Thu | Sep 21, 2017

Tech Times | Let's kill the mosquito - 'We should use new genetic technology to eradicate the disease-causing bug'

Published:Monday | July 4, 2016 | 7:00 AM

Humans have driven species to extinction through our hunger, ignorance, desire for economic growth, and indifference. Will one species of insect be the first we eliminate for humanitarian reasons?

The insect is Aedes aegypti, commonly known as the yellow fever mosquito and, in recent years, as the dengue mosquito for the way it spreads a haemorrhagic disease that disproportionately affects small children and has high public health costs. Now it's suspected of transmitting the Zika virus, linked to microcephaly in newborns.

Once confined to a small region of sub-Saharan Africa, Aedes aegypti has invaded the Americas, Asia, the South Pacific, and Australia within the last few hundred years. While people have long called for the mosquito's eradication, the recent development of 'gene drive' technology makes this a real possibility. Unlike an ordinary gene, which is passed on to just half of all offspring, a gene-drive construct could be passed on to virtually all offspring. It can be used to spread genes that destroy female mosquito chromosomes, prevent female mosquitoes from flying, or determine whether a mosquito becomes a male.




By releasing a small number of gene-drive mosquitoes, we could reduce each generation of wild females until they disappeared completely. Within weeks, all the males would die out, too, along with the genetic modification that caused their disappearance. Though there are certainly technical and regulatory milestones ahead, what would happen if it worked? First off, it would save more than 20,000 lives per year from dengue alone and prevent millions of cases of illness. In addition to stopping dengue, Zika, and other viruses such as chikungunya, eliminating this mosquito would prevent the spread of other obscure viruses that have been catalogued and may be waiting their turn to cause the next epidemic.

What about the ecosystem? As a species, we are guilty of repeatedly taking actions without thinking about the effects on the environment. Considered in isolation, anything that damages 'the ecosystem' sounds bad. But this ecosystem is cans, buckets, pots, trash, tires, and whatever else is lying around collecting rainwater. Aedes aegypti doesn't breed in ponds, marshes, swamps, or wetlands, and thus there are no frogs and no fish to eat these mosquitoes - one reason they've done so well as a species. Currently, our ability to control dengue (and now Zika) is dependent on our ability to remove the places where Aedes aegypti lives and breeds. If we are willing to destroy an entire ecosystem (that is, clean up garbage and screen over water storage containers), why not eliminate just this mosquito instead?

- MIT Technology