PLASMODIUM FALCIPARUM INFECTIONS AMONG INDIVIDUALS WITH DIFFERENT ABO BLOOD GROUPS ATTENDING KIPKELION AND FORT-TENAN HOSPITALS IN KERICHO COUNTY, KENYA

Sigei Jonah*, Dr. Kamau Lucy and Dr. Mwangi Erick

ABSTRACT

Objectives: The study was designed: (i) to determine the prevalence level of Plasmodium falciparum infections among individuals with different ABO and Rhesus blood group phenotypes; (ii) to determine the relationship between levels of P. falciparum parasitaemia and ABO blood groups; (iii) to determine the relationship between levels of parasitaemia and age of patient; and (iv) to determine how P. falciparum infections compare in relation to sex. Methods: Blood samples from patients with clinical symptoms of malaria were microscopically analyzed for confirmation of P. falciparum parasites. Both thick and thin blood films were prepared from the blood samples of each patient. The remaining portion of blood was used for determination of blood group using commercial antisera –A, B and D and observing for agglutination. Results: Microscopic examination of blood slides showed that 169 patients were malaria positive and 137 were negative out of the total 306 patients sampled. P. falciparum prevalence level in Kipkelion west district were 32.5% for blood group A+, 22.5% for blood group B+, 20.1% for blood group O+ while O- individuals had no infections by microscopy. P. falciparum infection had significant and positive association with blood types A+ (χ2=10.38, d.f=1, p=0.001), B+ (χ2=2.68, d.f=1, p=0.049) and AB+ (χ2=1.98, d.f=1, p=0.003). Regression analysis showed a strong positive relationship between age category and parasitaemia levels (r2 = 0.945, F=481.7, d.f=6, p=0.001). Chi-square revealed significant difference between mean P. falciparum parasitaemia in blood groups A+ (χ2=13.39, d.f=1, p=0.001), B+ (χ2=6.78, d.f=1, p=0.001) and AB+ (χ2=2.95, d.f=1, p=0.086). Chi-square revealed a positive association between Rhesus positive individuals and P. falciparum infections (χ2 = 80.6, df= 2, p= 0.0001) while Rhesus negative individuals showed lack of association with P. falciparum infections (χ2 = 445.2, df= 2, p= 0.067). Conclusion: Individual’s blood group can predispose or confer resistance to P. falciparum infection as evidenced in the results of the current study which suggest that individuals with blood groups A+, B+ and AB+ are more susceptible to P. falciparum infections than individuals with blood groups A-, B-, O- and O+. Also individual’s age category is a risk factor to acquiring P. falciparum infection.

Keywords: Plasmodium falciparum, parasitaemia, EDTA.