title: A molecular survey of acute febrile illnesses reveals Plasmodium vivax infections in Kedougou, southeastern Senegal.
abstract: BACKGROUND
  Control efforts towards malaria due to Plasmodium falciparum significantly decreased the incidence of the disease in many endemic countries including Senegal. Surprisingly, in Kedougou (southeastern Senegal) P. falciparum malaria remains highly prevalent and the relative contribution of other Plasmodium species to the global malaria burden is very poorly documented, partly due to the low sensitivity of routine diagnostic tools. Molecular methods offer better estimate of circulating Plasmodium species in a given area. A molecular survey was carried out to document circulating malaria parasites in Kedougou region.
  
  
  METHODS
  A total of 263 long-term stored sera obtained from patients presenting with acute febrile illness in Kedougou between July 2009 and July 2013 were used for malaria parasite determination. Sera were withdrawn from a collection established as part of a surveillance programme of arboviruses infections in the region. Plasmodium species were characterized by a nested PCR-based approach targeting the 18S small sub-unit ribosomal RNA genes of Plasmodium spp.
  
  
  RESULTS
  Of the 263 sera screened in this study, Plasmodium genomic DNA was amplifiable by nested PCR from 62.35% (164/263) of samples. P. falciparum accounted for the majority of infections either as single in 85.97% (141/164) of Plasmodium-positive samples or mixed with Plasmodium ovale (11.58%, 19/164) or Plasmodium vivax (1.21%, 2/164). All 19 (11.58%) P. ovale-infected patients were mixed with P. falciparum, while no Plasmodium malariae was detected in this survey. Four patients (2.43%) were found to be infected by P. vivax, two of whom were mixed with P. falciparum. P. vivax infections originated from Bandafassi and Ninefesha villages and concerned patients aged 4, 9, 10, and 15 years old, respectively. DNA sequences alignment and phylogenetic analysis demonstrated that sequences from Kedougou corresponded to P. vivax, therefore confirming the presence of P. vivax infections in Senegal.
  
  
  CONCLUSIONS
  The results confirm the high prevalence of P. falciparum in Kedougou and provide the first molecular evidence of P. vivax infections in Senegal. These findings pave the ways for further investigations of P. vivax infections in Senegal and its contribution to the global burden of malaria disease before targeted strategies can be deployed.
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. mniang@pasteur.sn.
authors.forename: Makhtar
authors.initials: M
authors.lastname: Niang
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. latygayethiam@rocketmail.com.|Department of Animal Biology, Cheikh Anta Diop University of de Dakar, Dakar, Senegal. latygayethiam@rocketmail.com.
authors.forename: Laty Gaye
authors.initials: LG
authors.lastname: Thiam
authors.affiliation: Arbovirus and Viral Haemorrhagic Fevers Unit, Pasteur Institute of Dakar, Dakar, Senegal. asow@pasteur.sn.
authors.forename: Abdourahmane
authors.initials: A
authors.lastname: Sow
authors.affiliation: Arbovirus and Viral Haemorrhagic Fevers Unit, Pasteur Institute of Dakar, Dakar, Senegal. cloucoubar@pasteur.sn.
authors.forename: Cheikh
authors.initials: C
authors.lastname: Loucoubar
authors.affiliation: Arbovirus and Viral Haemorrhagic Fevers Unit, Pasteur Institute of Dakar, Dakar, Senegal. nsbob@pasteur.sn.
authors.forename: Ndeye Sakha
authors.initials: NS
authors.lastname: Bob
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. fdiop@pasteur.sn.
authors.forename: Fode
authors.initials: F
authors.lastname: Diop
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. bdiouf@pasteur.sn.
authors.forename: Babacar
authors.initials: B
authors.lastname: Diouf
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. oniass@pasteur.sn.
authors.forename: Oumy
authors.initials: O
authors.lastname: Niass
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. mansourouannick@yahoo.fr.
authors.forename: Annick
authors.initials: A
authors.lastname: Mansourou
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. lvarela@pasteur.sn.
authors.forename: Marie Louise
authors.initials: ML
authors.lastname: Varela
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. Perraut@pasteur.sn.
authors.forename: Ronald
authors.initials: R
authors.lastname: Perraut
authors.affiliation: Arbovirus and Viral Haemorrhagic Fevers Unit, Pasteur Institute of Dakar, Dakar, Senegal. asall@pasteur.sn.
authors.forename: Amadou A
authors.initials: AA
authors.lastname: Sall
authors.affiliation: Immunology Unit, Pasteur Institute of Dakar, Dakar, Senegal. atoure@pasteur.sn.
authors.forename: Aissatou
authors.initials: A
authors.lastname: Toure-Balde
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000097:blood / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D008288:Malaria / Q000453:epidemiology / Q000469:parasitology; D016780:Malaria, Vivax / Q000453:epidemiology* / Q000469:parasitology*; D008297:Male; D008875:Middle Aged; D010961:Plasmodium / Q000235:genetics; D010966:Plasmodium vivax / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D012675:Senegal / Q000453:epidemiology; D055815:Young Adult
chemical_list: D016054:DNA, Protozoan