Age-Related Changes in Malaria Clinical Phenotypes During Infancy Are Modified by Sickle Cell Trait.
Clin Infect Dis
; 73(10): 1887-1895, 2021 11 16.
Article
em En
| MEDLINE
| ID: mdl-33738485
ABSTRACT
BACKGROUND:
Infants are protected against Plasmodium falciparum malaria. Mechanisms that drive this protection remain unclear due to a poor understanding of malaria clinical phenotypes during infancy.METHODS:
We enrolled a birth cohort of 678 infants in Busia, Uganda, an area of high malaria transmission. We followed infants through 12 months of age and quantified protection against parasitemia and clinical disease.RESULTS:
Symptomatic malaria incidence increased from 1.2 to 2.6 episodes per person-year between 0 and <6 months and between 6 and 12 months of age, while the monthly probability of asymptomatic parasitemia given infection decreased from 32% to 21%. Sickle cell trait (HbAS) was protective against symptomatic malaria (incidence rate ratio â =â 0.57 comparing HbAS vs hemoglobin AA (HbAA); 95% confidence interval, 0.44-0.74; Pâ <â .001), but age modified this relationship (Pintâ =â <0.001), with nonlinear protection that waned between 0 and 9 months of age before increasing. Increasing age was associated with higher parasite densities at the time of infection and, in infants with HbAS, a reduced ability to tolerate high parasite densities without fever.CONCLUSIONS:
Age-dependent changes in HbAS protective efficacy in infancy were accompanied by differential loss of antiparasite and antidisease protection among HbAS and HbAA infants. This provides a framework for investigating the mechanisms that underlie infant protection against malaria. CLINICAL TRIALS REGISTRATION NCT02793622.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Traço Falciforme
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Malária Falciparum
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Malária
Limite:
Humans
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Infant
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article