[Allelic polymorphism of Plasmodium falciparum MSP-2 gene in blood samples from Gabonese children].
In this study we have undertaken the molecular analysis of the MSP-2 gene of R falciparum isolates collected from schoolchildren living in the village of Dienga (Gabon). Using conventional microscopy and the polymerase chain reaction, 61% of these children harboured parasites without any symptom of malaria (asymptomatic status). Children with a malaria episode were those with an axillary temperature > or = 37.5 degrees C and a parasitaemia > or =800 parasites/microl of blood. Comparisons of the allelic diversity and distribution of MSP-2 gene were carried out according to the clinical status at the time of sampling. Polymorphism of the MSP-2 gene was large in both clinical groups, both asymptomatic and symptomatic (11 identified alleles). The allele FC27/560bp (base pairs) was found significantly in clinical isolates. Prevalence of the 3D7 family was 68% and 44% in asymptomatic infections and clinical infections, respectively. Multiple P. falciparum genotypes were more predominant in clinical cases (2.96 clones/child with a malaria attack vs 2.01 clones/child with asymptomatic infections). We observed also a reduction of the complexity of infection beyond the age of 10 years. These results are discussed in regard to studies conducted in other areas in Africa.
Centre International de Recherches Médicales, B.P. 769, Franceville, Gabon. ffntoumi@hotmail.com
F
F
Ntoumi
J
J
Ngoundou-Landji
A J
AJ
Luty
G
G
Dubreuil
P
P
Millet
D000293:Adolescent; D000483:Alleles; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D001769:Blood / Q000469:parasitology; D002648:Child; D005260:Female; D005681:Gabon; D006801:Humans; D008297:Male; D010963:Plasmodium falciparum / Q000235:genetics*; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*
D000953:Antigens, Protozoan; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium