Association of ABO blood groups and complicated Plasmodium falciparum malaria in Accra, Ghana

Abstract

Background: The clinical outcome of Plasmodium falciparum malaria in endemic areas is associated with erythrocyte polymor- phisms including the ABO blood groups. Studies have reported association of ABO blood group to susceptibility, resistance and severity of P. falciparum malaria infection. Individuals with blood group ‘A’ have been found to be highly susceptible to falciparum malaria whereas blood group ‘O’ is said to confer protection against complicated cases. Methods: The study was conducted between January to April 2010, at the outpatient department of the Korle-Bu teaching Hos- pital in Accra, Ghana. Five milliliters of blood sample was collected from each participant and the haemoglobin level, parasitaemia and ABO blood group of the samples collected were determined. Results: We analysed samples from 239 malaria patients and found that group O was present in 16.1% of complicated cases weighed against 40.9% of uncomplicated controls. Individuals with complicated malaria were about twice likely to be of blood group A and B than O (A vs. O, OR=1.90, 95% CI=1.59 – 2.26, P<0.0001; B vs. O, OR=1.82. 95% CI=1.57 – 2.23, P<0.0001). Blood group O participants with complicated diseases had low parasitaemia compared to the blood groups (P<0.0001). This may give blood group O individuals a survival advantage over the other groups in complicated malaria as suggested. Participants with complicated falciparum malaria were generally anaemic and younger than those with uncomplicated disease Conclusion: Blood group O offers some protection from com- plicated falciparum malaria and may possess a survival advantage over the Non-O groups.