Research

Spatial distribution of the chromosomal forms of anopheles gambiae in Mali

Nafomon Sogoba^1,2 , Penelope Vounatsou² , Magaran M Bagayoko³ , Seydou Doumbia¹ , Guimogo Dolo¹ , Laura Gosoniu² , Sékou F Traoré¹ , Thomas A Smith² and Yéya T Touré⁴

¹Malaria Research and Training Center, Faculté de Médecine, de Pharmacie et d'Ondoto-Stomatologie, Université de Bamako, BP. 1805, Bamako, Mali

²Department of Public Health and Epidemiology, Swiss Tropical Institute, P.O. Box, CH-4002, Basel, Switzerland

³Vector Biology and Control, WHO Regional Office for Africa WR/Gabon, PO Box 820, Libreville, Gabon

⁴Special programme for Research and Training in Tropical Diseases (TDR), World Health Organization, CH-1211 Geneva, Switzerland

author email corresponding author email

Malaria Journal 2008, 7:205doi:10.1186/1475-2875-7-205

Published:	10 October 2008

Abstract

Background

Maps of the distribution of malaria vectors are useful tools for stratification of malaria risk and for selective vector control strategies. Although the distribution of members of the Anopheles gambiae complex is well documented in Africa, a continuous map of the spatial distribution of the chromosomal forms of An. gambiae s.s. is not yet available at country level to support control efforts.

Methods

Bayesian geostatistical methods were used to produce continuous maps of the spatial distribution of the chromosomal forms of An. gambiae s.s. (Mopti, Bamako, Savanna and their hybrids/recombinants) based on their relative frequencies in relation to climatic and environmental factors in Mali.

Results

The maps clearly show that each chromosomal form favours a particular defined eco-climatic zone. The Mopti form prefers the dryer northern Savanna and Sahel and the flooded/irrigated areas of the inner delta of the Niger River. The Savanna form favours the Sudan savanna areas, particularly the South and South-Eastern parts of the country (Kayes and Sikasso regions). The Bamako form has a strong preference for specific environmental conditions and it is confined to the Sudan savanna areas around urban Bamako and the Western part of Sikasso region. The hybrids/recombinants favour the Western part of the country (Kayes region) bordering the Republic of Guinea Conakry.

Conclusion

The maps provide valuable information for selective vector control in Mali (insecticide resistance management) and may serve as a decision support tool for the basis for future malaria control strategies including genetically manipulated mosquitoes.