Can genetically modified mosquitoes eradicate malaria?
We investigate whether GM mosquitoes created in labs can be the new hope in the fight against malaria, Zika and dengue.
Aedus aegypti is the ultimate pest. The small, dark female mosquito transmits deadly viruses, like dengue fever, chikungunya, malaria and the Zika virus.
Their eggs can last up to a year without water and they can “travel” on planes, trains, and automobiles. That’s how these insects have infested global populations.
“Dengue fever has been increasing almost 30 times in the past 30 years. It’s increasing all around the world and it’s spreading fast,” says Derric Nimmo, product development manager at Oxitec, a British biotechnology company.
Currently, there is no vaccine or treatment for either Zika or dengue. The only way to fight the spread of the disease is to limit the insect population.
“As scientists, we’ve been fighting a losing battle against mosquitoes. They kill one person every 12 seconds. There’s a desperate need for new technology,” says Andrew McKemey, field operations, Oxitec.
British biotechnology company Oxitec has engineered male mosquitoes to pass a fatal gene on to their offspring, which kills them before they reach adulthood. When released into the environment, Oxitec’s mosquitoes can, in ideal circumstances, suppress the proliferation of mosquitoes and ultimately cut down on the mosquito-borne diseases.
We've been fighting a losing battle against mosquitoes. They kill one person every 12 seconds. There's a desperate need for new technology.
The hope is that if the deadly male mates with wild females, the population will thin. This could potentially save hundreds of thousands of human lives.
However, not everyone is convinced. For instance, residents of Key West, Florida are split over whether they agree that genetically modified mosquitoes have a place in fighting the spread of vector-borne diseases.
Those opposed to GM mosquitoes argue their presence is unnecessary, since mosquito-borne outbreaks have been largely under control in their community.
But their local mosquito control departments are in a constant fight against the outbreaks. The Keys experienced a dengue fever outbreak in 2009, which was eventually eradicated.
And while the Keys has been dengue-free since, their mosquito control’s district can only control the population of mosquitoes down to 50 percent. This has compelled them to look towards Oxitec’s genetically modified solution.
Fifty percent reduction rate “is not enough to prevent dengue transmission,” says Nimmo, manager of product development. He believes his company can do better.
According to Oxitec, field trials in the Cayman Islands, Panama and Brazil reduced the mosquito population by 90 percent. In fact, in 2015, a scientific advisory panel to the government of Brazil approved the release of the Oxitec mosquitoes to control a dengue outbreak.
To verify those numbers, Danielo Calvahlo, from the University of Sao Paulo, analysed the data. According to him, it’s only a 60-70 percent reduction rate as opposed to 90 percent, calling to question Oxitec’s methods.
So can genetically modified mosquitoes help eradicate dengue or malaria?
On this episode of TechKnow, the team travels to London to visit Oxitec’s headquarters, witnessing first hand how a genetically modified mosquito is engineered in the lab. TechKnow also meets Anthony James, professor of microbiology at the University of California, Irvine, who is genetically modifying mosquitoes to make the insects resistant to malaria, which will prevent the spread of the deadly disease.