Artesunate reduces but does not prevent posttreatment transmission of Plasmodium falciparum to Anopheles gambiae.
Combination therapy that includes artemisinin derivatives cures most falciparum malaria infections. Lowering transmission by reducing gametocyte infectivity would be an additional benefit. To examine the effect of such therapy on transmission, Gambian children with Plasmodium falciparum malaria were treated with standard regimens of chloroquine or pyrimethamine-sulfadoxine alone or in combination with 1 or 3 doses of artesunate. The infectivity to mosquitoes of gametocytes in peripheral blood was determined 4 or 7 days after treatment. Infection of mosquitoes was observed in all treatment groups and was positively associated with gametocyte density. The probability of transmission was lowest in those who received pyrimethamine-sulfadoxine and 3 doses of artesunate, and it was 8-fold higher in the group that received pyrimethamine-sulfadoxine alone. Artesunate reduced posttreatment infectivity dramatically but did not abolish it completely. The study raises questions about any policy to use pyrimethamine-sulfadoxine alone as the first-line treatment for malaria.
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom. geoff.targett@lshtm.ac.uk
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Targett
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Drakeley
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Jawara
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von Seidlein
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R
Coleman
J
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Deen
M
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Pinder
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T
Doherty
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Sutherland
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Walraven
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Milligan
D000293:Adolescent; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D000962:Antimalarials / Q000627:therapeutic use*; D037621:Artemisinins; D000077332:Artesunate; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005714:Gambia; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000635:transmission; D010963:Plasmodium falciparum / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D011739:Pyrimethamine / Q000627:therapeutic use; D012717:Sesquiterpenes / Q000627:therapeutic use*; D013413:Sulfadoxine / Q000627:therapeutic use
D000962:Antimalarials; D037621:Artemisinins; D004338:Drug Combinations; D012717:Sesquiterpenes; D000077332:Artesunate; D013413:Sulfadoxine; D002738:Chloroquine; D011739:Pyrimethamine