ABO and Plasmodium falciparum malaria: Thus, effect of the ABO blood group on uncomplicated P. falciparum infection would be better investigated with comparison groups consisting of asymptomatic falciparum malaria cases rather than who are uninfected (or healthy normal) with Plasmodium. Only two studies included in this review compared odds of uncomplicated P. falciparum infection to asymptomatic P. falciparum infection by blood groups [43, 56].