MS excel, database management and analysis was done using Statistical Package for Social and Sciences (SPSS) version 13 software. Results Of the 246 respondents, 63.8% of them were aged below 5 years of age and 28.9% were above 16 years. 60.5% of the respondents were females. Both age (X2=0.997 p>0.05) and sex (X2=0.975 p>0.05) were however not significantly associated with disease status. 44.31% (109) of the respondents were blood group O, 26% (64) were blood A and 24.4% (60) were blood group B. Only 5.3% (13) were blood group AB. More than one thirds 37.8% (93) of the respondents were MPs positive. All the respondents had less than 1000 parasites /µ L of blood. Blood group was not statistically associated (X2=2.857, p=0.827) with parasitaemia. Malaria infection showed significant association with blood group A (X2=4.736, p<0.05), B (X2=0.570, p<0.015) and AB (X2=2.751, p<0.05). Blood group O was not statistically associated with getting malaria infection(X2=0.005, p>0.05). Conclusion During infection with P.falciparum, blood group O individuals are conferred with a protective advantage, group A individuals are at a disadvantage, while blood group B has an intermediate effect.