Gametocytaemia in senegalese children with uncomplicated Falciparum malaria treated with chloroquine, amodiaquine or sulfadoxine plus pyrimethamine

Plasmodium falciparum gametocytaemia was studied in 266 Senegalese children (median 4 years, range 0.5-16) with uncomplicated malaria treated with chl oroquine (CQ), amodiaquine (AQ) or sulfadoxine+pyrimethamine (SP). The prop ortion of resistant infections in vivo to these drugs was 44 %, 16 % and 7 %, respectively, Gametocytes were counted by microscopy in thick smears on days 0, 4, 7 and 14 after treatment, There was a peak of gametocytaemia one week after treatment; on days 0, 7 and 14 the gametocyte prevalences were 35 %, 73 % and 63 %, and the geometric means of gametocyte densities were 1 .3, 12.5 and 5.6/mul of blood, Three factors were found to influence gameto cytaemia: treatment, efficacy of treatment, and duration of symptoms before treatment. Gametocyte prevalence and density significantly appeared higher in children treated with SP than with CQ, and higher with CQ than with AQ. Gametocyte prevalence and density were higher in resistant than in sensiti ve infections. The period between the appearance of the first clinical symp toms and treatment was positively and significantly linked to gametocyte pr evalence and density on days 0 and 4. Early treatment with AQ, against sens itive infection, was followed by the lowest gametocytaemia, By contrast, tr eatment with SP against resistant infection was followed by the highest gam etocytaemia. No clear relationship was observed between the density of asex ual stages on day 0 and the gametocytaemia of any day between days 0 and 14 . The epidemiological significance of post-therapeutic gametocytaemia and i ts possible role in the spread of resistant parasites are underlined, Solut ions are proposed in order to avoid or reduce this gametocytaemia.