Vivax malaria in Mauritania includes infection of a Duffy-negative individual
1 Unité de Recherche en Biologie et Epidémiologie Parasitaires, Institut de Recherche Biomédicale des Armées, Allée du médecin colonel Eugène Jamot, Parc du Pharo, BP 60109, 13262 Marseille Cedex 07, France
2 Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UMR 6236, Marseille, France
3 Laboratoire de Biotechnologies, Faculté des Sciences et Techniques, Université de Nouakchott, Mauritania
4 UFR Biologie et Santé, Département de Biologie, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco
5 Laboratoire Aliments, Environnement et Santé (LAES), Faculté des Sciences et Techniques, Université Cadi Ayyad, Marrakech, Morocco
6 Institut Pasteur de Madagascar, Antananarivo, Madagascar
7 Laboratoire de Paludologie, Institut de Recherche pour le Développement, Dakar, Sénégal
Malaria Journal 2011, 10:336 doi:10.1186/1475-2875-10-336Published: 3 November 2011
Duffy blood group polymorphisms are important in areas where Plasmodium vivax is present because this surface antigen is thought to act as a key receptor for this parasite. In the present study, Duffy blood group genotyping was performed in febrile uninfected and P. vivax-infected patients living in the city of Nouakchott, Mauritania.
Plasmodium vivax was identified by real-time PCR. The Duffy blood group genotypes were determined by standard PCR followed by sequencing of the promoter region and exon 2 of the Duffy gene in 277 febrile individuals. Fisher's exact test was performed in order to assess the significance of variables.
In the Moorish population, a high frequency of the FYBES/FYBES genotype was observed in uninfected individuals (27.8%), whereas no P. vivax-infected patient had this genotype. This was followed by a high level of FYA/FYB, FYB/FYB, FYB/FYBES and FYA/FYBES genotype frequencies, both in the P. vivax-infected and uninfected patients. In other ethnic groups (Poular, Soninke, Wolof), only the FYBES/FYBES genotype was found in uninfected patients, whereas the FYA/FYBES genotype was observed in two P. vivax-infected patients. In addition, one patient belonging to the Wolof ethnic group presented the FYBES/FYBES genotype and was infected by P. vivax.
This study presents the Duffy blood group polymorphisms in Nouakchott City and demonstrates that in Mauritania, P. vivax is able to infect Duffy-negative patients. Further studies are necessary to identify the process that enables this Duffy-independent P. vivax invasion of human red blood cells.