Volume 9 Supplement 2

Parasite to Prevention: Advances in the understanding of malaria

Open Access

Effect of repeated application of microbial larvicides on malaria transmission in central Côte d’Ivoire

  • Emile Tchicaya1, 2,
  • Benjamin G Koudou1, 3, 4 and
  • Jürg Utzinger5
Malaria Journal20109(Suppl 2):P68

DOI: 10.1186/1475-2875-9-S2-P68

Published: 16 December 2010

The effect of repeated application of Bacillus thuringiensis var israeliensis (Bti) and B. sphaericus (Bs) on different entomological parameters and malaria transmission was investigated in a village in central Côte d’Ivoire. First, all potential mosquito breeding sites identified toward the end of the rainy season in a radius of 1.5-km from the village centre were characterized. Next, we applied Bti (0.8 mg/l) and, 3-4 days later, Bs (10 mg/l). The study area was monitored for breeding sites over a 7-month period and microbial larvicides were applied once every 3 wk. Additionally, adult mosquitoes were collected inside and outside human habitations in 4 cross-sectional surveys in 2006 using human landing catches. Repeated application of Bti and Bs showed an effect on Anopheles larvae; in 3 of the last 4 surveys no Anopheles larvae were found, whereas before, 6.5-23.7% of the sites harbored Anopheles larvae. The number of sites positive for Culex larvae decreased after the third treatment round. A total of 2,361 adult mosquitoes were caught in 64 man-night catches; 59.5% of them belonged to the genus of Anopheles, with An. funestus s.l. being the most abundant species. Entomological transmission parameters recorded for 2006 showed a decline in the biting rate of both An. funestus and An. gambiae compared to the preceding year. Moreover, the entomological inoculation rate of An. funestus was significantly reduced (from 328 to 142; P = 0.005) whereas that of An. gambiae remained stable. In conclusion, microbial larvicides might play a role in an integrated approach for malaria control.

Authors’ Affiliations

Centre Suisse de Recherches Scientifques
UFR Biosciences, Université de Cocody-Abidjan
Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute
Liverpool School of Tropical Medicine, UFR Sciences de la Nature
Department of Public Health and Epidemiology, Swiss Tropical Institute


© Tchicaya et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.