Dengue fever is a fast-growing and sometimes fatal disease which infects an estimated 390 million people every year. In Abingdon, Oxfordshire, a company called Oxitec is tackling the dangerous disease by genetically modifying its key vector: the Aedes aegypti mosquito. Oxitec’s OX513A mosquitoes are strategically released in areas where dengue occurs to mate with wild mosquitoes. Then – due to a tweak made in a petri dish – the resulting eggs don’t hatch. Within a year, populations of Aedes aegypti mosquitoes subjected to this barrage of tweaked genetic material have been shown to collapse by more than 90 percent.

In Brazil, OX513A mosquitoes were welcomed with open arms in the city of Jacobina where they were released after a major public information campaign headed by Brazilian company Moscamed. After locals had been informed about the workings of the GM bugs, the mosquitoes were released by vans broadcasting Moscamed’s mosquito song through loudspeakers (“Let him come into your house, He’s the solution…”). Within a month, inspection of “ovitraps” where wild females lay their eggs showed that 80 percent of the eggs glowed under fluorescent light: they were spawn of the GM Oxitec mosquitoes and they would never hatch.

For Oxitec, Aedes aegypti is just the start of the process. Other species in Oxitec’s sights include agricultural pests the diamondback moth, the tomato leafminer, the pink bollworm and the Mediterranean fruit fly.

This is an excerpt from ‘This is a mosquito of good‘, which appeared in issue #14 of Delayed Gratification.

Editor’s update 3 Feb 2016:

As Aedes aegypti carries the Zika virus as well as dengue fever, these genetically engineered mosquitoes can impede the outbreak. First detected in Brazil in May 2015, Zika has spread to 22 more countries in South and Central America. Transmitted through mosquito bites, some cases suggest it can also be sexually transmitted. It causes fever-like symptoms and poses a threat of an abnormally small skull in the infants of pregnant women. Oxitec is waiting for FDA approval to begin conducting trials in the Florida Keys.

Marcus Webb is editor of Delayed Gratification, the Slow Journalism magazine which looks back to give the final analysis on stories after the dust has settled, priding itself on being 'Last to Breaking News'.