Climate change and altitudinal structuring of malaria vectors in south-western Cameroon: their relation to malaria transmission

Tanga, M.C.; Ngundu, W.I.; Judith, N.; Mbuh, J.; Tendongfor, N.; Simard, Frédéric; Wanji, S.

doi:10.1016/j.trstmh.2010.02.006

« Previous Next »Transactions of the Royal Society of Tropical Medicine and Hygiene
Volume 104, Issue 7 , Pages 453-460, July 2010

Climate change and altitudinal structuring of malaria vectors in south-western Cameroon: their relation to malaria transmission

M.C. Tanga
- Department of Zoology and Entomology, University of Pretoria, 0002 Pretoria, South Africa
- Corresponding author. Tel.: +254 714 56 14 93; fax: +254 20 8632001/2.
W.I. Ngundu
- Department of Zoology and Botany, University of Buea, P.O. Box 63, Buea, Cameroon
N. Judith
- Research Foundation for Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon
- Department of Zoology and Botany, University of Buea, P.O. Box 63, Buea, Cameroon
J. Mbuh
- Research Foundation for Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon
- Department of Zoology and Botany, University of Buea, P.O. Box 63, Buea, Cameroon
N. Tendongfor
- Research Foundation for Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon
- Department of Biochemistry and Microbiology, University of Buea, P.O. Box 63, Buea, Cameroon
Frédéric Simard
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la Lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
S. Wanji
- Research Foundation for Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon
- Department of Biochemistry and Microbiology, University of Buea, P.O. Box 63, Buea, Cameroon

Received 28 July 2009; received in revised form 11 February 2010; accepted 11 February 2010.

Abstract

An entomological survey was conducted in Cameroon between October 2004 and September 2005, in nine localities targeted for malaria vector control based on adult productivity and variability. Mosquitoes were collected by human-landing catches (HLCs) and pyrethrum spray catches. A total of 12 500 anophelines were collected and dissected: Anopheles gambiae s.l. (56.86%), An. funestus s.l. (32.57%), An. hancocki (9.38%), and An. nili (1.18%). Applying PCR revealed that specimens of the An. funestus group were An. funestus s.s. and An. gambiae complex were mostly An. melas and An. gambiae s.s. of the M and S molecular forms with the M forms being the most predominant. The natural distribution patterns of Anopheles species were largely determined by altitude with some species having unique environmental tolerance limits. A human blood index (HBI) of 99.05% was recorded. Mean probability of daily survival of the malaria vectors was 0.92, with annual mean life expectancy of 21.9 days and the expectation of infective life was long with a mean of 7.4 days. The high survival rates suggest a high vector potential for the species. This information enhances the development of a more focused and informed vector control intervention.

Keywords: Malaria vectors, Altitudinal structuring, Sporogonic cycle, Climate, South-western Cameroon