Plasmodium falciparum gametocytaemia in Nigerian children: before, during and after treatment with antimalarial drugs
Authors: Sowunmi, A.; Fateye, B. A.
Source: Tropical Medicine & International Health, Volume 8, Number 9, September 2003 , pp. 783-792(10)
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.
Document Type: Research Article
Affiliations: Department of Pharmacology & Therapeutics and Institute for Medical Research and Training, University of Ibadan, Ibadan, Nigeria
Publication date: September 1, 2003