Limits...
Gametocytaemia after drug treatment of asymptomatic Plasmodium falciparum.

Dunyo S, Milligan P, Edwards T, Sutherland C, Targett G, Pinder M - PLoS Clin Trials (2006)

Bottom Line: Gametocyte carriage (the area under the curve of gametocyte density versus time), was reduced by 71% in the SP group, and by 74% in the SP+AS group, compared to placebo.Gametocyte carriage varied with age and was greater among children under 15 than among adults.Effective treatment of asexual parasitaemia in the dry season reduces gametocyte carriage to very low levels after 4 wk.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Laboratories, Banjul, Gambia.

ABSTRACT

Objectives: Treatment of Plasmodium falciparum malaria with sulfadoxine-pyrimethamine (SP) is followed by a sharp rise in the prevalence and density of gametocytes. We did a randomized trial to determine the effect of treatment of asymptomatic infections with SP or SP plus one dose of artesunate (SP+AS) on gametocyte carriage.

Design: The study was a three-arm open-label randomized trial. We randomized asymptomatic carriers of P. falciparum to receive antimalarial treatment or placebo, and recorded the prevalence and density of gametocytes over the next 2 mo.

Setting: The trial was conducted during the dry (low malaria transmission) season in four rural villages in Gambia.

Participants: Participants were adults and children aged over 6 mo with asexual P. falciparum infection and confirmed free of clinical symptoms of malaria over a 2-d screening period.

Interventions: Participants were randomized to receive a single dose of SP or SP+AS or placebo.

Outcome measures: The outcome measures were the presence of gametocytes 7 and 56 d after treatment, and the duration and density of gametocytaemia over 2 mo.

Results: In total, 372 asymptomatic carriers were randomized. Gametocyte prevalence on day 7 was 10.5% in the placebo group, 11.2% in the SP group (risk difference to placebo 0.7%, 95% confidence interval -7.4% to 8.7%, p = 0.87), and 7.1% in the SP+AS group (risk difference to placebo 4.1%, 95% confidence interval -3.3% to 12%, p = 0.28). By day 56, gametocyte prevalence was 13% in the placebo group and 2% in both drug-treated groups. Gametocyte carriage (the area under the curve of gametocyte density versus time), was reduced by 71% in the SP group, and by 74% in the SP+AS group, compared to placebo. Gametocyte carriage varied with age and was greater among children under 15 than among adults.

Conclusions: Treatment of asymptomatic carriers of P. falciparum with SP does not increase gametocyte carriage or density. Effective treatment of asexual parasitaemia in the dry season reduces gametocyte carriage to very low levels after 4 wk.

No MeSH data available.


Related in: MedlinePlus

Prevalence of Asexual Parasitaemia and Gametocytes after Treatment(A) Prevalence of asexual parasitaemia over the 2 mo following treatment. The profile for the 39 clinical cases, who were treated with SP+AS, is also shown.(B) Prevalence of gametocytes.(C) Prevalence of gametocytes in the subset of participants who were gametocyte negative on D0.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1851719&req=5

pctr-0010020-g003: Prevalence of Asexual Parasitaemia and Gametocytes after Treatment(A) Prevalence of asexual parasitaemia over the 2 mo following treatment. The profile for the 39 clinical cases, who were treated with SP+AS, is also shown.(B) Prevalence of gametocytes.(C) Prevalence of gametocytes in the subset of participants who were gametocyte negative on D0.

Mentions: Asexual parasite clearance was similar in the SP and SP+AS groups (Figure 3A). Gametocyte rates in the SP and placebo groups were similar on D3, D7, and D14. On D7, the prevalence of gametocyte carriage was 10.5% in the placebo group and 11.2% in the SP group (risk difference 0.7%, 95% CI −7.4% to 8.7%, p = 0.87), and 7.1% in the SP+AS group (difference between SP+AS and SP groups, 4.1%, 95%CI −3.3% to 12%, p = 0.28). Gametocyte prevalence showed a steady decline in the active drug treatment groups, and by D28, gametocyte prevalence was less than 3% in the SP and SP+AS groups (Figure 3B). In contrast, gametocyte prevalence in the clinical cases had increased by D3. The AUC index of gametocyte carriage (Table 3) was 62 in the placebo group; treatment with SP reduced this index to 18 (a 71% reduction, p < 0.001, Kruskal-Wallis test), and addition of AS reduced this index to 16 (a 74% reduction from the value in the placebo group, p < 0.001, and only slightly lower than the SP group, p = 0.02). In the clinical cases, the AUC gametocyte index was 147, significantly greater than the asymptomatic group treated with the same drug regimen (p = 0.02) but not significantly different from the placebo group (p = 0.32).


