There’s nothing quite as annoying as the whine of a mosquito. However, in many areas, mosquitoes also mean deadly disease. Malaria alone kills over 1 million people per year, according to the U.S. Centers for Disease Control. There are other scary diseases, too, like the West Nile and Zika viruses. The number of deaths by mosquito are rising and as climate change signals longer breeding seasons for the insect, those numbers are going to increase. What are scientists doing in response? They’re going after the insect’s genes.
Oxitec struggles for approval
For over a decade, a British company, Oxitec, has been modifying mosquitoes. Trials have already been held in Brazil and the Cayman Islands, where the insects reduced the population of a specific breed – Aedes aegypti – by 90%. Getting federal approval from the United States has not been easy, however. For years, the company was actually evaluated by the FDA, despite the mosquito not being a drug or a food. Like a drug, however, they were designed to prevent disease. After all that time, the FDA finally decided the bugs were more like a pesticide. Oxitec now falls under the jurisdiction of the EPA. This makes more sense, and the company hopes it will speed up the approval process.
“Gene drive” mosquitoes cause controversy in Africa
Oxitec isn’t the only company with scientists working on mosquitoes. In 2018, Burkina Faso gave the okay for scientists from three countries (Burkina Faso, Mali, and Uganda) to release up to 10,000 genetically-modified mosquitoes. These insects were all male and designed to be sterile. The wild female mosquitoes would mate with them, but no babies would be born, thereby reducing the overall population. This trial represents the first release ever of gene-driven bugs. The Target Malaria Project headed up the experiment, whose funding comes from billionaires like Bill Gates.
Not everyone was happy, however, and believed the country was being treated like a canary in a coal mine. The experiment was not without risks, either, since there could be females who bite (and spread disease) in the mix. In our research, there were a handful of articles saying that the trial was purely for training purposes, with “no benefits” regarding actual malaria eradication. This makes the release of the mosquitoes problematic, and indeed, the issue of local consent is constantly debated when it comes to these types of experiments.
CRISPR mosquitoes get busy in a lab
The mosquito work continues. In February 2019, NPR witnessed the release of edited mosquitoes into a lab in Italy. Created using CRISPR, these bugs have modified mouths, so they can’t bite, and they can’t lay eggs. Over time, as bugs with these gene mods mate, more and more mosquitoes will be born sterile and unable to bite. The scientists hope that in six months, they’ll be able to tell if the process is effective. Why release them in a lab? There have always been concerns about introducing something new into the environment; it’s one of the reasons why Oxitec has had such trouble getting approval and why the Burkina Faso experiments were controversial. In the Italy lab designed to mimic the mosquito’s wild environment, it’s easier for scientists to observe and the public doesn’t need to worry about edited insects buzzing around.
Scientists aren’t only editing insects to end disease, they are editing food. Click here to read about a banana designed to contain more nutrients.