'Gene drive' technology may help eradicate malaria

Diagnoses of diseases transmitted through mosquito, flea, and tick bites have tripled since 2004.

Malaria is the most devastating disease humanity has ever seen. Caused by the parasite plasmodium, it is transferred to humans through a certain species of mosquito. The disease has existed for the entirety of recorded human history. Through medicine and pest management techniques, we have made some headway in reducing its rampage. However, in 2015, it still killed 435,000 people. We need a technological breakthrough to extinguish the danger.

That’s where scientists working on the Target Malaria project in Terni, Italy, come in. Funded primarily by The Bill and Melinda Gates Foundation they are attempting to use CRISPR gene editing technology to eliminate the species of mosquitoes which carry the malaria-causing parasite.

Normally, it is incredibly difficult to influence the genetic code of a wild population. Any trait that is inserted into an organism only has a 50 percent chance of being passed on. The crossbreeding with the natural population results in traits dissaipating in future generations fairly quickly. In order to edit the genetic code of an entire population, you would need to release many times the native population worth of mosquitos. Obviously this is a non-starter, as it would be a bit like putting out a fire with a nuclear missile.

There is a clever new solution to this problem though. A technique known as “gene drive” makes it possible to guarantee a trait is passed on to its children. A gene drive edited organism has the desired code in its DNA, but it also has a gene that can further modify genetic code. It allows females to alter the genetic code of their eggs before they are laid. Thus the gene will continue to force itself to be passed on.

Gene drive grants us much stronger control over wild populations. The scientists in the Target Malaria project are not trying to change the Anopheles Gambiae mosquito to no longer be able to carry the plasmodium parasite. They wish to eliminate the mosquito species all together. They plan to insert a gene which will cause female mosquitos to be infertile once they receive two copies of the gene – that is, from both their mother and their father. The benefit of this is that it allows the gene to spread but causes the population to crash.

Removing a species from an ecosystem may seem like risky move, but Rob Stein, a member of the Target Malaria project, insisted in a Q&A with NPR it’s okay.

“There are hundreds of mosquito species, so many that scientists think dramatically suppressing, or even completely removing, just one would not significantly impact the food chain,” Stein said. “Many other mosquito species would still available for these animals to eat.”

Some critics claim that we can never really know how we are going to impact the ecosystem with projects like this, but that is a ridiculous standard to keep.

We already interfere with our environment to a massive degree. Attempting to end the most blood thirsty disease on the planet seems like a much better experiment than seeing what happens if we cut down the Amazon rainforest. Humanity has hunted animals such as woolly mammoths to extinction with no apparent devastating consequences, so one species of mosquito that does not appear to be a keystone of the ecosystem seems like a small price to pay.

I find it hard to imagine a situation that is worse than the malaria epidemic, so even if there is minor ecological harm, we should still enthusiastically go forward with the project.

Defeating malaria would stand as the highlight of the early 21st century. It could be regarded as the turning point that helps propel sub-Saharan Africa into prosperity. The 12 billion dollars a year of harm malaria does to the continent would now be able to go towards other needs, like clean water and economic development. With this in mind, it should be an easy choice for us to make.


Matthew Nota is a contributor for The Daily Campus. He can be reached via email at matthew.nota@uconn.edu.