Gametocytaemia after drug treatment of asymptomatic Plasmodium falciparum.

Dunyo S, Milligan P, Edwards T, Sutherland C, Targett G, Pinder M - PLoS Clin Trials (2006)

Prevalence of Asexual Parasitaemia and Gametocytes after Treatment(A) Prevalence of asexual parasitaemia over the 2 mo following treatment. The profile for the 39 clinical cases, who were treated with SP+AS, is also shown.(B) Prevalence of gametocytes.(C) Prevalence of gametocytes in the subset of participants who were gametocyte negative on D0.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1851719&req=5

pctr-0010020-g003: Prevalence of Asexual Parasitaemia and Gametocytes after Treatment(A) Prevalence of asexual parasitaemia over the 2 mo following treatment. The profile for the 39 clinical cases, who were treated with SP+AS, is also shown.(B) Prevalence of gametocytes.(C) Prevalence of gametocytes in the subset of participants who were gametocyte negative on D0.
Mentions: Asexual parasite clearance was similar in the SP and SP+AS groups (Figure 3A). Gametocyte rates in the SP and placebo groups were similar on D3, D7, and D14. On D7, the prevalence of gametocyte carriage was 10.5% in the placebo group and 11.2% in the SP group (risk difference 0.7%, 95% CI −7.4% to 8.7%, p = 0.87), and 7.1% in the SP+AS group (difference between SP+AS and SP groups, 4.1%, 95%CI −3.3% to 12%, p = 0.28). Gametocyte prevalence showed a steady decline in the active drug treatment groups, and by D28, gametocyte prevalence was less than 3% in the SP and SP+AS groups (Figure 3B). In contrast, gametocyte prevalence in the clinical cases had increased by D3. The AUC index of gametocyte carriage (Table 3) was 62 in the placebo group; treatment with SP reduced this index to 18 (a 71% reduction, p < 0.001, Kruskal-Wallis test), and addition of AS reduced this index to 16 (a 74% reduction from the value in the placebo group, p < 0.001, and only slightly lower than the SP group, p = 0.02). In the clinical cases, the AUC gametocyte index was 147, significantly greater than the asymptomatic group treated with the same drug regimen (p = 0.02) but not significantly different from the placebo group (p = 0.32).

Bottom Line: Gametocyte carriage (the area under the curve of gametocyte density versus time), was reduced by 71% in the SP group, and by 74% in the SP+AS group, compared to placebo.Gametocyte carriage varied with age and was greater among children under 15 than among adults.Effective treatment of asexual parasitaemia in the dry season reduces gametocyte carriage to very low levels after 4 wk.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Laboratories, Banjul, Gambia.

ABSTRACT

Objectives: Treatment of Plasmodium falciparum malaria with sulfadoxine-pyrimethamine (SP) is followed by a sharp rise in the prevalence and density of gametocytes. We did a randomized trial to determine the effect of treatment of asymptomatic infections with SP or SP plus one dose of artesunate (SP+AS) on gametocyte carriage.

Design: The study was a three-arm open-label randomized trial. We randomized asymptomatic carriers of P. falciparum to receive antimalarial treatment or placebo, and recorded the prevalence and density of gametocytes over the next 2 mo.

Setting: The trial was conducted during the dry (low malaria transmission) season in four rural villages in Gambia.

Participants: Participants were adults and children aged over 6 mo with asexual P. falciparum infection and confirmed free of clinical symptoms of malaria over a 2-d screening period.

Interventions: Participants were randomized to receive a single dose of SP or SP+AS or placebo.

Outcome measures: The outcome measures were the presence of gametocytes 7 and 56 d after treatment, and the duration and density of gametocytaemia over 2 mo.

Results: In total, 372 asymptomatic carriers were randomized. Gametocyte prevalence on day 7 was 10.5% in the placebo group, 11.2% in the SP group (risk difference to placebo 0.7%, 95% confidence interval -7.4% to 8.7%, p = 0.87), and 7.1% in the SP+AS group (risk difference to placebo 4.1%, 95% confidence interval -3.3% to 12%, p = 0.28). By day 56, gametocyte prevalence was 13% in the placebo group and 2% in both drug-treated groups. Gametocyte carriage (the area under the curve of gametocyte density versus time), was reduced by 71% in the SP group, and by 74% in the SP+AS group, compared to placebo. Gametocyte carriage varied with age and was greater among children under 15 than among adults.

Conclusions: Treatment of asymptomatic carriers of P. falciparum with SP does not increase gametocyte carriage or density. Effective treatment of asexual parasitaemia in the dry season reduces gametocyte carriage to very low levels after 4 wk.

No MeSH data available.


Related in: MedlinePlus