Onderwerp scriptie

Factors affecting community-based application of Bacillus thuringiensis israelensis for malaria control in southern Africa

There is a need to find alternative malaria control interventions due to failure of the current strategies attributed to insecticide resistance. Application of the mosquito- specific bacterium, Bacillus thuringiensis israelensis (Bti), is one viable new strategy for malaria control in Africa because it is effective against pyrethroid-resistant mosquitoes, has limited non-target effects, and kills both outdoor- and indoor-biting vectors. However, policy makers have been slow to adopt this strategy due to concerns about the cost of implementation on a large scale.

One potential method of managing implementation costs is to closely involve communities in the application of Bti. This reduces costs through community knowledge  of  the  locations  of  mosquito  larval habitats. Engaging communities also increases community support for the intervention. However, it is not clear whether this implementation strategy would be as effective as government-led Bti application.


We propose to study the effectiveness of community-based Bti application, and factors affecting effectiveness, in an area with high malaria transmission in Malawi. We specifically aim to assess human behavioural and sociocultural  factors that affect the effectiveness of Bti for malaria control.

Experimental approach

A larger project in the study area (Majete Malaria Project, or MMP) is conducting community engagement for malaria education and disease control. The project has set up a randomized trial to test the effectiveness of community-based Bti application (together with other methods of vector control). As part of a PhD thesis at Wageningen University, Mr. Gowelo is studying the effects of Bti application on the larvae of malaria vector mosquitoes. One objective of the PhD research is to assess ecological factors that may impact the effectiveness of Bti. As part of this study, larval habitats will be visited and their ecological factors recorded. To assess effects of habitat factors on larval densities, sampling for mosquito larvae will be done at randomly selected habitats before and after Bti application. Habitat characteristics such as size and vegetation will be recorded during mosquito sampling, and comparisons will be drawn on basis of the habitat factors and larval densities.

The study will run in Malawi from January to,April 2018.