1. In vivo parasitological measures of artemisinin susceptibility.
- Author
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Stepniewska K, Ashley E, Lee SJ, Anstey N, Barnes KI, Binh TQ, D'Alessandro U, Day NP, de Vries PJ, Dorsey G, Guthmann JP, Mayxay M, Newton PN, Olliaro P, Osorio L, Price RN, Rowland M, Smithuis F, Taylor WR, Nosten F, and White NJ
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Drug Resistance, Endemic Diseases, Humans, Infant, Kaplan-Meier Estimate, Malaria, Falciparum epidemiology, Malaria, Falciparum transmission, Middle Aged, Parasitemia drug therapy, Parasitemia epidemiology, Parasitemia transmission, Recurrence, Antimalarials therapeutic use, Artemisinins therapeutic use, Malaria, Falciparum drug therapy, Malaria, Falciparum parasitology, Parasitemia parasitology, Plasmodium falciparum drug effects
- Abstract
Parasite clearance data from 18,699 patients with falciparum malaria treated with an artemisinin derivative in areas of low (n=14,539), moderate (n=2077), and high (n=2083) levels of malaria transmission across the world were analyzed to determine the factors that affect clearance rates and identify a simple in vivo screening measure for artemisinin resistance. The main factor affecting parasite clearance time was parasite density on admission. Clearance rates were faster in high-transmission settings and with more effective partner drugs in artemisinin-based combination treatments (ACTs). The result of the malaria blood smear on day 3 (72 h) was a good predictor of subsequent treatment failure and provides a simple screening measure for artemisinin resistance. Artemisinin resistance is highly unlikely if the proportion of patients with parasite densities of <100,000 parasites/microL given the currently recommended 3-day ACT who have a positive smear result on day 3 is <3%; that is, for n patients the observed number with a positive smear result on day 3 does not exceed (n + 60)/24.
- Published
- 2010
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