Project Lead(s): Dickson Lwetoijera
Globally, mosquito-borne diseases affect about 700 million people annually, and malaria alone causes 21,000 deaths in Tanzania.
Current methods of treating mosquito-breeding sites are limited by the inability to find these sites in rural settings, calling for an innovative approach to address this issue.
The project aimed to use rural residents’ knowledge to find water bodies during the dry season and accurately identify aquatic habitats that can be treated with larvicide pyriproxyfen (PPF), to render the sites unproductive to mosquitoes in rural communities of Tanzania.
Dry season mosquitoes’ aquatic habitats are good targets for intervention because, although they are few and scattered, as well as being very hard to locate, they are important in sustaining remaining mosquito populations and the associated malaria transmission. The team crowd-sourced information from rural residents who use these habitats to water their cows/animals.
During the study, 32 registered rural residents were identified in three villages (Mofu, Ihenga and Ikwabi) located in Mofu, Kilombero Distirict.
In collaboration with a project team, these residents successfully identified 33 aquatic habitats, of which 12 were permanent and included in the study. Environmental features within and around the habitats that influence their attractiveness to mosquitoes were catalogued, and the suitability and productivity of the habitats for mosquitoes, as well as impact of introduced PPF on mosquito larvae and pupae, were established through larvae sampling.
PPF intervention was conducted by a trained project team using recommended protocols, by treating six habitats and leaving six untreated for comparison during the dry season.
Following the introduction of PPF in the selected aquatic habitats, approximately 98% of all collected larvae failed to emerge to adults (i.e., died at larvae stages or at pupae stage during emergence).
The impact of PPF on overall mosquito density reduction was not conclusive at the community level, because of the project time limitation and complexity in study design.
These findings on the impact of PPF on larvae and pupae in aquatic habitats form a strong basis for follow-up studies, to establish the impact of the PPF intervention on adult mosquito densities and reduction in malaria prevalence at the community level.