African scientist could wipe out malaria by editing mosquito DNA
Abdoulaye Diabate faced a life-threatening bout of malaria when he was just five years old. Diabate narrowly survived the mosquito-borne disease, but cousins ages three and four were not as fortunate.
Diabate, who now heads medical entomology and parasitology at Burkina Faso’s Research Institute in Health Sciences, is developing an innovative technique that could potentially wipe out malaria-transmitting mosquito species by altering their genes.
The Burkina Faso-born scientist and professor was awarded the 2023 Falling Walls Prize for Science and Innovation Management for his research, which organizers said “offers hope for malaria control.”
Diabate was named in September as the only African among 10 global winners of the prestigious award for this year and was also recognized by the Falling Walls Foundation for “contributing some of the world’s most advanced work on genetic solutions to malaria.”
The Falling Walls Foundation is a nonprofit organization dedicated to fostering breakthrough thinking.
A leading cause of death
Malaria is a leading cause of death in Diabate’s country, where nearly all of the West African nation’s 22 million inhabitants, especially children, are at risk of the disease, according to the World Health Organization.
Malaria killed nearly 19,000 people in Burkina Faso in 2021, the most recent data from the WHO regional office for Africa showed.
The disease is also one of the main causes of death in the wider African region, which shoulders the world’s largest malaria burden.
For many years, malaria control interventions, including the use of insecticide-treated bed nets, have helped to reduce transmission and deaths in affected countries.
However, “malaria deaths remain unacceptably high, and cases have continued to increase since 2015,” WHO said in April, adding that the upswing in infections was due to the rising cost of providing those interventions as well as the “biological threats” that enable drug resistance and aid vector mosquitoes in developing immunity to insecticides.
Malaria killed an estimated 619,000 people globally in 2021, according to WHO’s last published data.
Around 96% of those deaths happened in Africa, the health body said, adding that 80% percent of casualties on the continent “were among children under the age of 5.”
“Although bed nets are doing a fantastic job … we now have widespread insecticide resistance in the different species of mosquitoes, specifically those that are transmitting malaria,” he said.
“This makes it difficult to defeat malaria with these conventional tools. This is why it is extremely important to innovate and get new tools that can complement the existing ones. (Otherwise) in no way would we be able to defeat malaria.”
The ‘game changer’
Diabate said he is optimistic that his vector control tool for malaria – described as “gene drive technology” – could be the “game-changer” when rolled out.
Malaria is transmitted through the bite of female Anopheles mosquitoes that are infected with the parasitic disease. Male mosquitoes do not bite so are unable to transmit malaria.
With gene drive, female mosquito species that transmit the disease are prevented from producing new female offspring through the release of gene-edited males that are made sterile into the environment.
Diabate said the female mosquito population would be depleted and malaria transmission halted.
“When the (gene-edited) mosquitoes are released in the field … they will spread across the entire mosquito population and cut malaria transmission right away,” he said, adding that gene drive was a more sustainable and budget-friendly malaria control intervention.
“The genetically modified mosquitoes are the ones to do the job for you … unlike the other (malaria control) interventions where humans run from place to place to deliver.
“The good thing about this technology that we are developing is that if it works as expected, it’s not only going to be cost-effective, but it will also be sustainable and can be deployed in remote and difficult-to-access areas in Africa. We believe that once the technology is ready and we release it and it works as expected, it should be able to be the game-changer.”
However, it may take a few more years to roll out gene drive technology in Africa, Diabate said.
In 2019, Diabate’s vector control research alliance, Target Malaria, conducted the first phase of the project by releasing Africa’s pioneer batch of genetically edited mosquitoes in Bana, a village in Western Burkina Faso.
More than 14,000 sterile male mosquitoes were let loose the same day during the controlled release, according to Target Malaria, which added that 527 of the released mosquitoes were recaptured after 20 days.
“While the release was not aimed at impacting malaria transmission, it was a stepping one for the team to gather information, build knowledge, and develop local skills, the research alliance further said in a blog post, adding “this analysis and the data gathered is providing invaluable insights that we are already using in the next phases of our research.”
There have been similar projects targeting mosquitoes DNA.
In 2013, a US biotech company, Oxitec, developed gene-modified mosquitoes that pass on a deadly gene to female species of the Aedes aegypti mosquito that transmits yellow fever, as well as the dengue and Zika viruses.
The offspring of the gene-modified female mosquitoes die in the larval stage.
In 2016, the International Atomic Energy Agency also launched an X-ray powered technique to sterilize male mosquitoes in Latin America and the Caribbean, aimed at reducing the reproduction of female offspring that transmit Zika.
Diabate’s research appears to be among the first using gene editing to target male mosquitoes.
Ecological concerns
Health authorities outside Burkina Faso have welcomed Diabate’s gene drive technology, but questions remain about its impact on the environment when fully released.
Every living creature, even if it appears dangerous or harmful to humans, fulfills important tasks in its habitat.
Save our Seeds, German-based advocacy group
“Gene drive technology has to do with modifying genetic materials … so you never know the new vector that you’ll have and what this will mean to the environment or the ecology,” he said. “It’s something that researchers need to look at.”
German-based advocacy group Save Our Seeds (SOS) has campaigned strongly against gene drive technology, saying its impact on ecosystems cannot be predicted.
“Every living creature, even if it appears dangerous or harmful to humans, fulfills important tasks in its habitat,” SOS said on its website. “The extermination or even manipulation of a species will therefore have consequences for the entire ecosystem,” it added.
The advocacy group explained that mosquitoes are among the major sources of food for many animals such as birds and dragonflies, while recalling that “in the Camargue, a nature reserve in southern France, the decimation of mosquitoes with a biological pesticide … led to a reduction in the number and diversity of birds and dragonflies.”
Diabate said he has dedicated his life to fighting malaria, which he said took a toll on his personal life.
“Malaria has affected every aspect of my personal life: from nearly dying of the disease as a toddler to taking care of my loved ones every time they get sick. I have therefore decided to dedicate my life to fighting this disease that stifles the development of Africa and breaks the future of millions of African lives,” he said.