title: Red blood cell polymorphisms in relation to Plasmodium falciparum asymptomatic parasite densities and morbidity in Senegal.
abstract: Numerous studies have shown that several red blood cell polymorphisms protect against severe malaria. Such a relation is much less clear for mild malaria attacks and for the asymptomatic carriage of Plasmodium falciparum. The impact of red blood cell polymorphisms on the level of parasite density was assessed in a group of 464 Senegalese children from the Sereer ethnic group, studied for 18 months. These genetic factors were also related to the malarial morbidity, investigated during 2 successive transmission seasons among 169 of these children. The frequencies of the host genetic factors in the whole group were 0.52 for blood group O, 0.13 for hemoglobin S, 0.16 for the G6PD A-deficient variant and 0.24 for alpha+-thalassemia (-alpha(3.7) deletion). Hemoglobin S was associated with protection against mild malaria attacks. None of the genetic factors was implicated in a better control of parasite densities. These associations may be particular to this ethnic group due to the specificities of malaria endemicity in this area. The pressure exerted in the area by other non-malarial infectious diseases as well as the genetic heterogeneity of circulating parasites may also contribute to these observations.
authors.affiliation: Institut de Recherche pour le Développement (IRD), Unité de Recherche 010 Santé de la mère et de l'enfant en milieu tropical, BP 1386 Dakar, Senegal. migot@ird.fr
authors.forename: Florence
authors.initials: F
authors.lastname: Migot-Nabias
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pelleau
authors.forename: Laurence
authors.initials: L
authors.lastname: Watier
authors.forename: Juliette
authors.initials: J
authors.lastname: Guitard
authors.forename: Cécile
authors.initials: C
authors.lastname: Toly
authors.forename: Carla
authors.initials: C
authors.lastname: De Araujo
authors.forename: Mamadou I
authors.initials: MI
authors.lastname: Ngom
authors.forename: Christophe
authors.initials: C
authors.lastname: Chevillard
authors.forename: Oumar
authors.initials: O
authors.lastname: Gaye
authors.forename: André
authors.initials: A
authors.lastname: Garcia
mesh_terms: D000818:Animals; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000469:parasitology* / Q000502:physiology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood* / Q000453:epidemiology / Q000235:genetics* / Q000469:parasitology; D008297:Male; D009017:Morbidity; D010963:Plasmodium falciparum / Q000302:isolation & purification*; D011110:Polymorphism, Genetic; D012306:Risk; D012675:Senegal / Q000453:epidemiology