title: Plasmodium falciparum gametocytaemia in Nigerian children: before, during and after treatment with antimalarial drugs.
abstract: We evaluated gametocyte carriage and intensities of gametocytaemia in 710 children presenting with acute, symptomatic, uncomplicated Plasmodium falciparum malaria who were treated with various antimalarial drug regimens: chloroquine (CQ); chloroquine plus chlorpheniramine, a histamine H1 receptor antagonist that reverses CQ resistance in P. falciparum in vitro and in vivo (CQCP); chloroquine plus ketotifen, a histamine H1 receptor antagonist that reverses CQ resistance in P. falciparum in vitro but not in vivo in the present study (CQK); chloroquine plus pyrimethamine-sulphadoxine (CQPS); amodiaquine (AQ); amodiaquine plus pyrimethamine-sulphadoxine (AQPS); and pyrimethamine-sulphadoxine (PS). On presentation, gametocyte carriage was significantly higher in CQ-resistant (CQ-R) than in CQ-sensitive (CQ-S) infections. Following CQ treatment, gametocyte carriage was significantly higher at all times after treatment and gametocyte density significantly higher on day 7 of follow-up in children with CQ-R than CQ-S infections. CQ treatment of CQ-R infections resulted in significantly higher density of gametocytaemia on day 7 compared with pre-treatment (day 0), but similar treatment of CQ-S infections resulted in significantly lower density of gametocytaemia on day 14 compared with day 0. Among children with CQ-R infections, those with mild (RI) resistance carried gametocytes significantly more often than those with moderate (RII) resistance on days 5 and 7 of follow-up (P = 0.04 and 0.01, respectively). Disposition kinetics of gametocytaemia using a non-compartmental method showed that the half life of gametocytaemia was longer and the clearance slower in children with CQ-R than in those with CQ-S infections. PS treatment was associated with significantly higher gametocyte carriage at all times between days 1 and 14, and significantly higher gametocytaemias on days 7 and 14 than in the other treatment regimens. Combination of AQ with PS significantly decreased gametocyte carriage at all times between days 1 and 14 of follow-up. Continuing use of CQ in CQ-R infections may encourage transmission of CQ-R infections; SP monotherapy is associated with significant gametocyte carriage and gametocytaemia and may encourage transmission of SP resistant infections as resistance to the drug increases.
authors.affiliation: Department of Pharmacology & Therapeutics, University of Ibadan, Ibadan, Nigeria. malaria.iba@alpha.linkserve.com
authors.forename: A
authors.initials: A
authors.lastname: Sowunmi
authors.forename: B A
authors.initials: BA
authors.lastname: Fateye
mesh_terms: D000367:Age Factors; D000655:Amodiaquine / Q000627:therapeutic use; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use; D004338:Drug Combinations; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000469:parasitology; D008297:Male; D009549:Nigeria; D018512:Parasitemia / Q000188:drug therapy*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development; D011739:Pyrimethamine / Q000627:therapeutic use; D013413:Sulfadoxine / Q000627:therapeutic use
chemical_list: D000962:Antimalarials; D004338:Drug Combinations; D000655:Amodiaquine; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D002738:Chloroquine; D011739:Pyrimethamine