title: Malaria in three epidemiological strata in Mauritania.
abstract: BACKGROUND
  Malaria epidemiology in Mauritania has been characterized on the basis of epidemiological strata, defined by climatic and geographic features, which divide the country into three zones: Sahelian zone, Sahelo-Saharan transition zone, and Saharan zone. The association between geographic stratification and malaria transmission was assessed through a series of parasitological and entomological surveys.
  
  
  METHODS
  Surveys were conducted during the 'cool' dry season in 2011, 'hot' dry season in 2012, and rainy season in 2013 in a total of 12 sentinel sites. Finger-prick capillary blood samples were collected from children aged 2-9 years old in randomly selected households for microscopic examination and rapid diagnostic test for malaria. Adult mosquitoes were sampled by pyrethrum spray catch and CDC light traps and identified using morphological keys and molecular tools.
  
  
  RESULTS
  Of 3445 children included, 143 (4.15 %) were infected with malaria parasites including Plasmodium falciparum (n = 71, 2.06 %), Plasmodium vivax (57, 1.65 %), P. falciparum-P. vivax (2, 0.06 %), Plasmodium ovale (12, 0.35 %), and Plasmodium malariae (1, 0.03 %). A large majority of P. falciparum infections were observed in the Sahelo-Saharan zone. Malaria prevalence (P < 0.01) and parasite density (P < 0.001) were higher during the rainy season (2013), compared to cool dry season (2011). Plasmodium vivax was mainly observed in the Saharan region [43 of 59 (73 %) P. vivax infections], mostly in Nouakchott districts, with no significant seasonal variation. Of 3577 mosquitoes captured, 1014 (28.3 %) belonged to Anopheles spp. Anopheles gambiae was the predominant species in all three epidemiological strata during the 'cool' dry season in 2011 but was absent in all study sites, except for Teyarett district in Nouakchott, during the 'hot' dry season in 2012. During the rainy season in 2013, An. gambiae, Anopheles arabiensis, Anopheles pharoensis, and Anopheles rufipes were abundant in different zones.
  
  
  CONCLUSIONS
  The results of the present study support the stratification of malaria in Mauritania. However, the Sahelian zone had the lowest malaria prevalence, while the Sahelo-Saharan zone had the highest malaria burden. Local changes due to anthropogenic factors (i.e., human migration, urbanization, malaria interventions) should be considered in order to optimize the control strategy.
authors.affiliation: Initiative mauritanienne pour la lutte contre les maladies endémiques « MEDCINGO » , ilôt 358, Riyad Pk8, Nouakchott, Mauritania. hmoukah2002@yahoo.fr.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ouldabdallahi Moukah
authors.affiliation: Laboratoire de parasitologie-mycologie, Institut National de Recherches en Santé Publique (INRSP), B.P. 695, Nouakchott, Mauritania.
authors.forename: Ousmane
authors.initials: O
authors.lastname: Ba
authors.affiliation: Laboratoire de parasitologie-mycologie, Institut National de Recherches en Santé Publique (INRSP), B.P. 695, Nouakchott, Mauritania.
authors.forename: Hampaté
authors.initials: H
authors.lastname: Ba
authors.affiliation: Programme National de Lutte contre le Paludisme (PNLP), Ministère de la Santé, Nouakchott, Mauritania.
authors.forename: Mohamed Lemine
authors.initials: ML
authors.lastname: Ould Khairy
authors.affiliation: Laboratoire d'Ecologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques, Université Cheikh Anta Diop (UCAD), Dakar, Senegal.
authors.forename: Ousmane
authors.initials: O
authors.lastname: Faye
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Faculté de Médecine La Timone, Institut de Recherche pour le Développement (IRD) 198, Aix-Marseille Université, Marseille, France.|Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France.|Laboratoire de Parasitologie, Centre National de Référence du Paludisme région Antilles-Guyane, Institut Pasteur de la Guyane, 23 avenue Pasteur, BP 6010, 97306, Cayenne cedex, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Bogreau
authors.affiliation: Unité Mixte de Recherche MIVEGEC  « Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle » , Institut de Recherche pour le Développement (IRD) 224-Centre National de la Recherche Scientifique 5290, Université de Montpellier (UM), 911 avenue Agropolis, 34394, Montpellier cedex 5, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Simard
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), Faculté de Médecine La Timone, Institut de Recherche pour le Développement (IRD) 198, Aix-Marseille Université, Marseille, France.|Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France.
authors.forename: Leonardo K
authors.initials: LK
authors.lastname: Basco
mesh_terms: D063147:Animal Distribution; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D002980:Climate; D004777:Environment; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D008288:Malaria / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission*; D008297:Male; D008435:Mauritania / Q000453:epidemiology; D010961:Plasmodium / Q000302:isolation & purification*; D011156:Population Density; D015995:Prevalence; D012621:Seasons
keywords: Anopheles; Drug resistance; Epidemiology; Mauritania; Plasmodium; Prevalence