Conditions of malaria transmission in Dakar from 2007 to 2010

Malaria Journal

Research

Birane Cissé¹  Abdoulaye Gaye²  Cheikh Sokhna²  Libasse Gadiaga²  Jean-François Trape²  Jean-Pierre Lacaux³  Fanny Jarjaval⁴  Frédéric Pagès⁴  Lydie Godefroy⁴  Vanessa Machault⁵  Christophe Rogier⁶ 

[1] Ecole Doctorale Eau, Qualité et Usages de l'Eau (EDEQUE), Université Cheikh Anta DIOP, Dakar, Sénégal;Institut de Recherche pour le Développement, UMR 198;, Unité Mixte de Recherche 6236 (URMITE), BP 1386, Route des Pères Maristes, Dakar, Sénégal;Observatoire Midi-Pyrénées, Laboratoire d'Aérologie, Centre National de la Recherche Scientifique, Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France;Unité Mixte de Recherche 6236 (URMITE), Institut de Recherche Biomédicale des Armées, Allée du Médecin colonel Jamot, BP 60109, Parc du Pharo, 13262, Marseille cedex 07, France;Unité Mixte de Recherche 6236 (URMITE), Institut de Recherche Biomédicale des Armées, Allée du Médecin colonel Jamot, BP 60109, Parc du Pharo, 13262, Marseille cedex 07, France;Centre National d'Etudes Spatiales - Service Applications et Valorisation, 18 avenue Edouard Belin, 31401, Toulouse Cedex 9, France;Observatoire Midi-Pyrénées, Laboratoire d'Aérologie, Centre National de la Recherche Scientifique, Université Paul Sabatier, 14 avenue Edouard Belin, 31400, Toulouse, France;Unité Mixte de Recherche 6236 (URMITE), Institut de Recherche Biomédicale des Armées, Allée du Médecin colonel Jamot, BP 60109, Parc du Pharo, 13262, Marseille cedex 07, France;Institut Pasteur de Madagascar, B.P. 1274, 101, Ambatofotsikely, Antananarivo, Madagascar;

关键词: Anopheles;    Dakar;    malaria;    entomology;    Plasmodium;    Human Biting Rate;   

DOI  :  10.1186/1475-2875-10-312

 received in 2011-06-20, accepted in 2011-10-21,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundPrevious studies in Dakar have highlighted the spatial and temporal heterogeneity of Anopheles gambiae s.l. biting rates. In order to improve the knowledge of the determinants of malaria transmission in this city, the present study reports the results of an extensive entomological survey that was conducted in 45 areas in Dakar from 2007 to 2010.MethodsWater collections were monitored for the presence of anopheline larvae. Adult mosquitoes were sampled by human landing collection. Plasmodium falciparum circumsporozoïte (CSP) protein indexes were measured by ELISA (enzyme-linked immunosorbent assay), and the entomological inoculation rates were calculated.ResultsThe presence of anopheline larvae were recorded in 1,015 out of 2,683 observations made from 325 water collections. A water pH of equal to or above 8.0, a water temperature that was equal to or above 30°C, the absence of larvivorous fishes, the wet season, the presence of surface vegetation, the persistence of water and location in a slightly urbanised area were significantly associated with the presence of anopheline larvae and/or with a higher density of anopheline larvae. Most of the larval habitats were observed in public areas, i.e., freely accessible.A total of 496,310 adult mosquitoes were caught during 3096 person-nights, and 44967 of these specimens were identified as An.gambiae s.l. The mean An. gambiae s.l. human-biting rate ranged from 0.1 to 248.9 bites per person per night during the rainy season. Anopheles arabiensis (93.14%), Anopheles melas (6.83%) and An. gambiae s.s. M form (0.03%) were the three members of the An. gambiae complex. Fifty-two An. arabiensis and two An. melas specimens were CSP-positive, and the annual CSP index was 0.64% in 2007, 0.09% in 2008-2009 and 0.12% in 2009-2010. In the studied areas, the average EIR ranged from 0 to 17.6 infected bites per person during the entire transmission season.ConclusionThe spatial and temporal heterogeneity of An. gambiae s.l. larval density, adult human-biting rate (HBR) and malaria transmission in Dakar has been confirmed, and the environmental factors associated with this heterogeneity have been identified. These results pave the way for the creation of malaria risk maps and for a focused anti-vectorial control strategy.

【 授权许可】

CC BY   
© Gadiaga et al; licensee BioMed Central Ltd. 2011