Can Genetically Modified Mosquitoes Be Helpful in Eradicating Mosquito-borne Diseases?

A genetically modified Anopheles gambiae mosquito 

Mosquitoes have long been associated with other animals as life-threatening parasites. Although they are food for some animals such as dragonflies and damselflies, mosquitoes have been and continue to be a threat for most animals, including humans. As carriers of some of the most lethal diseases, including malaria, mosquitoes have been responsible for more human deaths throughout history than all the wars and famines combined. Despite the development in vaccination and general precautions against such diseases, mosquitoes, particularly those of the genus Anopheles, claim more than 400,000 lives every year. But recently, a brand-new experiment is being done that could change the ongoing battle against malaria. It is a new kind of genetic engineering that can quickly spread a self-destructive genetic modification through a complex species.

Plasmodium parasite; the main cause of malaria

The scientists involved in this project used an innovative gene-editing tool called CRISPR to create mosquitoes with a "gene drive," which quickly transferred a sterilizing mutation through other mosquito species. A report in Nature Biotechnology showed that nearly all regular mosquitoes were wiped out by the ones carrying the mutation in a high-security basement laboratory in London. The researchers are especially heartened because, unlike in most attempts to use gene drives, the modified mosquitoes did not seem to further mutate in a way that would belittle the effectiveness of the mutation. However, they underlined that several years of supplementary research are required to further analyze the effectiveness and safety of the approach before anyone tries to release these mosquitoes or any other organisms engineered this way into the wild. The researchers also recognized that the technology brings serious concerns, indicating that it will need an extensive political debate, meticulous regulation and the agreement of people living in any areas where the mosquitoes might be released.

Nnimmo Bassey, one of several activists opposed to the technology of using genetically modified mosquitoes against malaria.

Target Malaria, a program promoting the research, has already started comprehensive discussions with African countries where the mosquitoes could one day be released. Nonetheless, there is already strong opposition among some activists like Health of Mother Earth Foundation director Nnimmo Bassey, who stressed that Africa has become a "testing ground for a technology that no one can say is safe definitively." Others like biologist Ricarda Steinbrecher of ECONEXUS added that wiping out or greatly suppressing an entire malaria mosquito species could lead to other more questionable species coming in to fill a niche. Jim Thomas, co-executive director of an international technology watchdog organization ETC Group, voiced his concern that the gene drives could be used to develop new biological weapons. Andrea Crisanti, a molecular parasitology professor from the Imperial College London who led the research, rejected the approach that gene drives could be used to create biological weapons. Although he recognized the concerns, which have been considered by many scientific organizations, Professor Crisanti and others stressed that the possible advantages surpass the risks. The gene drive technology could also be used to significantly suppress other mosquito species, such as those that spread other life-threatening diseases like dengue and Zika. In addition, gene drives could also be used battle agricultural pests.

Standing water containing mosquito larvae

I find it extremely fascinating that a team of researchers have come up with a plan to battle mosquitoes carrying the malaria. Based on the experiments they conducted, they are hopeful that releasing genetically modified mosquitoes in countries known for malaria would change the game in the battle against the disease, especially when there are mosquitoes that are resistant to pesticides. However, I also believe that it is important to note that there is still a great need of supplementary research needed to further study the safety and effectiveness of this approach before these mutation-carrying mosquitoes are released. This is especially true considering the concerns addressed by people like Dr. Steinbrecher, who pointed out that suppressing mosquitoes carrying the malaria virus significantly could result in ecosystem crashes especially when other more problematic species fill the niche. In addition, if ordinary mosquitoes are destroyed by their genetically modified counterparts, what will happen to animals that prey on mosquitoes like dragonflies, damselflies, and mosquitofish? Will they be able to survive on the ones carrying the mutation? This is why it is highly essential to further study these genetically modified mosquitoes to prevent any possibility of an ecosystem crash. In the meantime, emphasis should continue to be placed on preventing and treating malaria and other mosquito-borne diseases through vaccination, elimination of standing water, setting up mosquito nets and window screens, wearing long-sleeved clothes, and applying insect repellents.

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