Sickle-trait hemoglobin does not influence <i>Anopheles</i> biting rates

Abstract

Abstract Children with sickle cell trait (HbAS) are protected against severe and symptomatic Plasmodium falciparum malaria. While several within-host resistance mechanisms have been investigated, it is unknown whether this protection may be attributable in part to reductions in exposure to P. falciparum parasites via mosquito bites. In a 15-month cohort in Western Kenya, we matched mosquito bloodmeals to human hosts based on short tandem repeat (STR) genotypes to determine individual mosquito biting rates. Using a multilevel multivariable model, we assessed mosquito biting behavior with respect to human β-globin genotypes and found no significant difference in the biting rates between individuals with HbAA and HbAS genotypes (biting rate ratio (BRR): 1.23, 95% CI: 0.86 - 1.77). These findings suggest that protection from malaria conferred by sickle trait is likely not attributable to reduced exposure to infectious mosquito bites. Author Summary Sickle cell trait (HbAS) is protective against severe and symptomatic malaria. Here, we investigate whether β-globin genotype (HbAS vs HbAA) is associated with differential mosquito biting rates. In a 15-month longitudinal cohort study in Western Kenya, we matched blood meals to community members based on short tandem repeat genotyping. We found no difference in biting rates across human β-globin types, suggesting that protection from severe and symptomatic malaria conferred by sickle trait is not attributable to reduced exposure to infectious bites.