Prevalence of Malaria Parasitaemia and its Association with ABO Blood Group in Jos, Nigeria

Abstract

Malaria is a disease associated with high morbidity and mortality especially among children and other high risk groups. Certain ABO blood group is thought to be protective of severe malaria. Determining the prevalence of malaria parasitaemia among asymptomatic individuals and its association with ABO blood grouping could be a step to further studies to understand the immunity of Malaria. A cross sectional study in which one hundred and seven asymptomatic, consenting individuals in malaria endemic Jos, Nigeria, were recruited into the study. Demographic data and blood samples were taken for the determination of ABO blood group and for thin and thick blood film for malaria parasite detection. The asexual parasite density (asp/μl) was also determined. Of the 107 individuals studied, there were 30(28.0%) males and 77(72.0%) females. The mean age of study participants was 26.2±6.3 years. The predominant blood group was O 48(44.9%), followed by B 33(30.8%), A 21(19.6%) and AB 5(4.7%) respectively. The prevalence of Malaria parasitaemia was 40(37.4%). The mean parasite density was 241.0± 69 asp/μl. There was a significant association between Malaria parasitaemia and ABO blood group (P<0.017). The prevalence among the same blood group was: A 12(57.1%); O 21(48.8%); AB 1(20.0%) and B 6(18.2%) respectively. Across the ABO blood groups, females were significantly parasitaemic as compared to males (P> 0.016, 0.03 and 0.026 respectively) The median WBC count of Malaria infected individuals was significantly higher than the median WBC count of those subjects without parasitaemia, (P<0.01). There was a positive correlation between the total White blood cell count (WBC) count and asexual parasite density, although only 35.4% was attributable to the WBC (r²=0.354, P<0.0001). In conclusion, the prevalence of Malaria parasitaemia in our cohort is comparatively low to southern parts of Nigeria. Although there was relative spread of parasitaemia across all blood groups, the highest rate was observed among blood group A and in females. We recommend that available malaria interventions should be directed at all individuals but with particular emphasis on Blood group A and females. Large studies are required to validate our findings, and to elucidate the socio-demographic and immunologic mechanisms involved in the apparent protection.