TY - JOUR

T1 - Specific and nonspecific responses to Plasmodium falciparum blood-stage parasites and observations on the gametocytemia in schoolchildren living in a malaria-endemic area of Mozambique

AU - Hogh, B

AU - Thompson, R

AU - Hetzel, C

AU - Fleck, S L

AU - Kruse, N A

AU - Jones, I

AU - Dgedge, M

AU - Barreto, J

AU - Sinden, R E

PY - 1995/1

Y1 - 1995/1

N2 - We have observed specific and nonspecific reactivities to the asexual states and gametocytes of Plasmodium falciparum and examined the effect of chloroquine and Fansidar (pyrimethamine/sulfadoxine) on the dynamics of gametocytemia. Schoolchildren peripheral blood films positive for P. falciparum gametocytes were identified in a malaria-endemic area of Mozambique. The children were randomly allocated into two groups to receive chloroquine or pyrimethamine/sulfadoxine, and were followed for 28 days after treatment. In patients harboring drug-sensitive parasites, asexual parasitemias were cleared by day 4, but gametocytes persisted for an additional 17 days. The prevalence of the asexual parasites was 67.6% in the chloroquine-treated group at day 0 and 61.1% at day 28, whereas in the pyrimethamine/sulfadoxine treated group, the initial parasite prevalence of 70.7% was reduced to 2.4% at day 28, suggesting a high prevalence of chloroquine-resistant parasites. On day 0, gametocyte prevalence was 59.5% in the chloroquine-treated group and in 68.3% in the pyrimethamine/sulfadoxine-treated group; these values were reduced to 5.6% and 2.4%, respectively, at day 28. Our results suggest strongly that there is no induction of gametocytogenesis by either course of chemotherapy.

AB - We have observed specific and nonspecific reactivities to the asexual states and gametocytes of Plasmodium falciparum and examined the effect of chloroquine and Fansidar (pyrimethamine/sulfadoxine) on the dynamics of gametocytemia. Schoolchildren peripheral blood films positive for P. falciparum gametocytes were identified in a malaria-endemic area of Mozambique. The children were randomly allocated into two groups to receive chloroquine or pyrimethamine/sulfadoxine, and were followed for 28 days after treatment. In patients harboring drug-sensitive parasites, asexual parasitemias were cleared by day 4, but gametocytes persisted for an additional 17 days. The prevalence of the asexual parasites was 67.6% in the chloroquine-treated group at day 0 and 61.1% at day 28, whereas in the pyrimethamine/sulfadoxine treated group, the initial parasite prevalence of 70.7% was reduced to 2.4% at day 28, suggesting a high prevalence of chloroquine-resistant parasites. On day 0, gametocyte prevalence was 59.5% in the chloroquine-treated group and in 68.3% in the pyrimethamine/sulfadoxine-treated group; these values were reduced to 5.6% and 2.4%, respectively, at day 28. Our results suggest strongly that there is no induction of gametocytogenesis by either course of chemotherapy.

KW - Adolescent

KW - Animals

KW - Antibodies, Protozoan/blood

KW - Antigens, Protozoan/immunology

KW - Antimalarials/pharmacology

KW - Blotting, Western

KW - C-Reactive Protein/analysis

KW - Child

KW - Chloroquine/pharmacology

KW - Computer Simulation

KW - Drug Combinations

KW - Drug Resistance

KW - Enzyme-Linked Immunosorbent Assay

KW - Fluorescent Antibody Technique

KW - Haptoglobins/analysis

KW - Humans

KW - Luminescent Measurements

KW - Malaria, Falciparum/drug therapy

KW - Models, Biological

KW - Mozambique/epidemiology

KW - Parasitemia/drug therapy

KW - Plasmodium falciparum/drug effects

KW - Prevalence

KW - Pyrimethamine/pharmacology

KW - Recombinant Proteins/immunology

KW - Sulfadoxine/pharmacology

M3 - Journal article

C2 - 7856825

VL - 52

SP - 50

EP - 59

JO - Journal. National Malaria Society

JF - Journal. National Malaria Society

SN - 0002-9637

IS - 1

ER -