Project Lead(s): Marta Maia
Issue
Malaria is one of the major threats to public health and economic development.
Until now, insecticide-treated bed nets have led the fight against malaria. However, to reach elimination and avoid further malaria resurgence, the fight against the malaria mosquito requires new, innovative and sustainable interventions to complement current control strategies.
Solution
The project sought to develop a sugar lure capable of attracting and killing malaria mosquitoes.
Ivermectin was chosen as the mosquitocidal ingredient, because of its high safety profile and also because it is easily available in remote locations in East Africa.
Several lure designs were tested, using plastic bottles and containers of different shapes and sizes, different cloth colours and different fruit concoctions, as well as different ways of providing a wet sugar surface for the mosquitoes to feed on.
Most mosquitoes preferred to feed on plain 10% sugar solution rather than on fruit juices, and the best prototype design consisted of a bucket with a piece of old mattress soaked in sugar solution containing ivermectin and lined with black cloth in its inner surface.
This design attracted a significantly high number of mosquitoes, as they like to rest in dark and humid places.
A community-based social study was conducted to collect data on general health behaviours and knowledge of malaria: prevention, treatment and socio-economic impacts.
The project developed an effective toxic mosquito lure for less than $0.10 US/unit. These lures were tested in a semi-field system (hut) with volunteers for 16 nights, to determine their best location.
A total of 250 mosquitos were released from a mid-point inside each hut.
Outcome
Results show that 50% of the recaptured mosquitoes had taken a sugar meal from a lure and that 33% had sought a sugar meal outdoors before entering a hut in search of a human blood meal.
It was concluded that the malaria vectors were choosing to take a sugar meal before seeking a blood meal. This may be a method for the mosquito to obtain a small amount of energy needed for the host-seeking process.
The fact that most mosquitoes only took half a sugar meal suggests that they preferred not to engorge on sugar solution, in order to still have enough ‘space’ for a blood meal.
This has not yet been described in the literature and the team intends to publish these results.
The research team intends to apply for Transition To Scale Phase II, funding to improve the sugar lures to accommodate the suggestions provided by the community.
The next steps would be to optimize the lures and further validate the prototype in a clinical trial.
The team anticipates scaling up the intervention and conducting a cluster randomized controlled trial in two ecologically different field sites – a sugar-poor environment and a sugar-rich environment – to investigate whether the innovation in association with treated nets can reduce malaria prevalence.