April 25th marks the day where the international community reaffirms its commitment to the fight against malaria. This year, we can celebrate the fact that our global investments in treatments and preventive measures have made a difference. As noted in the World Health Organization’s most recent World Malaria Report, 2017 saw an estimated US$ 3.1 billion invested in malaria control and elimination by governments of malaria endemic countries and international partners. We understand, at a theoretical level, the steps that we need to take to reach malaria elimination: reduce the ability of mosquitoes to bite people, treat every sick victim with curative drugs, and prevent any infected person from bringing new parasites into the area. Traditional methods include providing bed nets and drugs, building level roads, improving drainage techniques, installing safe water systems and constructing mosquito-proof housing. Even with all these strategies, nevertheless, malaria persists.
But there is still hope. Biologists are developing a way of manipulating mosquito genetics that forces entire populations to self-destruct. The technique has proven so successful in laboratory tests that its authors believe malaria could be eliminated from large regions of Africa within two decades. The scientists alter the genes that disrupt the mosquito’s sexual development leading females to become infertile while the males are able to spread the debilitating gene to offspring. In lab settings, populations of mosquitoes can be driven to extinction within 11 generations and computer models show that wild populations could be decimated within about four years.
There have been previous attempts at genetic alterations, but these have failed as natural mutations over generations overcame the engineered changes--mother nature is a force to be reckoned with. What is different about the newest DNA editing is that the DNA stretch that has been manipulated is vital to mosquito survival, thus at a low risk for naturally occurring mutations.
Should this lab science become translated to “real life,” the fight against malaria conversation will shift from a technical or chemical solution to a social and diplomatic one. Releasing these edited, or “make-believe,” mosquitos into the wild comes with risks as they cannot be disabled or withdrawn; there might be unintended consequences. Though more testing has to be done and safety measures quadruple checked, the next hurdle could be regulatory and ethical approvals, as well as social acceptance.
The ethical debate needs to involve stakeholders living in malaria areas and should consider future generations and the environment. Caution should be at the center of the conversation but as should be the human cost of doing nothing.
Though no gene drive mosquitoes have yet been released in the wild, the future looks promising.