The Impact of Sequestration on Artemisinin-Induced Parasite Clearance in Plasmodium falciparum Malaria in Africa.
Clin Infect Dis
; 76(9): 1585-1593, 2023 05 03.
Article
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| MEDLINE
| ID: mdl-36519341
ABSTRACT
BACKGROUND:
Artemisinin-resistant Plasmodium falciparum is spreading in Southeast Asia and Africa. In vivo susceptibility to artemisinin is studied by looking at the rate of decline of peripheral parasitemia (parasite clearance half-life). However, parasites that are adhered/sequestered to the endothelium and undetectable in the peripheral blood are not considered in the estimation of parasite clearance. Here, we evaluated the influence of sequestration on in vivo artemisinin efficacy in Uganda, where artemisinin resistance is spreading.METHODS:
We analyzed 133 patients with P. falciparum malaria included in an in vivo study on artemisinin efficacy in northern Uganda in 2018 and 2019. The parasite clearance half-life was estimated from peripheral parasitemia after artemisinin monotherapy. P. falciparum histidine-rich protein 2 (PfHRP2) was measured in pretreatment plasma. The number of sequestered parasites was estimated from PfHRP2 concentration and peripheral parasitemia.RESULTS:
The estimated number of sequestered parasites per plasma volume ranged from 0 to 2 564 000/µL. Inflammation, thrombocytopenia, and dyslipidemia were significantly associated with sequestration independent of peripheral parasitemia. The median parasite clearance half-lives were 1.65 hours in patients infected with Pfkelch13 wild-type parasites (n = 104) and 3.95 hours in those with A675V artemisinin-resistant mutant (n = 18). In the multivariable model for the wild-type population, 1 000 000/µL of sequestered parasites were estimated to delay parasite clearance by 16.8% (95% confidence interval, 5.1%-28.5%), although it was not clear in the A675V population.CONCLUSIONS:
In patients with P. falciparum malaria without artemisinin-resistant mutations, intensive sequestration delays parasite clearance after treatment, which may contribute to reduced artemisinin efficacy.Palabras clave
Texto completo:
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Base de datos:
MEDLINE
Asunto principal:
Parásitos
/
Malaria Falciparum
/
Artemisininas
/
Antimaláricos
País/Región como asunto:
Africa
Idioma:
En
Revista:
Clin Infect Dis
Asunto de la revista:
DOENCAS TRANSMISSIVEIS
Año:
2023
Tipo del documento:
Article