Anti-mosquito innovation boosts malaria battle
In the long-running fight against malaria in Africa, current anti-mosquito measures are reaching their limits. An EU-funded project has developed new ways to protect people and prevent the spread of the potentially fatal disease.
© Ray Wilson
Malaria is transmitted by mosquitoes carrying parasites that cause the disease. In Africa, indoor insecticides either on bednets or sprayed in the home have had huge success in helping to prevent malaria. But there is still more to be done, in part since mosquitoes are adapting to these protective measures and not everyone at risk has access to them.
Among other tools, the EU-funded AVECNET project has developed novel insecticide delivery methods and evaluated new repellents that target resistant species and help protect particularly vulnerable people.
As part of its work, the project also designed new methods for learning more about mosquito behaviour and advanced knowledge on why some mosquitoes resist insecticides. It also strengthened African anti-malaria research capacity.
“We are pleased with what we have done,” says project coordinator Hilary Ranson of the Liverpool School of Tropical Medicine in the United Kingdom. “We achieved most of our original objectives and have secured funding for multiple follow-on studies.”
Another key outcome is a patented new bednet design, which resulted from AVECNET’s new information on mosquito behaviour. The design uses only small amounts of alternative chemicals on top of the net rather than a standard insecticide on the whole net. “AVECNET research showed that mosquitoes target humans from above, attracted by breath,” says Ranson.
This design widens the range of chemicals that can be used as there is less risk of the insecticide being swallowed if the net is touched or licked when used by children. It also reduces the cost as only a smaller area is treated.
AVECNET also conducted the first-ever clinical trial of a new type of bednet that combines insecticide with a sterilisation product for resistant mosquitoes.
“Bednets protect people under the net but not people without nets or with damaged nets,” explains Ranson. “The sterilisation agent adds protection for everyone by reducing the numbers of resistant mosquitoes.”
The new bednet was selected from AVECNET’s initial analysis of various anti-mosquito measures, including insecticide-treated cattle, mosquito traps and repellents. “We mapped out possible interventions, ideas or missing data,” says Ranson.
Pilot studies were then conducted to fill in evidence gaps and this net was selected for the full clinical trial.
Information for the barrier net design came from an indoor mosquito tracking system designed by AVECNET to learn more about how the insects approach people and bednets. This is now being used to evaluate new and existing insecticides and to improve the design of nets and other interventions.
Other project innovations to improve mosquito research include:
Direct stakeholder input was also tested. People in local communities were given disposable cameras to record data for mosquito control, while stakeholder groups proposed ways of introducing new tools more quickly.
“These gave unexpected results,” says Ranson. “For example, in Côte d’Ivoire, we discovered an insect resistance hot spot through discussions with villagers.”
AVECNET’s results have been widely shared, helping advance efforts against malaria, while its workshops and training have strengthened African research capacity.
Through their experience with the project, researchers and project partners have received financial support for new work, including from the Bill & Melinda Gates Foundation, the Wellcome Trust and the United Kingdom’s Medical Research Council.
In total, over EUR 30 million in grants have been awarded to AVECNET participants, much of which has gone to African partners, says Ranson.