Submicroscopic Plasmodium falciparum infections before and after sulfadoxine-pyrimethamine and artesunate association treatment in Dienga, Southeastern Gabon.
BACKGROUND
It has been shown that Plasmodium falciparum submicroscopic infections (SMI) can contribute to malaria-associated anemia as well as to cerebral malaria. Polymerase chain reaction (PCR) assays are usually used as an alternative to microscopy in detecting subpatently infected individuals.


OBJECTIVE
The main objective of this study was to investigate the occurrence of SMI before and after a suppressive antimalarial treatment in the population of the village of Dienga in Gabon.


METHODS
Nested PCR was used to detect SMI and to determine genotypes.


RESULTS
The prevalence rates of SMI were 13.67% (38/278) at day 0 and 8.99% (25/278) at day 14 after sulfadoxine-pyrimethamine-artesunate treatment. Genotype analysis of two polymorphic regions of the merozoite surface protein (MSP)-1 block 2, MSP-2 and a dimorphic region of the erythrocyte binding antigen (EBA-175) revealed that as many as 88% (22/25) of SMI detected after treatment were completely new alleles, indicating either previously sequestered parasites or newly acquired infections.


CONCLUSIONS
These results demonstrate the usefulness of sulfadoxine-pyrimethamine-artesunate association treatment in the population of Dienga and confirmed early parasite genotype change after a suppressive antimalarial treatment in endemic areas.
Touré
Fousseyni S
FS
Centre International de Recherches Médicales de Franceville (CIRMF), BP 769 Franceville, Gabon. fousseyni@yahoo.fr
Mezui-Me-Ndong
Jérôme
J
Ouwe-Missi-Oukem-Boyer
Odile
O
Ollomo
Benjamin
B
Mazier
Dominique
D
Bisser
Sylvie
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D037621:Artemisinins / Q000627:therapeutic use*; D000077332:Artesunate; D016054:DNA, Protozoan / Q000097:blood / Q000235:genetics; D004338:Drug Combinations; D005681:Gabon; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000188:drug therapy* / Q000469:parasitology; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011739:Pyrimethamine / Q000627:therapeutic use*; D012717:Sesquiterpenes / Q000627:therapeutic use*; D013413:Sulfadoxine / Q000627:therapeutic use*
D000962:Antimalarials; D037621:Artemisinins; D016054:DNA, Protozoan; D004338:Drug Combinations; D012717:Sesquiterpenes; C001205:fanasil, pyrimethamine drug combination; D000077332:Artesunate; D013413:Sulfadoxine; D011739:Pyrimethamine