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Fig. 4 | Malaria Journal

Fig. 4

From: Malaria parasite clearance

Fig. 4

Parasite clearance following the start of anti-malarial drug treatment with an ACT in falciparum malaria. After an initial and variable lag phase, which depends on the stage of parasite development, the decline in parasitaemia is generally log linear [23, 31,32,, 32, 37, 38, 40, 42, 56, 97, 100, 122]. The rate constant of this decline, or its derivative half-life, is the best metric for the assessment of resistance to drugs acting on ring stage parasites-notably artemisinin derivatives [31, 37, 38, 40]. The simpler measure- the proportion of patients who have microscopy detectable parasitaemia on day 3 [100, 101] whilst useful for screening, is heavily dependent on starting parasite density; two infections with the same clearance half-lives (3 h) typically associated with full susceptibility to artemisinin derivative are compared with a 50-fold difference in admission parasitaemia which results in an 18-h difference in parasite clearance time. An artemisinin resistant infection (parasite clearance half-life 6 h) is shown for comparison [38]

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